A Social Network Analysis of the EMAC Annual Conferences 2000-2010 1. Introduction In recent years there has been a growing interest in the nature of scientific collaboration. Collaboration between researchers play an important role in scientific development in general and consequently, numerous studies have showed an increase in the number of co-authored research papers (Laband and Tollison, 2000; Moody, 2004). Members of social institutions of science over a broad range of disciplines co-author research papers together creating social networks of researchers. These social networks play a crucial role in scientific growth as they work to share and generate new knowledge through social interaction (Crane, 1972). The manner in which authors influence each other when collaborating on joint publications is important in the process of producing knowledge (Bourdieu, 2005). Social Network Analysis provides a mean for interpreting and measuring relationships between a number of social entities, such as people, groups and organisations. The emphasis on relationships is an important supplement to standard social and behavioural research, which is mainly concerned with attributes of the social entities (Wasserman and Faust, 1994). In Social Network Analysis the attributes of the individual actors are not essential, the focus is on the structure of their relationships and how the structure of linkages affect individual actors and their relationships. The structure of a network provides insights into network activities and how knowledge is generated and shared within the network. An efficient way for scientific researchers to exchange and bring forth knowledge is through collaboration in specialist organisations such as the European Marketing Academy. The structure in networks like this is often hidden because of its informal network characteristics. To date little attention has been paid to the application of Social Network Analysis in a conference setting. The objective of the study at hand is to employ Social Network Analysis to analyse the research collaboration within a specific academic group over time, namely the European Marketing Academy. It should be seen as a contribution to the existing literature in the field of Social Network Analysis as it provides a review of previous literature relating Social Network Analysis and co-authorship. Furthermore, it 1 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 adds to the limited number of empirical studies applying Social Network Analysis in a conference setting. The current study will focus on the structure of the EMAC community by analysing the way in which researchers of this specific network collaborate. The patterns and regularities in the choice of collaboration partners of members of the EMAC community will be unveiled to discover if general assumptions can be made concerning the manner in which these researchers work together. 1.1 Problem Statement A considerable amount of research can be ascribed to members of the European Marketing Academy over the past 35 years. The vast majority of scientific papers presented at the academy´s annual conference have been co-authored by two or more researchers. The way in which these academics choose to work together is characterised by the absence of any formal hierarchy. The creation of knowledge is often a joint process where patterns and regularities in the way in which scholars work together emerge. These patterns and regularities provide valuable insight into how knowledge is created and shared within groups of researchers and can also give ideas to what powers such networks. By using Social Network Analysis as a sociological approach for analysing patterns of relationships and interactions between researchers, the underlying social structure of a scientific collaboration network can be discovered. In order to understand the research community of the European Marketing Academy better it is relevant to gain insights into the morphology of the network in terms of clustering to establish the grounds on which the researchers in the EMAC community select their collaboration partners. The aim of the study at hand is to demonstrate if patterns and regularities in the way in which authors work together exist within the European Marketing Academy by performing a Social Network Analysis. It will seek to answer the following research questions: 2 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 What are the characteristics of the structure of the European Marketing Academy scientific collaboration network? Which factors influence the choice of collaboration partners in the European Marketing Academy scientific collaboration network? 1.2 Structure In order to give a background for the current study, the section “Background” will provide a description of the concept of Social Network Analysis and give an introduction to the European Marketing Academy. The literature review will then review previous literature linking Social Network Analysis and co-authorship, presenting the main findings of these studies. This is followed by the methodology section, which explains the methods applied, the unit of analysis and the constructs utilised in Social Network Analysis. The section then continues with a description of how the data set was constructed and finishes with a detailed desription of the measures employed in Social Network Analysis. The results section will present the findings of the study. This section is followed by a discussion of the results.The study at hand will then review the limitations and give suggestions for further research in the field. The study will conclude with an assessment of the main findings. 2. Background 2.1 Social Network Analysis Social Network Analysis concerns the comprehension of the connections among social actors and the consequences of these connections. It reveals a structure of linkages, within which actors are embedded. Actors are described by their relations, not by their attributes and the relations are just as fundamental as the actors that they connect. As a tool Social Network Analysis has its roots in the social sciences. The central concepts of relation, network and structure originates from a number of disciplines within the social sciences such as sociology and anthropology. Social Network Analysis has gained wide use in disciplines as diverse as economics, marketing and industrial engineering. This can, in part, be ascribed to the fact that Social Network Analysis provides insight into aspects of the political, economic and social structural environment (Wasserman and Faust, 1994). 3 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 In general, Social Network Analysis can be defined as a structured way of analysing relationships within groups (Cross, Borgatti and Parker, 2002) by “providing a rich and systematic means of assessing informal networks by mapping and analysing relationships among people, teams, departments or even entire organisations” (Cross, Parker, Prusak and Borgatti, 2001: 103). In order to asseess the characteristics of a network Social Network Analysis utilises a unique set of diagnostic tools. The set of methods and analytic concepts used in Social Network Analysis have been developed over the past 50 years as an inherent part of progress made in social theory, empirical research and formal mathematics and statistics (Wasserman and Faust, 1994). Social Network Analysis has a broad range of application possibilities. One such is the analysis of informal networks of academics collaborating on research papers. As this type of network is characterised by the absence of any formal hierarchy, a Social Network Analysis could reveal patterns and regularities in the way in which academics work together to generate knowledge. Furthermore, it could disclose the structure that shape the creation of knowledge within a given field of research (Vidgen, Henneberg and Naudé, 2007). 2.2 The European Marketing Academy The European Marketing Academy (EMAC) was founded in 1975 as a professional society for individuals involved or interested in marketing theory and research. The objective of the society is to act as the core of a communication network for distributing information and promoting international exchange in the field of marketing. The Academy currently has more than 1000 members from more than 57 different countries and is the largest European community of marketing scholars (http://www.emaconline.org/r/printPage.asp?iID=IHGMD). The majority of EMAC members joined the Academy after hearing about it from a colleague. The social aspect of being a member of EMAC is very important to especially the younger members, who consider network opportunities and career development a significant reason for joining the community. Particularly the posibility 4 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 of participating in the annual conferences attracts many researchers to the Academy (Wong, 2010). The highlight of the year for the European Marketing Academy is the annual conference held at a major university or scientific institute in Europe. The conference serves as a forum where members exchange ideas and present and discuss research projects in all areas of marketing (http://www.emac- online.org/r/printPage.asp?iID=IIKFF). It is the scientific collaboration of authors presenting research papers at the annual EMAC conference that forms the basis of the study at hand. One of the core activities of EMAC is the publication of the A level journal International Journal of Research in Marketing (IJRM). The journal has served as EMAC´s flagship journal for more than 25 years. The number of submissions has seen an increase in recent years in addition to the enhancement of the quality of articles submitted to the journal (Dekimpe, 2010). Besides IJRM, the Academy publishes The Chronicle, which is a bi-annual publication informing members of ongoing activities in the marketing discipline. Additionally, the Academy publishes an online newsletter in order to keep members up to date with the activities of the Academy (http://www.emaconline.org/r/printPage.asp?iID=IHGMD). 3. Literature Review In recent years, there has been an increasing amount of literature on Social Network Analysis. This large and growing body of literature has, among other things, applied Social Network Analysis as a tool for conducting citation analyses (see for instance Zinkhan, Roth and Saxton, 1992 and Carter, Leuschner and Rogers, 2007). Additionally, a large volume of published studies employ Social Network Analysis to reveal patterns and regularities in the way in which scholars work together by focusing on co-authorship in published research papers (e.g. Newman, 2001a; Newman, 2001b; Barabási, Jeong, Néda, Ravasz, Schubert and Vicsek, 2002; Liu, Bollen, Nelson and Van de Sompel, 2005). So far, however, only limited attention has been paid to the application of Social Network Analysis in a conference setting. 5 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Co-authorship is the most formal expression of intellectual collaboration in scientific research (Acedo, Barroso, Casanueva and Galán, 2006). Social Network Analysis pertains to the comprehension of the linkages among social entities and the implications of these linkages. As a tool Social Network Analysis has its origin in the social sciences. As mentioned above the central concepts of relation, network and structure originates from a number of disciplines within the social sciences such as sociology and anthropology (Wasserman and Faust, 1994). Social Network Analysis has gained wide use in a broad area of disciplines (Eaton, Ward, Kumar and Reingen, 1999; Laband and Tollison, 2000, Newman, 2001b; Barabási et al., 2002; Morlacchi, Wilkinson and Young, 2005; Vidgen et al., 2007; Henneberg, Jiang, Naudé and Ormrod, 2009). The tendency for co-authorship has been increasing across almost all scientific disciplines. Various explanations for this trend has been put forward. First, the cost of equipment for conducting scientific experiments in the natural sciences is rather high and this might encourage collaboration. In the social sciences, researchers are not as dependent on labs, however, large-scale data collection induces collaboration as researchers can share the heavy workload. Second, scientific collaboration provides better opportunities for specialisation and division of labour as it is far more efficient to bring in a new scholar than to learn new material oneself. This often results in specialists being brought in to conduct the analyses (Laban and Tollison, 2000; Moody, 2004). In a case study of the International Marketing and Purchasing (IMP) Group 1984-1999, Morlacchi et al. (2005) used Social Network Analysis to analyse research collaboration, in the form of co-authorship, within this specific academic group over time. The focus of the study was on the people relationships inside the IMP Group based on coauthorship reported in the proceedings of the annual IMP conferences. In their study, Morlacchi et al. (2005) selected a sample from the population of interest which comprised authors who had attended 3 or more annual IMP conferences and who therefore had been involved in 3 or more papers. This was done to center the study on more active members of the group who would attend the annual conference on a regular basis and present papers that would add to the generation of new knowledge in the field. A serious weakness to this methodology, however, is that imposing such a restriction will cause the study to give an inaccurate picture of the structure and operation of the IMP Group, as scientists who have produced less than 3 research papers obviously also contributes to the creation of new knowledge within the field. By omitting certain 6 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 scientists, the study will not convey the true nature of the research collaboration network of this specific academic group. In contrast to the methodology of Morlacchi et al. (2005), Henneberg et al. (2009), in investigating the same academic group (i.e. the IMP Group, 1984-2006), utilised all papers presented at the annual IMP conference to give a coherent picture of the IMP community. In doing so an artificial boundary to the network was created. Vidgen et al. (2007) points out that excluding all co-authored papers not presented at the conference is a methodological disadvantage, a disadvantage they, nevertheless, are willing to accept. Newman (2001b) conducted a comparative study of co-authorship focusing on three fields of research, namely physics, biomedical research and computer science. In order to make valid comparisons of collaboration patterns in the three different fields a fairly short time window of five years was used. This implies that the collaboration network was kept static during the study and that time evolution of the network was not examined. This research approach differs from that of Barabási et al. (2005). In their different, but complementary, approach to collaboration networks Barabási et al. (2005) mapped the electronic database of journals in mathematics and neuro-science over an 8year period in order to derive the dynamic and structural mechanisms that regulate the evolution of the collaboration networks in the two fields. Similarly, Morlacchi et al. (2005), Vidgen et al. (2007) and Henneberg et al. (2009) conducted longitudinal studies of time periods of minimum 13 years to infer the evolution of the complex systems investigated. A number of studies have found that the distribution of the number of co-authored research papers does not follow a normal or bell shaped distribution. Instead it follows a power law distribution where few scholars contribute a large number of co-authored papers and where many authors contribute a small number of co-authored papers indicated by the long tail of the distribution (Lotka, 1926; Newman, 2001b; Barabási et al., 2002; Morlacchi et al., 2005). Previous research have found the research communities under examination to not be fully connected due to the existence of clusters. In other words, the networks contained 7 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 subgroups which were not connected to other subgroups through paths between authors (Vidgen et al., 2007; Henneberg et al., 2009). However, despite the lack of links between a number of subgroups the main component of the IMP Group network showed a relatively robust network structure facilitating information dissemination through the network (Henneberg et al., 2009). In comparison, the network of ICT researchers presented by Vidgen et al. (2007) exhibited a quite delicate nature where the removal of a few key authors would lead to a division of the main component into subcomponents. Morlacchi et al. (2005) demonstrated a tendency for geographical grouping within the IMP Group. This trend becomes evident as disconnected subgroups emerge in the network containing researchers from only one country. A possible explanation to the appearance of such subgroups could be the language barrier. These findings are supported by Liu et al. (2005) who, in their study on co-authorship in the digital library research community, found collaboration between authors from different countries to be a mere 7 %. Recent evidence suggests a degree of preferential attachment within social networks of collaborating auhtors as researchers tend to be organised around institutions and collaborate closely within specific clusters and groups of interest (Eaton et al., 1999; Barabási et al., 2002; Liu et al., 2005). Although research communities grow over time given that more academics join in to express their intellectual ideas, they often form “small worlds”, by which the average separation between the individual researchers is shorter than would appear from random data (Vidgen et al., 2007). In their study of the IMP Group, Morlacchi et al. (2005) found the network to be highly clustered, where some researchers collaborate extensively within the network and play a key role in linking different parts of the network. This result is supported by Newman (2001b), who reported that networks of collaborating scholars form “small worlds” as the typical distances between scholars within the networks are small. Barabási et al. (2002) showed that even though networks grow over time, the average distance between any two scholars actually decreases over time, lending support to the idea of networks forming “small worlds”. Similarly, Moody (2004) reports that the pattern of co-authorship within the discipline of sociology shows a “steadily growing cohesive core” (2004: 235). However, in contrast to the results mentioned above Vidgen et al. (2007), in their study on co-authorship in the European Conference on Information Systems, 1993-2005, found that the main component of this 8 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 specific research community displayed few properties of a “small world”. Components with 15 or more actors did indeed demonstrate “small world” characteristics. Still, if one of the scholars in one of these smaller components co-authors a scientific paper with a researcher from the main component, the smaller component will be absorbed into the main component. This surprising result is interestingly enough backed by the results of the study conducted by Henneberg et al. (2009). They found there to be a core within the IMP Group where there were fewer small clusters working on their own. This would indicate that the IMP Group displays more of a “large world” disposition, in which it is more probable that the actors are connected through co-publishing, and thus expressing the same opinions. This result is surprising because the earlier study of the same academic group conducted by Morlacchi et al. (2005) provided results supporting the “small world” view. An additional interesting topic presented in earlier literature concerns the presence of so-called “invisible colleges” within social networks. According to Crane (1972), social interaction between researchers play a role in scientific knowledge development. She sees the growth of scientific knowledge as a sort of diffusion process where central actors in a social system, who have adopted an idea, influence other actors who have yet to adopt this new idea. These networks of highly productive scientists form “invisible colleges” which hold a key role in disseminating knowledge throughout fields of research. These informal communication networks or “invisible colleges” work to link separate groups of scholars within a research area and to provide coherence and direction within the field (Crane, 1972; Morlacchi et al. 2005). The presence of “invisible colleges” within social networks were found in a study on co-author relationships and author productivity in consumer behaviour research conducted by Eaton et al. (1999). The structure of the research community under investigation revealed trace characteristics of an “invisible college”. It showed the relation of collaboration among highly productive authors and their importance in securing the intellectual structure of the field. Henneberg et al. (2009) found strong cohesion between groups of centrally important actors in the IMP Group indicating continuous collaboration over time and thus lending support to the notion of “invisible colleges” as centres of knowledge creation. The findings of Morlacchi et al. (2005) corroborates the results presented by Henneberg et al. (2009) as they also found an 9 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 “invisible college” to be present within the IMP Group connecting subgroups of researchers from different countries. A limitation to a number of previously conducted studies on co-authorship is that they only consider one aspect of research collaboration (Eaton et al., 1999; Newman, 2001b; Barabási et al., 2002; Liu et al., 2005; Morlacchi et al., 2005; Henneberg et al., 2009). Vidgen et al. (2007) extended their research to include two types of relationships, namely co-authorship and panel membership. Nevertheless, the authors still name the limited types of relationships investigated as the chief weakness to their study. Focusing on co-authorship in a conference setting, Morlacchi et al. (2005), Vidgen et al. (2007) and Henneberg et al. (2009) neglect to include co-auhtorship in books and journal articles outside of the conference setting, which is a disadvantage as these are also important ways for co-authoring researchers to publish their ideas. In his study on the strength of weak ties between actors in a network, Granovetter (1973) argued that the stronger the tie connecting two individual actors, the more similar these actors will be. According to his argument this also implies that if strong ties connect actor A to actor B and actor A to actor C, then actor B and actor C will both be similar to actor A and thus similar to each other. This will in turn increase the likelihood that actor B and actor C will forge a friendship once introduced. Furthermore, in stressing the importance of weak ties, he reasoned that information can reach a larger number of people and cover greater social distance when passed through weak ties rather than strong ties (Granovetter, 1973). This is due to the fact that weak ties connect individuals in otherwise separate clusters whereas strong ties tend to share the same connections (Burt, 1995). That is, the people an individual is weakly tied to move in different circles and will therefore be able to spread information to a wider network (Granovetter, 1973). 4. Methodology The present study will follow the methodology used by Vidgen et al. (2007) and Henneberg et al. (2009) and will analyse the pattern of co-authorship in research papers presented at the European Marketing Academy annual conferences between 2000 and 10 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 2010. It will, however, differ from the two abovementioned research papers, in that it will analyse the years of the conference individually and not cumulatively. The unit of analysis is the co-authored, scientific conference paper, i.e. all research papers presented at the EMAC conferences 2000-2010 with two or more authors. This means that the type of relationship studied is co-authorship. By focusing the study on co-authorship rather than citation, emphasis is placed on the social relationships of a network as it must be assumed that authors co-authoring a scientific research paper have an actual social relationship. In accordance with Vidgen et al. (2007) and Henneberg et al. (2009), the analysis of the 11 years of EMAC conferences will adopt a longitudinal view of discreet data points (i.e. the annual conferences). The network analysis of the study at hand aims at mapping the development of the network of the EMAC community over the past 11 years. The focus of the study will therefore be on the years 2000 to 2010 neglecting conferences held prior to this. In order to give a coherent picture of the development of the network in the time period under investigation the current study will concentrate on the years 2001, 2004, 2007 and 2010. Social Network Analysis makes use of two constructs: Nodes and linkages. Nodes characterise data points in the network, which in the current study are authors. Linkages represent connections between nodes, which in the present analysis attest to the fact that two or more authors have co-authored a research paper and presented it at one of the EMAC conferences in the period 2000 to 2010 (Henneberg et al., 2009). The study at hand will use the terms node, actor, scholar, researcher and author interchangeably. The terms linkage, relationship, connection and co-authorship are also used interchangeably. In analysing social networks the number of linkages between actors characterises the interconnectedness of the network in addition to the idea of tie strength. This implies that if actor A has co-authored research with actor B and with actor C, then a linkage between actor A and actor B and a linkage between actor A and actor C exists. The strength of the ties between the actors can be assessed when looking at the number of research papers the actors have co-authored. If actor A has written three papers with actor B and only two papers with actor C, the strength (value) of the tie between actor A and actor B is stronger than that of actor A and actor C (Henneberg et al., 2009). 11 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 For the Social Network Analysis in question, the UCINET programme was used to conduct the analyses. The NetDraw programme was utilised to visualise the analyses performed in UCINET (Borgatti et al., 1999). 4.1 The Data Set The data source for the Social Network Analysis in the present study was retrieved manually from the European Marketing Academy conference proceedings 2000-2010. The study at hand limits its coverage to competing research papers presented at the conferences neglecting poster- and special sessions. Papers marked “withdrawn” in the 2010 conference proceeding were also excluded from the data set. Authors were identified by surname, which could lead to problems when names are inconsistent over time, when errors in the conference proceedings make distinguishing between first name and surname difficult or when two or more authors share the same surname. In order to avoid these problems a search was performed after entering each author name into the data set. If the search showed that a specific author name was already present in the data set, an inspection of the conference proceedings was done manually to investigate whether the specific author was already present in the data set. Authors sharing the same surname were given a code name so as to avoid confusion between individual authors (see Appendix 1 for list of code names). Through the aforementioned search and manual inspection of the conference proceedings inconsistencies in author name were also identified and corrected. Discrepancies in method of listing author names in the conference proceedings challenges the validity of the present study. In a number of the conference proceedings authors were listed by surname followed by first name, other proceedings listed authors by first name followed by surname and some applied a combination of the beforementioned methods. The method of searching the data set and manually inspecting the conference proceedings eliminated several of the discrepancies. In order to categorise the measures described below it is important to quantify the properties of the relationships under investigation. The relationships (linkages) in the EMAC data set are non-directional and valued. In a directional relationship the tie between two actors originates from a point and has a destination, i.e. the tie is directed 12 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 from one actor to the other. This property would be relevant if the study set out to measure for instance friendship. However, co-authorship between two authors does not have a direction so the relationship is non-directional. Dichotomous relationships are labeled as either present or absent for each set of actors. This type of relationship makes no attempt in measuring the strength of the relationship. The EMAC data set is valued as it is possible to measure the strength of the ties between actors in the network. This is done by observing the frequency of authors co-authoring research papers together. A high number of joint research papers will indicate a stronger tie between the actors (Wasserman and Faust, 1994; Henneberg et al., 2009). 4.2 Measures A number of social network measures are available for evaluating the characteristics of a collaboration network. As mentioned above, the linkages in the EMAC data set are non-directional and valued. These properties will influence the way in which a number of the measures in Social Network Analysis are defined. The following section will provide an introduction to the key term “components” and the measures will then each be considered in turn. 4.2.1 Components An important characteristic of a graph is whether it is connected or not. In order for a graph to be connected a path must exist between all pairs of nodes in the graph. This is, however, not always the case. Often a graph is partitioned into two or more subsets where no connection between the subsets exist. These subset are refered to as components. This means that all actors in a component can reach each other but they can not reach members of other components in the graph. The main component of a network is the component with the largest number of connected actors (Wassermann and Faust, 1994). Many analyses require that all the nodes are connected and it will therefore in many cases be relevant to extract the main component in order to perform the analysis on a fully connected network. 13 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 4.2.2 Connection and Distance 4.2.2.1 Density Density can be defined as “the ratio of the number of lines present to the maximum possible that could arise” (Wasserman and Faust, 1994: 143). In other words, the density of a network can tell how many of all possible ties are present in a network. This will in turn give insights into the speed at which information is diffused among members of the network and how cohesive the structure of the network is. A wellconnected network will be better at capitalising its resources and bringing forth a diverse range of perspectives for problem solving. The density of a network also provides insights into the role of the individual actors in a network. Some networks might be composed of quite similar actors while other networks can contain an elite of central actors with many ties and a larger group of actors with a small number of ties (Hanneman and Riddle, 2005). The variation in the degree of connectivity of actors in a network became evident in a number of studies as these saw the emergence of so-called “small worlds” and “invisible colleges” (Crane, 1972; Eaton et al., 1999; Newman, 2001b; Barabási et al., 2002; Moody, 2004; Morlacchi et al., 2005; Henneberg et al., 2009). 4.2.2.2 Geodesic Distance The geodesic distance of a network can be defined as “the length of the shortest path between two nodes” (Knoke and Yang, 2008: 60). The term is used to describe more complex characteristics of an individual´s position in the network and the structure of the network as a whole (Hanneman and Riddle, 2005). A problem arises when a network is not fully connected, here it is not possible to define the exact geodesic distance between all actors (Hanneman and Riddle, 2005). To overcome this problem the main component of the network can be extracted and the analysis can be performed on this specific part of the network. This will not yield a completely accurate result as the analysis is not performed on the cumulative data set, however, important properties of the individual actors and the structure of the main component will become evident. Previous research has shown that despite of a network growing over time, the geodesic distance between two actors actually decreases over time which supports the notion of networks forming “small worlds” (Barabási et al., 2002; Moody, 2004; Morlacchi et al., 2005). 14 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 4.2.2.3 Diameter The diameter of a connected graph can be defined as “the length of the largest geodesic distance between any pair of nodes” (Wasserman and Faust, 1994: 111). The term diameter gives information on the size of the network. It shows how many steps are necessary to get from one side of the network to the other side of it (Hanneman and Riddle, 2005). As with the geodesic distance, the diameter of a network can not be calculated accurately if the network is not fully connected. It is therefore necessary to extract the main component and then perform the analysis. If a network´s diameter is 5 or lower, it is said to exhibit “small world” properties (Henneberg et al., 2009). Earlier studies on co-authorship in a conference setting have shown that the main component of these research communities are not “small worlds”, on the contrary they display “large world” properties with diameters reaching 25 and 31 (Vidgen et al., 2007; Henneberg et al., 2009). 4.2.3 Centrality Measures The centrality measures in Social Network Analysis are primarily used to identify the most important actors in a social network. These measures seek to describe the location of central actors in networks as the most prominent actors often take up strategic positions within networks (Wasserman and Faust, 1994). 4.2.3.1 Actor Degree Centrality Actor degree centrality measures “the extent to which a node connects to all other nodes in a social network” (Knoke and Yang, 2008: 63). An actor who has a high degree centrality level takes up a hub position in the network as he/she will be in direct contact with or adjacent to many other actors. These central actors will be highly visible within the network and other actors will acknowledge their central location in the network as leading channels of relational information (Wasserman and Faust, 1994). With a larger number of connections, central actors have better opportunities for communcation because they have a greater selection of actors to communicate with. This means that central actors are less dependent on other individual actors and this gives them more social power within the network (Hanneman and Riddle, 2005). 15 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 4.2.3.2 Actor Closeness Centrality Actor closeness centrality indicates “how near a node is to the other nodes in a social network” (Knoke and Yang, 2008: 65), both directly and indirectly (Wasserman and Faust, 1994). This measure focuses on how close an individual actor is to the other actors in the network. It reflects the ability of an actor to access information through the network and the actor is central if he/she can communicate with all other members of the network rather quickly (Wasserman and Faust, 1994). An actor´s closeness centrality is a function of the shortest path between each individual (also known as the geodesic distance, see above) and every other person in the network (Knoke and Yang, 2008). The closeness centrality of an actor is inversely connected to distance which means that when nodes grow farther apart in distance from each other, its closeness centrality will decrease as the shortest path between members of the network becomes larger (Wasserman and Faust, 1994). Actors who are able to reach other actors at shorter path lengths enjoy a favourable position in the network. They serve as a reference point and their opinions are heard by a large number of actors, hence they have more social power within the network (Hanneman and Riddle, 2005). 4.2.3.3 Actor Betweenness Centrality Actor betweenness centrality relates “the extent to which other actors lie on the shortest path between pairs of actors in the network” (Knoke and Yang, 2008: 66). An actor will then be central if he/she lies on the geodesic distance between a large number of other actors. This measure takes into account the connectivity of the node´s neighbours and reflects the number of individuals an actor connects indirectly through their direct links (Wasserman and Faust, 1994). The central actors are in a position where they can influence the interactions between two nonadjacent actors as they can control the flow of information between other members of the network, this position naturally gives the actor more social power within the network (Hanneman and Riddle, 2005). The three actor centrality measures have been utilised extensively in the literature. Focusing on Social Network Analysis applied to a conference setting, several studies identified key researchers who dominated the centrality measures. These central actors play important hub roles in the networks which they are embedded in (Morlacchi et al., 2005; Vidgen et al., 2007; Henneberg et al., 2009). 16 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 4.2.3.4 Eigenvector Centrality The actor closeness centrality measure described above indicates how close actors are to each other in social networks. When dealing with larger and more complex networks, however, this measure can be slightly misleading. The closeness measure of two actors can assess the two actors as rather similar when in reality one actor is more central than the other because he/she is able to reach more of the network with the same amount of energy. Eigenvector centrality evaluates the importance of a node in a network in terms of the global structure of the network and therefore pays little attention to patterns that are more local. This is done in an effort to locate more central actors (Hanneman and Riddle, 2005). This means that if an actor has a high eigenvector centrality score he/she is connected to many other actors who in turn are also well-connected. Having a high eigenvector centrality score implies that the actor is more likely to receive ideas such as new research methods and hear of new terms and concepts within the collaboration network (Henneberg et al., 2009). 4.2.3.5 Flow Betweenness Centrality Flow betweenness centrality builds on the term actor betweenness centrality. Now and then the geodesic path between two actors may be blocked by a hesitant actor who is unwilling to pass on information between the two actors. A longer and less efficient pathway may exist between the two actors which they will make use of in order to bypass the reluctant actor. The flow betweenness centrality measure assumes that actors will use all pathways that connect them. It measures how involved an actor is in the flows between all other pairs of actors (Hanneman and Riddle, 2005). An additional quality of the flow betweenness centrality measure is that it considers the value of relations in a network, i.e. it separates weak ties from strong ties (Henneberg et al., 2009). According to Henneberg et al. (2009) flow betweenness centrality can be defined as “a measure of the extent to which the flow between other pairs of actors in the network would be reduced if a particular actor were removed” (Henneberg et al., 2009: 41). This means that the measure can be used to see what will happen to a collaboration network if a key researcher retires or otherwise leaves the network. 4.2.3.6 Reach Centrality Reach centrality can be defined as “the percentage of nodes in the network that the focal node can reach in a given number of steps” (Henneberg et al., 2009: 35). This measure 17 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 is another approach to identifying how close an actor is to other actors in a network. By asking what part of all other actors an actor can reach in one step, two steps, three steps etc. it can reveal how easily an actor can access information from other members of a network (Hanneman and Riddle, 2005). 4.2.4 Structural Holes The concept of structural holes implies that the less close knit a researcher´s co-authors are, the more a researcher connects researchers that are otherwise not connected (Morlacchi et al. 2005). Structural holes were first put forward by Burt (1992) who defined the concept as “the separation between nonredundant contacts. Nonredundant contacts are connected by a structural hole. A structural hole is a relationship of nonredundancy between two actors” (Burt, 1995: 18). The presence of structural holes may indicate a positional advantage or disadvantage for individuals embedded in a network. In occupying a nonredundant connection (a structural hole) an actor can play a key role in linking different parts of the network and thereby facilitate both the diffusion of new ideas, research methods, theories and concepts throughout the network, and the development of the network as a whole (Hanneman and Riddle, 2005; Morlacchi et al., 2005). In order for an actor to be effective, he/she must distinguish between primary and secondary contacts and then focus on maintaining relationships with the primary contacts, who serve as “ports of access to clusters of people beyond” (Burt, 1995: 21). By focusing on relationships with primary contacts, that is, those who provide access to new clusters, instead of relationships with contacts who copy access to already existing clusters (i.e. they are structurally equivalent, see more below) an actor can increase his/her power within the network (Vidgen et al., 2007). The presence of structural holes in networks has been demonstrated in a number of previous studies (Morlacchi et al., 2005; Vidgen et al., 2007). 4.2.5 Cohesive Subgroups Moving away from the way in which individual actors are connected, a macro perspective is adopted in order to focus on the social structures within which individual actors are embedded. Cohesive subgroups can be defined as “subsets of actors among whom there are relatively strong, direct, intense, frequent, or positive ties” (Wasserman and Faust, 1994: 249). In valued networks such as EMAC, a cohesive subgroup is one 18 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 where ties between actors have a high value. When evaluating cohesive subgroups a threshold value, c, is considered for the value of ties within the subgroup. The threshold, which ranges from 0 to c – 1, can be used to identify more or less cohesive subgroups (Wasserman and Faust, 1994). A disadvantage to actors in a network forming strong, cohesive subgroups is the risk of “groupthink” occurring within the network. In a collaboration network of scientific researchers, whose interest is to generate new knowledge and bring forth new research methods, terms and concepts, the occurrence of “groupthink” will limit the number of new ideas brought into the subgroup, and hence severely moderate the generation of new knowledge within the field of research (Granovetter, 1973; Wasserman and Faust, 1994; Vidgen et al., 2009). 4.2.5.1 Cliques A clique is a subgroup in a network where actors are more closely tied to one another than to other actors in the network. At level c a clique can be defined as “a subgraph in which the ties between all pairs of actors have values of c or greater, and there is no other actor outside the clique who also has ties of strength c or greater to all actors in the clique” (Wasserman and Faust, 1994: 278-279). Dividing a network into cliques of actors can yield important information on how a network as a whole is likely to behave. It can provide insights into where conflicts are likely to happen and if diffusion of new theories will run smoothely through the network (Hanneman and Riddle, 2005). The concept of cliques in Social Network Analysis has received criticism for being a rather strict method for identifying cohesive subgroups. This is because the absence of just one single tie can hinder a subgraph from being a clique (Knoke and Yang, 2008). 4.2.5.2 Structural Equivalence In order to make inferences about patterns of relations among actors in a network it can be useful to group together actors who are similar. This is done to predict social behaviour of actors and social structure of networks. In categorising actors into sets of actors who are equivalent it is possible to describe what makes these actors similar and what makes the specific category they belong to different from other categories of actors. The focus here is not the attributes of the individual actors but the similarities of the patterns of relations among these actors, which translates into the social role and the social position an actor can possess in a network (Hanneman and Riddle, 2005). 19 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Wasserman and Faust (1994) gives the following definition for structural equivalence in a valued network like EMAC: “For two actors to be structurally equivalent on a valued relation they must have ties with identical values to and from identical other actors” (Wasserman and Faust, 1994: 359). In other words, actors who are structurally equivalent hold identical positions in the structure of a social network. As with the term cliques described above, structural equivalence is defined rather strictly. The definition can be relaxed and it is then possible to measure how close two actors come to being perfectly structurally equivalent. The relaxed definition implies that “actors are approximately structurally equivalent if they have the same pattern of ties to and from other actors” (Wasserman and Faust, 1994: 360). 4.2.5.3 Cluster Analysis Cluster analysis divides actors into subgroups in which members are perfectly or approximately structurally equivalent and is used to see how closely knit researchers are within a given network. Three underlying criteria exist for establishing clusters: Single link, average link and complete link. In order to place actors in the same position (cluster) at a particular level of structural equivalence, a threshold value is decided upon which serves a boundary between clusters (Knoke and Yang, 2008). Complete link cluster analysis generates clusters where all pairs of actors are no less similar (no more different) than the threshold value decided upon. This type of cluster analysis outperforms alternative methods as it produces more homogeneous and stable clusters (Wasserman and Faust, 1994). Most actors take up positions in local neighbourhoods where the majority of actors are connected to each other, i.e. they are clustered into local neighbourhoods. This means that the density in local neighbourhoods of large networks have a tendency to be much higher than expected from random data of the same size (Hanneman and Riddle, 2005). Clustering within a network is expressed by it displaying “small world” properties. Several studies have reported this phenomenon (Watts and Strogatz 1998; Newman 2001b; Barabási et al., 2002; Moody, 2004; Morlacchi et al., 2005). 5. Results This section will present the results of the analyses. First, a number of basic characteristics of the cumulative network will be displayed. Second, the main 20 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 characteristics of connection and distance will be shown. Third, the main components of the individual years will be illustrated. Finally, the results of the more exhaustive analyses of the four years, which are the focus of the study at hand, will be presented. In the current study the distance measure geodesic distance will provide similar insights to the network as the density and the diameter. Consequently, this specific measure will not receive further attention. The measures concerning cohesive subgroups are not relevant to the approach of the study at hand as they will cover the same aspects as the centrality meaures and the division of the main components according to affiliation and track. They will therefore not be investigated further. 5.1 The EMAC Network The EMAC network is not fully connected. A number of components exist in the network for which no connection between authors in one component and authors in another component is present. This applies to both the cumulative network and the individual years. Year No. of actors in network No. of actors in main component 2000-2010 4043 2640 Table 1: Basic characteristics of the cumulative network 2000-2010. As shown in Table 1 above more than half of all actors in the EMAC network are in the main component indicating that researchers tend to collaborate across different disciplines and topics within the field of marketing. 5.2 Connection and Distance The table below presents some of the main characteristics of connection and distance for the EMAC conferences under investigation. 21 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 No. of Year Conference actors in No. of Density Diameter actors of of in main main main network component component component 2000 29th EMAC 342 17 0.0772 5 2001 30th EMAC 356 11 0.2000 4 2002 31st EMAC 532 15 0.4381 2 2003 32nd EMAC 427 13 0.1154 4 2004 33rd EMAC 622 25 0.2292 5 2005 34th EMAC 790 17 0.1213 4 2006 35th EMAC 859 25 0.0900 5 2007 36th EMAC 916 24 0.0797 4 2008 37th EMAC 763 15 0.1429 4 2009 38th EMAC 838 21 0.0738 6 2010 39th EMAC 893 37 0.0541 6 Table 2: Main characteristics of connection and distance for the EMAC conferences 2000-2010. Table 2 reveals a general increase in the number of actors in the network, i.e. in the number of researchers participating in the EMAC conferences 2000-2010 with coauthored papers. While the number of actors in the network has displayed a general increase, the density of the main components has fluctuated over the 11 year period. The density of a network is zero if no connection is present between any of the nodes in the network. On the other hand, if every single node is connected to every other node, the density is one (Henneberg et al., 2009). 2002 represents the year with the best connected network in the time period as 43.81 % of all possible ties are present. 2010 is the most sparsely connected network as only 5.41 % of all possible ties are present. The diameter provides information about how fast information is likely to diffuse throughout a network. The years 2000 to 2008 all have diameters of 5 or less, this means that these years display “small world” properties. On the other hand, the years 2009 and 2010 both have a diameter of 6 which points to less tightly knit networks. 22 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 5.3 Main Components 2000-2010 In the following the main components of 2000-2010 will be visualised. The number on each link in the diagrams represents the strength of the tie between two actors, i.e. the number of papers they have co-authored together. Figure 1: Main component for the EMAC Conference 2000. The main component for 2000 is presented in Figure 1. It reveals a somewhat scattered group of researchers grouped around Grønhaug and Hogg with Bruce occupying a hub role as he links two subgroups that would otherwise not be connected. The strength of the ties between the individual researchers shows that the actors in this specific main component has not co-authored more than one paper with each other. 23 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Figure 2: Main component for the EMAC Conference 2001. Figure 2 illustrates the main component for 2001. It is slightly more dense than that of 2000 and identifies De Wulf and Odekerken-Schröder as the researchers who the component is grouped around. Van Kenhove and De Wulf hold hub positions and link two subgroups to the main component that would otherwise be disconnected. The majority of the researchers in this specific main component have only co-authored one research paper with each other, however, De Wulf and Odekerken-Schröder have coauthored three papers together. Figure 3: Main component for the EMAC Conference 2002. 24 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 The main component for year 2002 is shown in Figure 3 above. It displays a solid network with a cohesive and robust structure. Blesa represents an outlier as this specific researcher has only co-authored with one of the actors in the network. Each member has only written one research paper with every actor he/she is connected to. Figure 4: Main component for the EMAC Conference 2003. Figure 4 displays the main component for 2003. It reveals a sparsely connected network where De Valck takes up a hub role as this specific researcher links the two parts of the component. Again the number of research papers the members of this component has produced with actors they are connected to equals one. 25 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Figure 5: Main component for the EMAC Conference 2004. It can be seen in Figure 5 that the main component for 2004 is rather dense indicating a well connected network with a robust structure. The general trend of not co-authoring more than one research paper with other actors continues for the main component for 2004. Hooley, Greenley and Möller, however, have all co-authored two research papers and serve as the links between two groups in the component that would otherwise not be connected. Figure 6 below shows the main component for 2005. It reveals a somewhat compact network grouped around Wetzels and De Ruyter, with Wetzels occupying a hub position as he links two otherwise disconnected parts of the component. This main component differs from the main components of previous years as some actors have coauthored several research papers together. Again Wetzels and De Ruyter stand out as they have co-authored four papers together. De Ruyter has, additionally, co-authored two papers with Schepers. 26 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Figure 6: Main component for the EMAC Conference 2005. Figure 7: Main component for the EMAC Conference 2006. 27 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Figure 8: Main component for the EMAC Conference 2007. Figure 7 above illustrates the main component for 2006. It presents a rather cohesive network with a compact center. Möller and Bloemer hold hub positions in the component as they join two parts of the network to the center of the component that, if they were not present, would be disconnected from the main component. The majority of the tie strengths are one following the trend of earlier years. Möller and Matear have, however, co-authored two research papers together and Matear has, additionally written two papers with Hooley. The main component for 2007 is displayed in Figure 8 above. It identifies two groups of researchers linked by the collaboration of Wetzels and Stokburger-Sauer. Again the majority of the tie strengths are one following the trend exhibited in previous years. Three sets of actors, however, have collaborated on two research papers. These are: Stokburger-Sauer and Bauer; Lages and Queiroga; and Wetzels and Van Birgelen. 28 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Figure 9: Main component for the EMAC Conference 2008. Figure 9 above shows the main component for 2008. It presents a somewhat cohesive network where Herrmanan and Tomczak act as hubs in connecting the groups of the component. Once again the majority of the strength of the ties in the network are equal to one, except the tie linking Tomczak and Mühlmeier who have collaborated twice in 2008. Representing the main component for 2009 is Figure 10 below. It reveals a network which to some degree is scattered. The collaboration between Völckner, Becker and Ringle links a small group of researchers to the larger part of the network. Furthermore, the collaboration between Brito and Carvalho connects another small group of actors to the more compact part of the network. All actors in 2009 have only co-authored one research paper with other actors to whom they are connected and all tie strengths are therefore equal to one. 29 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Figure 10: Main component for the EMAC Conference 2009. Figure 11: Main component for the EMAC Conference 2010. Figure 11 above presents the main component for the final year of analysis, namely 2010. It reveals a relatively cohesive network with a comparatively robust structure. Sattler and Hennig-Thurau serve as hubs as they link two relatively large groups to the 30 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 more compact part of the network. As in the previous years the majority of the tie strengths are one, except the tie between Erfgen and Sattler, and the tie between Sattler and Völckner which both equal two. 5.4 EMAC Conference 2001 In the current section the results of the more detailed analysis of the EMAC conference of 2001 will be presented. 5.4.1 Affiliation and Track Affiliation key: Ghent University, Belgium Maastricht University, The Netherlands Figure 12: Main component for 2001 with affiliation. Figure 12 above illustrates the main component for 2001 according to affiliation. It can be seen that the vast majority of the researchers are affiliated with Ghent University in Beligium pointing to strong geographical clustering within the main component for 2001. Further analysis of the main component for 2001 revealed that although the researchers are affiliated with the same university the tracks (see Appendix 2 for list of tracks) within which they co-author scientific research papers are diverse. This is demonstrated in Figure 13 below. When examining Figure 13 it becomes evident that 31 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 some researchers tend to work across tracks within the field of marketing. Especially De Wulf and Odekerken-Schröder distinguish themselves as they have co-authored within four and three tracks, respectively. The network, however, does not exhibit track-based clustering as each actor has only co-authored one scientific research paper within each track. Track key: Relationship Marketing Consumer Behaviour Retailing, Channel Management and Logistics Advertising, Promotion and Marketing Communication New Technologies and E-Marketing Figure 13: Main component for 2001 according to track. 5.4.2 Central Actors The three most central actors in the main component were selected for further analysis by assessing the neighbourhood size of all actors in the main component. Henneberg et al. (2009) refer to neighbourhood size as the number of other actors with whom an actor has links. The three actors with the largest neighbourhood were then chosen. 32 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 According to Table 3 below, De Wulf is the most active researcher in the main component for 2001. Actor degree centrality identifies De Wulf as a highly visible actor within the network. This is also reflected in the actor closeness centrality measure, which characterises De Wulf as the researcher who is closest to other actors in the component. The actor betweenness centrality measure takes into account the indirect ties of an actor. It reveals De Wulf and Van Kenhove to be the leaders in the network as they hold the highest score on this specific measure. These findings correspond to the diagram in Figure 2 in which De Wulf and Van Kenhove are characterised as a central actors. Actor Actor Actor Actor Neighbourhood degree closeness betweenness size centrality centrality centrality De Wulf 7 8 76.923 Van Kenhove 6 6 71.429 Odekerken-Schröder 5 6 66.667 Table 3: Actor centrality measures for the main component of 2001. 21 21 5 Table 4 below provides additional centrality measures for the main component of 2001. The eigenvector centrality measure locates De Wulf to be a central actor within the network as this actor is connected to many other actors who, in turn, are also well connected. A somewhat surprising finding is that Odekerken-Schröder has a higher score than Van Kenhove in this measure. However, when examining Figure 2 it becomes evident that the connections of Odekerken-Schröder are better connected than the actors which Van Kenhove is connected to, hence the higher eigenvector centrality. De Wulf also holds the highest score on the flow betweenness centrality measure. This means that the flow in the main component of 2001 would be creatly reduced if this specific researcher were to leave the network. Van Kenhove is also identified as an actor with high flow betweenness centrality score. Again an examination of Figure 2 justifies this high value as it can be seen that Van Kenhove holds a hub position in the network. The reach centrality measure indicates that the main component for 2001 is rather dense as all three central researchers can reach the entire network in two steps. Finally, the concept of structural holes shows the degree to which a researcher connects researchers that are otherwise not connected. Again De Wulf and Van Kenhove hold high values as they occupy hub positions in the network. This is also demontrated in 33 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Figure 2 where De Wulf links two researchers to the more compact group of researchers and Van Kenhove connects three researchers to the group. Flow Reach centrality Eigenvector betweenness Structural centrality centrality two-step three-step hole Actor De Wulf 75.217 47.667 1.00 Van Kenhove 52.360 47.000 1.00 Odekerken-Schröder 69.095 14.667 1.00 Table 4: Additional centrality measures for the main component of 2001. 1.00 1.00 1.00 5.000 4.167 2.667 5.4.3 Additional Component Analysis The following results refer to the cumulative network for 2001. Table 5 below shows the main component together with the second and third largest components in the cumulative network for 2001. The density of the components are relatively high indicating a comparatively well connected network. This is also reflected in the diameter of the components. As none of the diameters exceed 5, they all display “small world” properties. Component No. of actors Density Diameter 1 11 0.2000 4 2 10 0.1556 3 3 7 0.2679 2 Table 5: Main co-authorship component characteristics for 2001. 34 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Figure 14 below illustrates the second largest component of 2001 according to affiliation. The component reveals a relatively strong geographical clustering around Kingston Business School, England. Affiliation key: Kingston Business School, England Casio Electronics Ltd. University of South Australia, Australia Massey University, New Zealand London Business School, England Figure 14: Second component for 2001 with affiliation. 35 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Additional analysis of the second largest component of 2001 shows a minor tendency towards track-based clustering around East. East is the most active researcher within this component, having co-authored two papers in one track and one in another track. These findings are presented in Figure 15 below. Track key: Product and Brand Management Modeling and Forecasting Consumer Behaviour Retailing, Channel Management and Logistics Figure 15: Second component for 2001 according to track. 36 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 The third component for 2001 with affiliation is displayed in Figure 16 below. It reveals very strong geographical clustering as all members of the component are affiliated with the same institution, namely Athens University of Economics and Business, Greece Affiliation key: Athens University of Economics and Business, Greece Figure 16: Third component for 2001 with affiliation. 37 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Track key: Marketing Strategy and Leadership Retailing, Channel Management and Logistics Consumer Behaviour Service Marketing Figure 17: Third component for 2001 according to track. Figure 17 above, shows the third component for 2001 according to track. The network does not exhibit track-based clustering as each individual author has only co-authored one scientific research paper within each track. Papastathopoulou is the most active node in the component as this specific researcher has collaborated on papers in all four tracks represented in the component. 5.5 EMAC Conference 2004 In this section the more exhaustive analysis of the EMAC conference of 2004 will be presented. 38 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 5.5.1 Affiliation and Track Affiliation key: Helsinki School of Economics, Finland Aston University, England Budapest University of Economic Science and Public Administration, Hungary Monash University, Australia University of Limerick, Ireland Univerza V Mariboru, Slovenia City University of Hong Kong Wielkopolska Business School – Poznañ University, Poland ALBA – Athens Laboratory of Business Administration, Greece University of Innsbruck, Germany Cardiff University, Cardiff Business School, Wales University of Wales Aberystwyth, School of Management and Business, Wales Stern School, NYU, USA Maastricht University, The Netherlands University of Otago, New Zealand 39 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 University of Helsinki, Finland Loughborough University, England Figure 18: Main component for 2004 with affiliation. The main component for 2004 according to affiliation is displayed in Figure 18 above. It can be seen that a large number of universities and business schools are represented in the diagram. This indicates very little geographical clustering within the component. Additional analysis of the main component for 2004 revealed extremely strong trackbased clustering. This is illustrated in Figure 19 below. This result, however, is not surprising since the majority of the researchers in the main component have collaborated on one scientific research paper. Figure 19: Main component for 2004 according to track. 5.5.2 Central Actors As can be seen in Table 6 below Greenley, Hooley and Möller have been identified as the actors in the main component of 2004 who have the largest neighbourhood. In fact, for all measures Greenley, Hooley and Möller have the same score. This means that the three actors hold identical positions in the network. These finding are reflected in Figure 5 above. 40 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Actor Actor Actor Actor Neighbourhood degree closeness betweenness size centrality centrality centrality Greenley 19 19 82.759 Hooley 19 19 82.759 Möller 19 19 82.759 Table 6: Actor centrality measures for the main component of 2004. Actor 24 24 24 Flow Reach centrality Eigenvector betweenness Structural centrality centrality two-step three-step hole Greenley 36.752 24 1.00 Hooley 36.752 24 1.00 Möller 36.752 24 1.00 Table 7: Additional centrality measures for the main component of 2004. 1.00 1.00 1.00 6.474 6.474 6.474 5.5.3 Additional Component Analysis The succeeding results refer to the cumulative network for 2004. Table 8 below displays the main component together with the second and third largest components in the cumulative network for 2004. While the density of the main component is comparatively high indicating a somewhat well connected network, the two smaller components´ densities are low. This means that the two smaller components are not very compact and their structures are not very robust. The diameter of the components, however, show that all three components display “small world” properties. Component No. of actors Density Diameter 1 25 0.2292 5 2 18 0.0948 4 3 15 0.1000 2 Table 8: Main co-authorship component characteristics for 2004. 41 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Affiliation key: University of Maastricht, The Netherlands University of Nijmegen, The Netherlands University of Antwerp, Belgium University of California, USA Eindhoven University of Technology, The Netherlands Portland State University, USA Free University, Germany Figure 20: Second component for 2004 with affiliation. Figure 20 above displays the second component for 2004 with affiliation. It demonstrates geographical clustering around the University of Maastricht, The Netherlands, Eindhoven University of Technology, The Netherlands and the University of Antwerp, Belgium, respectively. Three individual researchers from the University of Maastricht stand out as they each are disconnected from any other researchers from that institution. 42 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Track key: Service Marketing Consumer Behaviour Relationship Marketing Innovation and New Product Development New Technologies and E-Marketing Figure 21: Second component for 2004 according to track. The second component for 2004 according to track (Figure 21 above), illustrates trackbased clustering around Bloemer and especially Wetzels. De Ruyter is the most active node as this specific author has collaborated on four different research papers within three different tracks. 43 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Affiliation key: University of Nottingham, England University of Glasgow, Scotland University of East Anglia, England Open University of Hong Kong University of Strathclyde, Scotland Cardiff Business School, Wales Figure 22: Third component for 2004 with affiliation. Figure 22 above shows that the third component for 2004 with affiliation exhibits geographical clustering around the University of Nottingham, England and the University og Glasgow, Scotland, respectively. 44 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Track key: International and Cross-Cultural Marketing Modeling and Forecasting Relationship Marketing Business-to-Business Marketing and Networks New Technologies and E-Marketing Consumer Behaviour Marketing Strategy and Leadership Figure 23: Third component for 2004 according to track. The third component for 2004 acccording to track is presented in Figure 23 above. It reveals no track-based clustering. It does, however, identify Ennew as the most productive node with four different research papers written in four different tracks. 5.6 EMAC Conference 2007 In the section at hand the more thorough analysis of the EMAC conference of 2007 will be presented. 45 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 5.6.1 Affiliation and Track Affiliation key: University of Mannheim, Germany University of Maastricht, The Netherlands Eindhoven University of Technology, The Netherlands New University of Lisbon, Portugal Instituto Superior de Ciencias do Trabalho e da Empresa, Portugal Nijmegen School of Management, The Netherlands University of Innsbruck, Germany University of Antwerp, Belgium No affiliation available Figure 24: Main component for 2007 with affiliation. The main component for 2007 according to affiliation is displayed in Figure 24 above. It shows a large group of researchers to be affiliated with the University of Mannheim in Germany. In addition to this, two smaller groups of researchers are affiliated with two Dutch universities, namely the University of Maastricht and Eindhoven University of Technology, respectively. This points to some geographical clustering within the network. Additional analysis of the main component for 2007 revealed that although some of the researchers are affiliated with the same university, they have co-authored 46 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 scientific research papers within a number of different tracks in the field of marketing. This is illustrated in Figure 25 below. Stokburger-Sauer and Bauer have collaborated on two different research papers within two different tracks, the same has Van Birgelen and Wetzels. Wetzels, however, has co-authored two different research papers within the same track, pointing to minor track-based clustering. Track key: New Technologies and E-Marketing Marketing of Public and Non-Proft Organisations Service Marketing International and Cross-Cultural Marketing Marketing Strategy and Leadership Business-to-Business Marketing and Networks Tourism Marketing Social Responsibility, Ethics and Consumer Protection Advertising, Promotion and Marketing Communication Figure 25: Main component for 2007 according to track. 5.6.2 Central Actors The most active researcher in the main component for 2007 is, as can be seen in Table 9 below, Wetzels. He is the best connected researcher in the network as reflected in his 47 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 actor degree centrality score and repeated in his actor closeness centrality score. The actor betweenness centrality measure reveals that Wetzels also has the highest number of indirect connections through his direct links in the network. These findings are in accordance with the diagram in Figure 8, which also identifies Wetzels as the main actor in 2007. Actor Actor Actor Actor Neighbourhood degree closeness betweenness size centrality centrality centrality Wetzels 11 11 54.762 Bauer 8 9 42.593 Lageslu 7 7 41.818 Table 9: Actor centrality measures for the main component of 2007. 181.500 110.500 62.000 Table 10 below shows additional centrality measures for the main component of 2007. Oddly enough, all the eigenvector centrality scores for 2007 were negative. Everett (2001) found a similar result and gave the explanation that the negative results were due to the network containing disconnected components. He used the absolute value of the scores instead. Following Everett (2001), the absolute value of the eigenvector centrality score will be used in interpreting the findings. This then locates Wetzels as the actor with the most well connected connections. He also holds the highest flow betweenness centrality score and it would therefore reduce the flow in the network if he was to leave the network. The reach centrality measure points to a less dense network as the most central actor, Wetzels, can only reach 74 % percent of the component in two steps. Finally, the concept of structural holes reveals Wetzels to be the researcher who links researchers that would otherwise be disconnected. These findings can also be seen in Figure 8. Actor Flow Reach centrality Eigenvector betweenness Structural centrality centrality two-step three-step hole Wetzels - 73.648 370.000 0.74 Bauer - 27.323 226.000 0.43 Lageslu - 50.084 128.000 0.61 Table 10: Additional centrality measures for the main component of 2007. 0.96 0.87 0.74 9.000 6.556 5.000 48 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 5.6.3 Additional Component Analysis The following results refer to the cumulative network for 2007. Table 11 below reveals the main component together with the second and third largest components in the cumulative network for 2007. The density of the components are relatively small indicating a sparsely connected network. The diameter of the components, however, show that all three components display “small world” properties. Component No. of actors Density Diameter 1 24 0.0797 4 2 19 0.0965 5 3 14 0.1264 3 Table 11: Main co-authorship component characteristics for 2007. Affiliation key: Delft University of Technology, The Netherlands University of Wollongong, Australia Erasmus University, The Netherlands Wirtschaftsuniversität, Wien, Austria McMaster University, Canada Graz University, Austria 49 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Concordia University, Montreal, Canada Bishop´s University, Canada No affiliation available Figure 26: Second component for 2007 with affiliation. Figure 26 above illustrates the second component for 2007 according to affiliation. It reveals geographical clustering around Delft University of Technology, The Netherlands and the University of Wollongong, Australia. Track key: Innovation and New Product Development Advertising, Promotion and Marketing Communication Product and Brand Management Marketing Research and Research Methodology Marketing of Public and Non-Profit Organisations Figure 27: Second component for 2007 according to track. The second component for 2007 according to track is displayed in Figure 27 above. The component exhibits relatively strong track-based clustering with six papers being co- 50 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 authored within the same track. Minor track-based clustering also appears around El Houssi. Affiliation key: University of Groningen, The Netherlands Erasmus University, The Netherlands Waikato Management School, New Zealand TNO –Netherlands Organisation for Applied Scientific Research, The Netherlands VU University of Amsterdam, The Netherlands Tilburg University, The Netherlands Delft University of Technology, The Netherlands No affiliation available Figure 28: Third component for 2007 with affiliation. Figure 28 above presents the third component for 2007 according to affiliation. The figure demonstrates geographical clustering around the University of Groningen, The Netherlands. 51 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Track key: New Technologies and E-Marketing Marketing Research and Research Methodology Relationship Marketing Consumer Behaviour Innovation and New Product Development International and Cross-Cultural Marketing Figure 29: Third component for 2007 according to track. The third component for 2007 according to track is presented in Figure 29 above. The component only displays minor track-based clustering around Huizingh. The most active node in the component is Bijmolt, who has co-authored six research papers in six different tracks. 5.7 EMAC Conference 2010 In the current section the results of the more detailed analysis of the EMAC conference of 2010 will be presented. 52 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 5.7.1 Affiliation and Track Affiliation key: University of Hamburg, Germany University of Cologne, Germany University of Innsbruck, Germany Erasmus University Rotterdam, The Netherlands Waikato Management School, New Zealand Groningen University, The Netherlands University of Munich, Germany University of St. Gallen, Switzerland Bauhaus University of Weimar, Germany Figure 30: Main component for 2010 with affiliation. Figure 30 above shows the main component for 2010 according to affiliation. The diagram reveals three large groups of researchers to be affiliated with the University of Hamburg, the University of Cologne and the University of Innsbruck, respectively. Additionally, a small group of researchers from the University of Hamburg is disconnected from the larger group of researchers from this specific university but connected to the group through Völckner, who herself is affiliated with the University of Cologne. These findings indicate strong geographical clustering within the network. 53 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Further analysis of the main component for 2010 showed a moderate tendency towards track-based clustering grouped around Sattler and Völckner. This is demonstrated in Figure 31 below. Sattler has co-authored two research papers in each of two different tracks. Völckner, in particular, has been very active collaborating in three different tracks with a total of six scientific research papers. Track key: Advertising, Promotion and Marketing Communication Consumer Behaviour Innovation and New Product Development Product and Brand Management Service Marketing International and Cross-Cultural Marketing Marketing Research and Research Methodology Marketing Theory Marketing of Public and Non-Profit Organisations Figure 31: Main component for 2010 according to track. 54 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 5.7.2 Central Actors According to Table 12 below, Völckner is the most active researcher in the main component for 2010. The actor degree centrality measure score of Völckner reflects a high degree of direct contact with many other actors in the network. She also serves as the actor who is closest to other actors in the network, which is demonstrated by the relatively high actor closeness centrality score. The actor betweenness centrality measure supports the results of the two former as it identifies Völckner as the leading researcher in the network. These findings are reflected in the diagram in Figure 11, in which it can be seen, that Völckner holds a central position in the network. Actor Actor Actor Actor Neighbourhood degree closeness betweenness size centrality centrality centrality Völckner 16 17 47.368 Sattler 8 10 37.500 Matzler 7 7 24.490 Table 12: Actor centrality measures for the main component of 2010. 447.000 158.500 99.000 Table 13 below displays additional centrality measures for the main component of 2010. Not surprisingly, Völckner has the highest eigenvector centrality score as she is connected to many other actors who are also well connected (see Figure 11). Matzler´s eigenvector centrality score, however, is low. The reason for this can be seen in Figure 11. It shows Matzler to be connected to a group of researchers, who are only connected to the rest of the component through one researcher. The flow betweenness centrality measure supports what can be seen in Figure 11, namely that if Völckner decides to leave the network it would leave it scattered. The reach centrality measure indicates a less dense network as the most central actor can only reach 72 % percent of the component in two steps. The structural hole measure confirms what the other measures have demonstrated, that Völckner occupy a hub position in the network. 55 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Actor Flow Reach centrality Eigenvector betweenness Structural centrality centrality two-step three-step hole Völckner 79.036 913.000 0.72 Sattler 58.989 360.333 0.64 Matzler 0.551 203.000 0.25 Table 13: Additional centrality measures for the main component of 2010. 0.81 0.75 0.31 13.912 6.100 4.429 5.7.3 Additional Component Analysis The following results refer to the cumulative network for 2010. The main component together with the second and third largest components in the cumulative network for 2010 is presented in Table 14 below. The density of the components are relatively low indicating a sparsely connected network. This is also reflected in the diameter of the main component as it is above the threshold value for exhibiting “small world” properties. The diameters for the second and third largest components for 2010 do indeed, however, diplay “small world” properties. Component No. of actors Density Diameter 1 37 0.0541 6 2 24 0.0833 3 3 15 0.0952 2 Table 14: Main co-authorship component characteristics for 2010. 56 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Affiliation key: Ghent University, Belgium Catholic University of Leuven, Belgium University of Vienna, Austria Vlerick Leuven Gent Management School, Belgium University of Bern, Switzerland Richard Ivey School of Business, Canada Figure 32: Second component for 2010 with affiliation. Component number two according to affiliation is presented in Figure 32 above. A relatively strong geographical clustering around Ghent University, Belgium becomes evident when examining the diagram. The figure also reveals minor geographical clustering around the Catholic University of Leuven, Belgium. 57 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Track key: Consumer Behaviour Innovation and New Product Development Product and Brand Management Marketing Research and Research Methodology Retailing, Channel Management and Logistics Advertising, Promotion and Marketing Communication International and Cross-Cultural Marketing Figure 33: Second component for 2010 according to track. Figure 33 above illustrates component number two according to track for 2010. It reveals strong track-based clustering around Vermeir, in particular. This specific actor is also the most productive member of the component with seven different research papers written in three different tracks. 58 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Affiliation key: University of Murcia, Spian Catholic University of Leuven, Belgium BI – Norwegian School of Management, Norway Autonomous University Madrid, Spain Koc University, Turkey Figure 34: Third component for 2010 with affiliation. Component number three for 2010 according to affiliation is displayed above in Figure 34. It presents geographical clustering around the University of Murcia, Spain. Additionally, minor clustering appears around the Catholic University of Leuven, Belgium and the Norwegian School of Management, Norway. 59 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Track key: Consumer Behaviour Advertising, Promotion and Marketing Communication New Technologies and E- Marketing Social Responsibility, Ethics and Consumer Protection Figure 35: Third component for 2010 according to track. The final component to be displayed is the third component for 2010 according to track (Figure 35). It shows relatively strong track-based clustering around Warlop within the track Consumer Behaviour. Furthermore, clustering appears in the track Advertising, Promotion and Marketing Communication. The most active node in the network is Ruizsa, who has collaborated on four different research papers in three different tracks. 6. Discussion of Results The following sections will discuss the findings presented above. The first section will discuss the development of the EMAC network from 200 to 2010 and visualise findings from Table 2. The four succeeding sections will then discuss the findings of the analysis of the years 2001, 2004, 2007 and 2010 individually. 60 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 6.1 Development of the EMAC Network 2000-2010 In reviewing the literature, several studies revealed research communities that were not fully connected as the networks were comprised of a number of subgroups not connected to each other by paths between authors (Vidgen et al., 2007; Henneberg et al., 2009). These results are in line with the findings of the study at hand, which also observed a number of components without links between them - a result that applied to both the cumulative network and the individual years. This can, in part, be ascribed to researchers collaborating on scientific research papers by preferential attachment, close geographical or cultural proximity, or similar field of interest in research. For the cumulative network (i.e. 2000-2010) more than half of all actors are in the main component. This corroborates the findings of previous studies on co-authorship (Newman, 2001a; Liu et al., 2005; Henneberg et al. 2009). This result points to a tendency for some authors to work across different tracks and topics in the field of marketing. 1000 No. of actors in network 900 800 700 600 500 400 300 200 100 0 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 Year Figure 36: The development in the number of actors in the EMAC network 2000-2010. The development in the number of actors in the EMAC network 2000-2010 is visualised in Figure 36 above. It reveals a general increase in the number of researchers who have participated in the EMAC conferences with one or more co-authored research papers. This finding is consistent with the results of Laband and Tollison (2000) and Moody (2004) who observed an increase in co-authorship in a number of scientific disciplines. A possible explanation for the increase in researchers co-authoring in the EMAC 61 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 community could be an increased degree of specialisation. When examining the main components according to track in three of the four years which are the focus of the current study, a tendency towards specialisation becomes evident. The figures reveal that the central authors tend to change collaboration partners according to the topic of the research paper. Interviews with central actors in the network would provide information on the degree to which researchers in the EMAC community tend to specialise. A strong relationship between the measures density and diameter and the concept of “small worlds” has been reported in the literature (Newman, 2001b; Barabási et al., 2002; Morlacchi et al., 2005; Vidgen et al., 2007). The findings of the study at hand lends support to this relationship. Figure 37 below illustrates the development in the density of the main components in the period 2000 to 2010. It shows that the density is generally rather low with the exception of the year 2002 and to some extent 2004. This points to the networks not exhibiting “small world” characteristics. These generally low scores indicate that the networks of the individual EMAC conferences are somewhat sparsely connected. A closer inspection of Table 2 reveals the reason behind this result. The individual years which have the highest number of participating actors display the lowest density score. This result is in agreement with the findings of Vidgen et al. (2007) and Henneberg et al. (2009), which demonstrated an asymptotic convergence of density towards 0.0 as the number of actors in the network increased. The comparatively low scores in the current network means that information does not travel very fast within the network, i.e. new research methods, theories and concepts are not easily diffused in the network of the individual years. 62 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 0,5 0,45 0,4 Density 0,35 0,3 0,25 0,2 0,15 0,1 0,05 0 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 Year Figure 37: The development in density of the main components 2000-2010. The development in the diameter of the main components in the period 2000 to 2010 is visualised in Figure 38 below. Despite the relatively low density scores, the majority of the individual years, with the exception of 2009 and 2010, display “small world” properties as their diameters are 5 or lower. Figures 1 to 11 demonstrate the majority of years to have networks which are grouped around central researchers who collaborate extensively within the network and play a crucial role in linking various parts of the network, i.e. they display “small world” properties. These findings are in accordance with results presented by Newman (2001b), Barabási et al. (2002) and Morlacchi et al. (2005) as they found the typical distance between researchers within networks to be small. However, the findings of the study at hand do not support previous research on co-authorship in a conference setting. On the contrary, Vidgen et al. (2007) and Henneberg et al. (2009) found that the main components of the collaboration networks under their investigation displayed “large world” properties. These contradicting results may be explained by the fact that these two studies were based on cumulative data whereas the current study focuses on the main components of the individual years. The fact that the majority of the individual years exhibit “small world” characteristics points to a relatively easy diffusion of new theories, concepts and research methods within the network. 63 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 7 6 Diameter 5 4 3 2 1 0 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 Year Figure 38: The development in diameter of the main components 2000-2010. Prior studies have noted the presence of so-called “invisible colleges” within social networks (Crane, 1972; Eaton et al., 1999; Morlacchi et al., 2005; Henneberg et al., 2009). The study at hand produced results which corroborate the findings of previous work in this field. “Invisible colleges” formed by highly productive and central actors take up hub positions in the main components of the current study. These researchers hold key roles in disseminating knowledge throughout the network as they reoccur as central players in a number of years. An example of an “invisible college” within the EMAC community is a group of ten researchers (Anttila, Matear, Hooley, Theoharakis, Greenley, Tuominen, Hyvönen, Möller, Rajala and Kasper), who are all members of the compact main component in the year 2004. These actors reoccur in 2006 where they form the core of the main component for that year. This finding indicates continuous collaboration over time, hence supporting the notion of “invisible colleges” within the EMAC community. 6.2 EMAC Conference 2001 The present study was designed to determine the structure of EMAC´s collaboration network and the way in which researchers in the EMAC community work together to generate knowledge. The most interesting result from the year 2001 was that the main component displayed strong geographical clustering around in particular, Ghent 64 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 University, Belgium and Maastricht University, The Netherlands. A possible explanation for this might be preferential attachment as some actors might prefer to collaborate with actors of close geographical and cultural proximity to themselves. This could be due to the fact that it might be easier to work with colleagues from the same workplace that speak the same language. Another possible explanation could be that this group of researchers interact socially and have developed friendships which in turn has developed into professional working relationships. The results of the current study supports the findings of previous research which found a tendency for geographical groupings within networks (Liu et al., 2005; Morlacchi et al., 2005). Another interesting result is the way in which the actors in the main component are divided according to track. The authors in this specific main component work across a diverse set of tracks. However, the network does not display track-based clustering as each individual actor has only co-authored one research paper in each track. A possible explanation for the lack of track-based clustering could be the fact that the main component for 2001 is extremely small. A higher number of actors in the main component would lead to a greater possibility of actors working across more than one track. It is interesting to note that the most well connected actor in the main component holds the highest score on all the centrality measures. This identifies De Wulf as the most prominent researcher in the main component for 2001 as this researcher takes up a strategically important position within the network. It suggests that De Wulf is the most popular collaboration partner and other actors will then more likely acknowledge the central location in the network of this researcher as a leading channel of relational information. With a high score on all the centrality measures De Wulf is very likely to be the researcher to hear of new research methods, theories, terms and concepts first as this actor is well connected. This actor can thereby influence the flow of information in the network. Frequently published actors like De Wulf seem to be generators of stucture within the network. The collaborations of these actors create the links that shed light on the institutional, intellectual and social structure of the EMAC community. An additional observation from the diagrams in Figure 12 and Figure 13 is that the more productive authors tend to collaborate more and to collaborate across tracks. The three 65 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 central actors in the main component have all worked on more than one track. This observation could lend support to the tendency towards specialisation as it appears that the central actors bring in specialists when working on different tracks. However, more research on this topic needs to be undertaken before the association between the way in which productive actors collaborate across tracks and specialisation is more clearly understood. Classical network models work under the assumption of complete randomness, i.e. the actors are connected to each other independently of the number of links they already have (Watts, 1999). However, the findings of the study at hand do not support this assumption. The main component for 2001 revealed itself to be highly clustered around a few individual researchers and the network is therefore not characterised by a random set of connections. The central actors of the network serve as centers from which knowledge (and possibly also research strategy) is pushed out. The structure of the main component of 2001 does therefore not reflect a random process but rather an intentional form of research collaboration. Additional analysis of the second and third largest component in the cumulative network for 2001 provided further support for the suggestion that members of the EMAC community tend to work with authors of close geographical and cultural proximity. The second component revealed relatively strong clustering while component three exhibited very strong clustering with all members being affiliated with the same institution. The findings of the additional component analysis also supply support for the results of the analysis of the main component with regards to trackbased clustering. The second component demonstrated only minor clustering while the third component displayed none. These findings indicate a tendency for choosing collaboration partners based on geographical and cultural proximity for the network of 2001. 6.3 EMAC Conference 2004 In contrast to the findings for the year 2001, the results for the year 2004 showed very limited geographical clustering in the main component. Helsinki School of Economics in Finland is the most well represented institution with four affiliated researchers. This 66 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 finding is somewhat surprising when compared to the results from 2001. A possible explanation for this, however, emerges when inspecting Figure 19, which displays the main component according to track. It reveals very strong track-based clustering as all members of the main component have collaborated within one single track. This indicates that members of the main component choose collaboration partners based on their field of interest, i.e. the track. Caution should be taken with this result, however. As the main component is comprised mainly of authors collaborating on just one research paper it is difficult to make general statements about the behaviour of this group of actors based on the findings from this component. At first glance the results presented for the centrality measures for the three most central actors are surprising as they are identical. Closer inspection of Figure 19 and the conference proceeding for 2004, however, shows that these actors have identical collaboration partners and have co-authored the same research papers. In doing so they hold identical positions in the network. More researchers would turn out to hold equivalent positions in the network if the list of central actors was expanded. This is due to the fact that the majority of the actors in the main component for 2004 have coauthored one research paper together. Further research should be done to investigate the motivation behind this large number of actors collaborating on this specific research paper. This could be done in the form of interviews. Figure 18 and 19 do not provide support for the connection between author productivity and collaboration. As the main component of 2004 has proven to be quite extraordinary, it will be relevant at this point to include the second and third component to discover if the cumulative network provided support for the observations made for the main component. Figures 20 to 23 supply support for the findings from the year 2001 which found that the more productive nodes tend to collaborate more and that they tend to collaborate across tracks. These results cement the fact that the results obtained from the main component of 2004 are quite exceptional. Like the year 2001, 2004 does not support the assumption of complete randomness. In displaying such strong track-based clustering it must be assumed that collaboration partners are chosen on the basis of their field of interest and knowledge within a field and not on a random basis. 67 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 In contrast to the findings of the main component for 2004, the second and third component revealed some geographical clustering. This result corroborates the findings of both the main component and the second and third component of 2001. The additional component analysis for 2004 provided dissimilar results with regards to track-based clustering. The main component displayed very strong track-based clustering while the second component showed some clustering, however, not nearly as strong as the main component. The third component contradict the main component as it exhibited no clustering. These findings indicate a tendency for the members of the second component to choose collaboration partners on the basis of both close geographical and cultural proximity and field of interest. In the third component close geographical proximity appears to be the main reason for collaboration partner selection. 6.4 EMAC Conference 2007 The most interesting finding from the year 2007 was that the main component exhibited some geographical clustering, especially around the University of Mannheim, Germany. Two other geographical clusters are comprised of researchers from the University of Maastricht, The Netherlands and Eindhoven University of Technology, The Netherlands, respectively. This result may be explained by a preference for working with people of close cultural and geographical proximity as described above in the section on the EMAC conference of 2001. Even though geographical clustering is present in the main component only four out of the twelve research papers in the component are co-authored by actors from the same institution. An additional interesting finding is the manner in which the researchers in the main component are separated according to track. Despite the fact that the main component is relatively large and the possibility of tracks overlapping therefore would be larger, it only showed minor track-based clustering. These results point towards a tendency for members of the main component to choose collaboration partners based mainly on close geographical/cultural proximity and to a minor degree according to field of interest. As in the main component of 2001, the most well connected node in the main component of 2007 has the highest score on all the centrality measures. Wetzels is in contact with or adjacent to many other actors in the network and can then be 68 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 characterised as the most important actor in the network as he occupies a strategically important position. In holding a central position in the network Wetzels is closer to other members of the network than any other actor. This means that he can access information rather quickly and that he will serve as a reference point for other nodes in the network. Like De Wulf´s links in 2001, the connections of Wetzels can clarify the structure of the EMAC community. The main component of 2007 supports the observation concerning author productivity and collaboration made for the year 2001. Figure 24 and 25 revealed that the most productive actors tend to collaborate more and to collaborate across tracks. Again all three central actors in the main component have worked on numerous tracks. This lends support to the suggestion that the EMAC community to some degree is comprised by specialists. However, as mentioned above, further research on this should be conducted before making a general assumption. In accordance with the findings of 2001 and 2004, the main component of 2007 does not corroborate the assumption of complete randomness. Collaboration partners seem to be selected on the basis of both close geographical/cultural proximity and according to field of interest, as mentioned above. Further investigation of the second and third largest components in the cumulative network provided support for the original results from the main component, i.e. they also displayed geographical clustering. Both the second and the third component exhibited some clustering lending support to the suggestion that actors in the EMAC community are inclined to work with researchers of close geographical and cultural proximity. The additional analysis of the second component revealed relatively strong track-based clustering contradicting the findings from the main component. This indicates that the nodes in this specific component choose collaboration partners based on both geographical proximity and field of interest. The third component supports the initial findings of the main component as it displays minor track-based clustering. As with the main component, the members of the third component are inclined to select collaboration partners mainly on the basis of close geographical and cultural proximity and to a lesser extent because of field of interest. 69 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 6.5 EMAC Conference 2010 The study at hand found the main component of 2010 to display strong geographical clustering around the universities of Hamburg, Cologne and Innsbruck, respectively. This result can, as mentioned above, be explained by a preference of the members of the main component to collaborate with authors of close geographical and cultural proximity. Another interesting finding is the way in which the nodes in the main component are divided according to track. The actors in the main component work in many different tracks but some degree of track-based clustering still emerges around two actors. These results point to members of the main component choosing collaboration partners on the basis of both close geographical and cultural proximity and field of interest. Like the years 2001 and 2007, the most well connected actor in the main component of 2010 has the highest score on all the centrality measures. This identifies Völckner as a significant actor in the main component for 2010 as she occupies a hub position in the network. As with the central actors in main components discussed above, Völckner is a popular collaboration partner and will therefore more likely hear of new research methods, terms and concepts before other actors who are not so well connected. She will then be a mediator for information in the network. The main component for 2010 confirms the observations made for the main components of 2001 and 2007 and for the additional components of 2004 suggesting a connection between author productivity and collaboration (see Figure 30 and 31). Again the three most active nodes have all collaborated on more than one track. This discovery corroborates the suggestion made above that the authors in these components tend change collaboration partners when they work within different fields in marketing. Again caution should be taken in making a general assumption before additional research on this result has been made. The results of the analysis of the main component of 2010 provided further support for the observations made regarding randomness in the other three years. The members of the main component of 2010 appear to select collaboration partners based on either close geographical and cultural proximity or field of interest and not at a random basis. 70 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Additional analysis of the second and third largest components in the cumulative network of 2010 revealed the same patterns with regard to geographical clustering as in the main component, i.e. strong clustering. However, the two additional components exhibited very strong track-based clustering. These results indicate a tendency for members of the second and third component in the year 2010 to choose collaboration partners according to field of interest rather than close geographical proximity. 7. Limitations A number of limitations exist for the study at hand. First of all, the current study considers only one aspect of research collaboration, namely co-authorship in a conference setting. By omitting books and journal articles outside the EMAC conference setting significant contributions to knowledge generation are not considered. Second, single authored research papers are not included in the study and this offers a drawback to the methodology adopted in the present study as researchers publishing alone also add to the generation of knowledge within a field. Third, a possibility that two authors co-authored a paper before 2000 exists, but in the present data set they appear as disconnected because the focus of this study is only on 2000-2010. This poses a methodological disadvantage to the study but is a consequence of the limited time frame studied. 8. Further Research The present study provides the basis for further studies of the way in which members of the EMAC community collaborate on scientific research papers. It would be relevant to perform a series of interviews with actors of the EMAC network in order to make more accurate assumptions about collaboration in the network. An interesting topic in the interviews would be the year 2004 as it would be relevant to establish the motivation behind the research paper that formed the basis of the main component of 2004. As this year proved to be quite exceptional it would be interesting to find out why so many authors collaborated on this specific research paper. The interviews should also be designed to give information on the degree to which researchers in this specific network tend to specialise. This will provide a deeper insight into the way in which actors choose collaboration partners. An additional yield from the interviews should be more information regarding the more productive researchers in the community. Why do they 71 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 collaborate more? And why do they appear to collaborate across more tracks than less productive actors? For future research purposes, it would also be interesting to explore how researchers initially join the EMAC community. Is it through association with frequently published authors? Such as when Ph.D. students publish with their dissertation advisor. Or is it because they are affiliated with institutions which are productive in EMAC context and thus participate with numerous research papers in every annual conference? In order to acquire more information on how knowledge is generated and shared among this group of researchers it could be relevant to extent the analysis to include citation analysis. This will add to the understanding of the structure of the network and provide a more complete picture of the network as a whole. The strength of the ties between the actors in the EMAC community, i.e. the number of research papers any two actors have produced together, has only been mentioned briefly in the study at hand. Additional research on the influence of tie strength on the collaboration structure of the network could be interesting. 9. Conclusion The present study has demonstrated the application of Social Network Analysis to coauthorship in a conference setting. The objective of the study was to analyse the structure of the collaboration network of the EMAC community and to unveil patterns and regularities in the choice of collaboration partners of the members of this specific community over time. The structure of the EMAC scientific research community is characterised by a number of highly visible authors who dominate the individual years. These researchers occupy central positions in the network from which knowledge (and possibly also research strategy) is pushed out. In holding key positions in the network these actors will automatically become leading channels of relational information and will naturally become popular collaboration partners. As the central nodes in the network are more 72 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 likely to hear of new research methods, terms, concepts and theories first they serve as reference points for other actors in the network. A very interesting finding to emerge from the study was that the central and more productive actors in the EMAC community tend to collaborate more and that they tend to collaborate in a more diverse set of tracks than other less active authors. This could, as mentioned earlier, be an interesting topic for further research. The purpose of the current study was also to determine which factors influence the choice of collaboration partners in the EMAC research community. The study at hand provided varying results for the three components in the four years under investigation. The primary factor of influence when choosing collaboration partners was found to be close geographical and cultural proximity as indicated in the majority of the components in the analysis. This points to a tendency for members of the EMAC community to be organised around institutions. In a number of the components in the study at hand the selection criteria was a combination of close geographical/cultural proximity and field of interest as both factors appeared to equally influence the choice of collaboration partners. In other components researchers relied mainly on the field of interest when selecting collaboration partners. This was especially true for the main component of 2004 which proved to be quite exceptional. As the results generated by this component were exraordinary no general conclusions about the network should be drawn from this specific component. In accordance with previous research the present study has shown a general increase in the number of authors who have participated in the EMAC conferences with coauthored research papers. As suggested this result could be an indication of increased specialisation in the network. This is further supported by the fact that central actors tend to change collaboration partners according to the topic of the research paper. Social network analysis of co-author networks gives an interesting insight into the sociology of scientific workers. The findings of the study at hand adds substantially to the understanding of the way in which scholars in the European Marketing Academy work together to produce knowledge. 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Ahmed, Sadrudin A. Ali, Abdul Manan Ali, Haider Ali, M. Yunus Alvarez, Begoña Alvarez, M. Teresa Alvarez Andersen, AnneMette Sonne Andersen, Otto Andersen, Poul Houman Anderson, Helén Anderson, Susan Andrews, Jonlee Andrews, Lynda Anthony, Christina Anthony, Janine Antonella, Carú Antonella, Cugini Armario, Enrique Martin Armario, Julia Martin Arnold, Armin Arnold, Mark J. Backhaus, Christof Backhaus, Klaus Baker, Ellen Baker, Michael Baker, Susan Baker, William Bal, Charles Bal, Rene Banerjee, Madhumita Banerjee, Subhabrata Bobby Barnes, Bradley Barnes, Stuart Adams Adamsle Ahmedper Ahmed Aliab Ali Aliyu Alvarez Alvarezte Andersenmet Andersen Andersenpou Andersonhel Anderson Andrewsjon Andrews Anthony Anthonyjan Antonella Antonellacu Armario Armarioju Arnoldar Arnold Backhauschri Backhaus Bakerell Bakermi Bakersu Baker Bal Balre Banerjee Banerjeesub Barnes Barnesstu 79 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Bauer, András Bauer, Hans H. Bauer, Martina Becker, Florian Becker, Jan Becker, Jochen Becker, Katja Becker, Kip Bell, David Bell, Pauline Bell, Simon Bengtsson, Anders Bengtsson, Maria Benito, Gabriel R. G. Benito, Leandro Bennett, Dag Bennett, Rebekah Bennett, Roger Black, Iain Black, Nancy J. Brady, John Patrick Brady, Mairead Brennan, Mike Brennan, Ross Broderick, Amanda J. Broderick, Anne Broderick, Leigh J. Brown, James R. Brown, Jennifer Brown, Joanne Brown, Steven P. Brown, UrsulaSigrid Byrne, Angela Byrne, Gabriel J. Carneiro, Jorge Carneiro, Maria João Castro, Alberto Joao C. De Castro, Andres Mazaira Castro, Luciano Thomé Castro, Luís m. de Chan, Jit Chan, Priscilla Y. I. Chan, Ricky Y. K. Bauerand Bauer Bauermar Becker Beckerjan Beckerjoc Beckerkat Beckerkip Bellda Bellpau Bell Bengtsson Bengtssonmar Benitogab Benito Bennettdag Bennettre Bennett Blackia Black Brady Bradymai Brennan Brennanro Broderick Broderickan Brodericklei Brown Brownjen Brownjoa Brownste Brownur Byrne Byrnegab Carneiro Carneiromar Castroal Castro Castroluci Castrolu Chanjit Chan Chanri 80 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Chan, Tze Wee Chandon, Jean-Louis Chandon, Pierre Chen, Bo-Wei Chen, Chen-Yueh Chen, Chien-Hung Tom Chen Chen, Fu-Tang Chen, Kuang-Wei Chen, Shu-Ching Chen, Yuxin Chen, Zhimin Chien, Charles Chien, Pi-Hsuan Monica Chou, Ting-Jui Chou, Ting-Ting Christensen, Alice Slater Christensen, Anne Marie Christensen, Bjørn Christensen, Lars Bech Christensen, Sverre Riiss Claro, Danny Pimentel Claro, Priscila B. Oliveira Clark, Lindie Clark, Moira Clarke, Gary Clarke, Ian Coelho, Arnaldo Coelho, Filipe Cornelissen, Joep P. Cornelissen, Markus Costa, Claudia Costa, Filipe Campelo Xavier Da Costa, Jorge Cowley, Elizabeth Cowley, Kym Cox, David Cox, Tony Dahan, Ely Dahan, Mariana Medvetchi Chantze Chandonjea Chandon Chenbo Chen Chenchi Chenfu Chenkuan Chenshu Chenyu Chenzhi Chien Chienpi Chou Chouti Christensenal Christensen Christensenbjø Christensenlar Christensensver Claro Claropri Clark Clarkmo Clarke Clarkeian Coelhoarn Coelho Cornelissen Cornelissenmar Costaclau Costafi Costa Cowley Cowleykym Coxda Cox Dahan Dahanmari 81 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Da Silva, Danielle Mantovani Lucena Da Silva, Helenita R. Da Silva, Jorge Ferreira Daskou, Antonia Daskou, Sofia Davies, Andrea Davies, Iain A. Dawes, John Dawes, Philip L. Denis, Jean-Emile Denis, Sylvain Derbaix, Christian Derbaix, Maud Devlin, Elinor Devlin, James F. De Wet, Dries De Wet, Thinus Dias, Campos Roberta Dias, José G. Diehl, Kristin Diehl, Sandra Dimitriadis, Nikos Dimitriadis, Sergios Elliott, Richard Elliott, Statia Esteban, Águeda Esteban, Mercedes Evans, Jody Evans, Martin Falkenberg, Andreas Falkenberg, Loren Farrell, Colin Farrel, Mark Fernandes, Daniel Fernandes, Joana Cosme Fernandez, Angel Nogales Fernández, Estela Fernández, Pilar Ferrín Fernandez, Guillen Fernandez, Margarita Ferreira, Alcina Da Silvadan Da Silva Da Silvajor Daskouan Daskou Davies Daviesia Dawesjo Dawes Denisjea Denis Derbaix Derbaixma Devlinel Devlin De Wet De Wetthi Dias Diasjo Diehlkri Diehl Dimitriadis Dimitriadisser Elliott Elliottsta Estebanágu Esteban Evans Evansmar Falkenberg Falkenberglo Farrellco Farrell Fernandes Fernandesjo Fernandezan Fernándezest Fernández Fernandezgui Fernandez Ferreiraalc 82 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Teresa Gaspar Ferreira, Armando Leite Ferreira, Jorge Ferreira, Marco Fischer, Bettina Fischer, Marc Fischer, Wolfgang Fletcher, Keith Fletcher, Richard Fournier, Christophe Fournier, Susan Frank, Halsig Frank, Lauri Fry, Marie-Louise Fry, Tim Fu, Guoqun Fu, Isabel Fuchs, Christoph Fuchs, Dion Fuchs, Sebastian Gabrielsen, Gorm Gabrielsen, Tommy Ganesan, Rama Ganesan, Shankar Gao, Hongzhi Gao, Yuhui Garcia, Christina García, Iñaki García, Irene Garcia, José Luis Garcia, Rosanna García, Rosario García, Teresa Garnier, Aime Isabelle Garnier, Marion Garrett, Jason Garrett, Tony Geiger, Ingmar Geiger, Susi Gomez, Jaime Gomez, Jorge Gomez, Miguel Angel Gomez, Monica Suarez Gomez, Pierrick González, Celina Ferreiraarm Ferreira Ferreiramar Fischerbe Fischer Fischerwol Fletcher Fletcherri Fournier Fourniersu Frank Franklau Frymar Fry Fu Fuis Fuchschri Fuchs Fuchsseb Gabrielsengo Gabrielsen Ganesanra Ganesan Gaohong Gao Garcia Garcíaiñ Garcíair Garciajos Garciaro Garcíarosa Garcíater Garnier Garniermar Garrettja Garrett Geigering Geiger Gomezjai Gomezjor Gomezmi Gomezmon Gomez Gonzálezcel 83 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Gonzalez, José González, Elisa Alén Gonzalez, Maria Victoria Roman González, Óscar González, Santiago González, Varela Gopalakrishna, Pillai Kishore Gopalakrishna, Srinath Graham, John Graham, Stuart Grant, David Grant, Ian Griffin, Abbie Griffin, Deborah Gruber, Barbara Gruber, Thorsten Haase, Kerstin Haase, Nora Hansen, Flemming Hansen, Jonas Eder Hansen, Kåre Hansen, Lotte Yssing Hansen, Søren Sten Hansen, Torben Hansen, Felix Harris, Fiona Harris, Jennifer Harris, Kim Harris, Lloyd C. Harris, Patricia Harris, Phil Hartmann, Adriane Hartmann, Benjamin Julien Hartmann, Evi Hartmann, Patrick Heide, Morten Heide, Jan Helm, Roland Helm, Sabrina Hernández, Carlos Hernández, Rosa Herrmann, Andreas Herrmann, Jean-Luc Horváth, Csilla Gonzalezjo Gonzálezeli Gonzalezmar Gonzálezos González Gonzálezvar Gopalakrishnapil Gopalakrishna Graham Grahamstu Grant Grantian Griffinab Griffin Gruberbar Gruber Haase Haaseno Hansenfle Hansenjo Hansen Hansenlot Hansensør Hansentor Hansenfel Harrisfi Harrisjen Harriskim Harrislloy Harris Harrisphi Hartmann Hartmannben Hartmannevi Hartmannpat Heidemo Heide Helmro Helm Hernández Hernándezro Herrmannan Herrmann Horváth 84 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Horváth, Dóra Hoffmann, Arvid Hoffmann, Jonas Hoffmann, Stefan Hogg, Gill Hogg, Margaret K. Hoppe, Daniel Hoppe, Melanie Huber, Frank Huber, JanAlexander Hubert, Marco Hubert, Mirja Hughes, Mathew Hughes, Paul Hunter, Erik Hunter, Louise E. Iyer, Easwar S. Iyer, Gopalkrishnan Jaakkola, Elina Jaakkola, Matti Jiang, Minghua Jiang, Zixi Jimenez, Ana Isabel Zarco Jiménez, David Jiménez, Julio Jiménez, Nadia Johanson, Jan Johanson, Martin Johansson, Johny Johansson, Ulf Johnson, Camille Johnson, Eric J. Johnson, Jean L. Johnson, Michael D. Jones, Jones Jones, Marilyn Y. Jones, Richard Jones, Rosalind Jones, Sandra C. Jung, Kathrin Jung, Susan Kahn, Kenneth B. Kahn, Mubbsher Munawar Kaiser, Christian Kaiser, Jonas Kaiser, Ulrike Horváthdo Hoffmannar Hoffmannjon Hoffmann Hogggi Hogg Hoppedan Hoppe Huber Huberjan Hubert Hubertmi Hughes Hughespa Hunter Hunterlou Iyereas Iyer Jaakkolael Jaakkola Jiangmi Jiang Jimenezana Jiménezda Jiménezju Jiménez Johanson Johansonmar Johansson Johanssonulf Johnsonca Johnsoner Johnson Johnsonmi Jones Jonesmar Jonesri Jonesro Jonessan Jungkath Jung Kahnken Kahn Kaiser Kaiserjon Kaiserul 85 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Kang, Seung-Mo Kang, Suk-Hou Kaya, Berhan Kaya, Maria Kefi, Samy Kefi, Zied Keller, Thomas Keller, Veronika Kemp, Gill Kemp, Ron Kent, Anthony Kent, Raymond A. Kim, Dong Ryul Kim, Eun Young Kim, Hye-ran Kim, Hyoung Gil Kim, Jaehwan Kim, Jonathan Kim, Jong Ho Kim, Jungkeun Kim, Jung Kyun Kim, Ju-Young Kim, Keysuk Kim, Kwang-Seok Kim, Kyung Hoon Kim, Myung Soo Kim, Namwoon Kim, Pan Joon Kim, Stephen Kim, Yevgeniay Kim, Young-man Klaus, Martin Klaus, Phil Klein, Alex Klein, Kristina Klein, Maren Knight, Dee K. Knight, John Koch, Christof Koch, Jochen Kozak, Metin Kozak, Robert A. Kumar, Alok Kumar, Nirmalya Kumar, Rajesh Kwon, Jun Hyuk Kwon, Ohjin Lages, Carmen Kangseu Kang Kayaber Kaya Kefisa Kefi Kellertho Keller Kempgi Kemp Kentan Kent Kimry Kimeun Kimhye Kimgil Kimjae Kimjo Kimho Kimjung Kimkyun Kim Kimkey Kimkwa Kimhoon Kimsoo Kimnam Kimpan Kimsteph Kimyev Kimyou Klausmar Klaus Klein Kleinkri Kleinma Knightdee Knight Kochchri Koch Kozak Kozakro Kumar Kumarnir Kumarra Kwon Kwonoh Lages 86 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Lages, Cristina Raquel Lages, Luis Lages, Natalia Laroche, Mariane Laroche, Michel Laroche, Patrice Larsen, Gretchen Larsen, Ketil Faldmark Larsen, Nils Magne Laurent, Florés Laurent, George Laurent, Gilles Lee, Angela Y. Lee, Bernard Lee, Chang Han Lee, Christina Lee, Don Lee, Dong-Hae Lee, Hsin-Hsuan Lee, Hye Jung Lee, Hyun Seung Lee, Janghyuk Lee, Jimmy Lee, Jong-Ho Lee, Jong-Hwan Lee, Jooyun Lee, Ka Lee, Michael S. W. Lee, Nicholas Lee, Nick Lee, Seung-Hee Lee, Seung-Hwan Lee, Wonkyong Lee, Zoe S. Leonidou, Constantinos Leonidou, Leonidas Lewis, Barbara R. Lewis, Christopher Lewis, Tony Lim, Elison Lim, Lynn L. K. Liu, Ben ShawChing Liu, Hong Liu, Jia Liu, Martin Jen- Lagesra Lageslu Lagesna Larochemar Larochemi Laroche Larsengre Larsenke Larsen Laurentflo Laurentgeo Laurent Leeang Leeber Leecha Leechri Leedon Leedong Leehsin Leehye Leehy Leeja Lee Leejoho Leejohw Leejoo Leeka Leemic Leenich Leeni Leehee Leeseu Leewon Leezo Leonidoucon Leonidou Lewisba Lewis Lewiston Limel Lim Liuben Liuho Liujia Liumar 87 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Yuan Liu, Pei Fen Liu, Raymond Liu, Rebecca Liu, Tingchi Lopez, Carmen Lopez, Jose Angel Sanchez López, Inés López, Moreno Lorenza Lopéz, Nicolas Carolina López, Pilar Lopez, Raquel Antolín Lu, Irene R. R. Lu, Junxiang Lu, Vinh Luna, David Luna, Paula Lutz, Antje Lutz, Salla Ma, Katherine H. Y. Ma, Shan-Lyn Ma, Yu Ma, Zhenfeng Marques, Alzira Marques, Catarina Marques, Susana Martin, Brett Martin, Christopher Martin, Dan Martin, Oscar Martin, Pedro Juan Martin, Xavier Martínez, Carlos Antonio Martinez, Carole Martínez, Eva Martínez, Francisco José Mattsson, Jan Mattsson, LarsGunnar McDonald, Heath McDonald, Seonaidh Meier, Doreen Meier, Helena Liupei Liuray Liureb Liu Lopezcar Lopez Lópezin López Lopéznic Lópezpil Lopezra Luir Lu Luvi Luna Lunapau Lutzan Lutz Makath Mashan Ma Mazhen Marquesal Marquescat Marques Martin Martinchri Martindan Martinosc Martinped Martinxav Martínez Martinezcaro Martínezeva Martínezfran Mattsson Mattssonlar McDonald McDonaldseo Meierdo Meier 88 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Melnyk, Valentina Melnyk, Vladimir Menezes, João Menezes, Rui Michaelis, Lea Michaelis, Manuel Michel, Géraldine Michel, Stefan Miller, Ken Miller, Klaus Miller, Rohan Mizerski, Dick Mizerski, Kate Moeller, Lise Moeller, Timo Moeller, Sabine Molina, Arturo Molina, Castillo Francisco José Morgan, Neil Morgan, Robert Morton, Fiona Scott Morton, Peta Mousley, Ben Mousley, Wendy Möller, Jana Möller, Kristian Mueller, Barbara Mueller, Rene D. Mueller, Steffen Müller, Brigitte Müller, Melanie Nagy, Gabor Nagy, Szabolcs Nancarrow, Clive Nancarrow, Pamela Navarro, Angeles Navarro, Antonio Nelson, Charlie J. Nelson, James Nelson, Leif Nelson, Michelle R. Neumann, Debra Neumann, Marcus M. Nguyen, Cathy Nguyen, Tho Nguyen, Trang Melnyk Melnykvla Menezes Menezesrui Michaelis Michaelisman Michel Michelste Millerken Miller Millerro Mizerskidi Mizerski Moellerlis Moellerti Moeller Molinaart Molina Morganne Morgan Mortonfi Morton Mousleyben Mousley Möllerja Möller Muellerbar Muellerre Mueller Müller Müllermel Nagy Nagysza Nancarrow Nancarrowpam Navarroang Navarro Nelson Nelsonja Nelsonle Nelsonmich Neumann Neumannmar Nguyencat Nguyen Nguyentra 89 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Nielsen, Brian Nielsen, Anne Ellerup Olsen, G. Douglas Olsen, Lars Erling Palmer, Adrian Palmer, Roger Patterson, Maurice Patterson, Paul Paul, Gordon W. Paul, Michael Pauwels, Koen Pauwels, Pieter Peattie, Ken Peattie, Sue Pereira, Hélia Goncalves Pereira, Rosaria Pereira, Teresa Peters, Kim A. Peters, Philipp Polo, Peña Ana Isabel Polo, Yolanda Poulis, Efthimios Poulis, Konstantinos Proenca, João F. Proenca, Reinaldo Rajh, Edo Rajh, Suncana Piri Ramanathan, Anand Ramanathan, Ram Rao, Sally Rao, Vithala R. Reed, Americus Reed, Gary Reid, Mike Reid, Susan Reinhold, Michael Reinhold, Stephan Reynolds, Kate Reynolds, Kristy E. Reynolds, Nina L. Rivas, Eduardo Rivas, Javier Alonso Rivera, Jaime Rivera, Pilar Robben, John Robben, Roderick Nielsen Nielsenan Olsen Olsenlar Palmer Palmerro Pattersonmau Patterson Paulgor Paul Pauwels Pauwelspie Peattie Peattiesue Pereirahél Pereiraro Pereira Peterski Peters Polo Poloyo Poulis Pouliskon Proenca Proencarei Rajh Rajhsun Ramanathan Ramanathanram Raosa Rao Reedam Reed Reidmi Reid Reinhold Reinholdste Reynolds Reynoldskri Reynoldsni Rivas Rivasjav Riverajai Rivera Robben Robbenrod 90 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Robson, Andrew Robson, Matthew Rodrigues, Luiza Rodrigues, Paula Rodríguez, Ana Isabel Rodríguez, Manuel Rodríguez, Molina Miguel Angel Rodríguez, Pinto Javier Rodríguez, Rosa María Romero, Carlota Lorenzo Romero, Jaime Rose, Gregory M. Rose, John Rossi, Carlos Alberto Vargas Rossi, Peter Roth, Katharina Petra Roth, Stefan Rowe, Amanda T. Rowe, Susan Rubio, Ana Garrido Rubio, Luis Rubio, Natalia Ruiz, Carla Ruiz, David Martin Ruiz, Enar Ruiz, Molina Maria Eugenia Ruiz, Rocio Rangel Ruiz, Salvador Russell, Cristel Russell, Dale Sackett, Anna Sackett, Aron Saker, Jim Saker, Merav Salavou, Eleni Salavou, Helen Salazar, Ana Salazar, Maria T. Sánchez, Isabel Sánchez, Javier Sánchez, Manuel Robson Robsonmat Rodrigues Rodriguespau Rodríguezana Rodríguezma Rodríguez Rodríguezpin Rodríguezrosa Romerocar Romero Rose Rosejo Rossicar Rossi Rothkat Roth Rowe Rowesu Rubioana Rubiolu Rubio Ruiz Ruizda Ruizen Ruizmol Ruizro Ruizsa Russell Russellda Sackettan Sackett Saker Sakerme Salavou Salavouhel Salazar Salazarmar Sánchezisa Sánchezja Sánchezma 91 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Sánchez, Raquel Sánchez, Teresa Santos, Cristiane Santos, Jessica Santos, José Santos, Libia Santos, Maria Da Conceicão Santos, Mirela Santos, Rubens Da Costa Santos, Vijande Maria Leticia Schmidt, Marcus Schmidt, Svenja Schmidt, Thomas Schmidt, Thorsten Schmidt, Volker Schmitt, Julien Schmitt, Philipp Schmitt, Robert Schulze, Caroline Schulze, Timo Scott, Adrianne Scott, Jane Sharma, Neha Sharma, Neeru Sharp, Anne Sharp, Byron Shaw, Deirdre Shaw, Mike Shaw, Robin N. Shaw, Vivienne Shin, Jong-Kuk Shin, Meongijn Silva, Carla Silva, Catarina Silva, Maria Jose Simon, Henrik Simon, Judith Simon, Steven J. Sinclair, Julie Sinclair, Thea Singh, Jagdip Singh, Jaywant Singh, Ramendra Singh, Satyendra Singh, Siddharth Sinha, Ashish Sánchez Sánchezter Santoscri Santosjes Santosjo Santosli Santosmar Santosmi Santosru Santos Schmidtmar Schmidt Schmidttho Schmidtthor Schmidtvol Schmitt Schmittphi Schmittro Schulzecar Schulze Scottad Scott Sharma Sharmanee Sharp Sharpby Shawde Shawmi Shawro Shaw Shinjo Shin Silva Silvacat Silvamar Simon Simonju Simonste Sinclair Sinclairthe Singhjag Singhjay Singh Singhsaty Singhsid Sinhaas 92 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Sinha, Prabhakant Slater, Rod Slater, Stanley F. Slater, Stephanie Smit, Edith Smit, Willem Smith, Andrew Smith, A. P. Smith, Daniel C. Smith, Gareth Soares, Ana Soares, Elsa Sood, Ashish Sood, Sanjay Song, In Am Song, Michael Song, Sangyoung Srivastava, Rajendra Srivastava, Rajesh Steiner, Michael Steiner, Susanne Steiner, Winfried J. Sun, Daewon Sun, Luping Taylor, Charles R. Taylor, Gail Taylor, Paul Teichmann, Karin Teichmann, MaikHenrik Thompson, Jennifer Thompson, Yvonne Tuominen, Matti Tuominen, Sasu Van Der Lans, Ivo A. Van Der Lans, Ralf Van Dijk, Albert Van Dijk, Gert Villanueva, Julian Villanueva, María Luisa Vogel, Johannes Vogel, Verena Voss, Glenn Voss, Roediger Voss, Zannie Wagner, Janet Wagner, Ralf Sinha Slaterrod Slatersta Slater Smited Smit Smithan Smithap Smith Smithga Soares Soaresel Soodas Sood Songin Song Songsang Srivastavarajen Srivastava Steinermi Steinersus Steiner Sun Sunlu Taylorchar Taylor Taylorpa Teichmannka Teichmann Thompson Thompsonyv Tuominen Tuominensa Van Der Lans Van Der Lansra Van Dijkal Van Dijl Villanueva Villanuevamar Vogeljo Vogel Vossgle Voss Vosszan Wagnerjan Wagner 93 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Wagner, Stephan M. Wagner, Udo Walker, Joan L. Walker, Rhett Walter, Achim Walter, Eva Wang, I Chen Wang, Lai-Wang Wang, Qing Wang, Weiyue Wang, Yantao Ward, Janet Ward, Ronald W. Weber, Bernd Weber, Karin Wilke, Annika Wilke, Ricky Wilke, Sina Wilson, Alan Wilson, Brad Wilson, Elaine Wilson, Juliette Wong, Ipkin Wong, Mandy Wong, Nancy Wong, Veronica Wright, George Wright, Len Tiu Wright, Malcom Wright, Owen Wu, Steven Wu, Wann-Yih Xie, Chunyan Xie,Ying Yang, Rae Jin Yang, Yinghui Young, J. A. Young, Karen Young, Louise Young, Scott H. Yu, Tiffany HuiKuang Yu, Ting Yu, Wantao Zhang, Hongbo Zhang, Jing Zhang, John Zhang, Lida Wagnerste Wagnerudo Walkerjo Walker Walterach Walter Wangi Wanglai Wang Wangwe Wangyan Wardja Ward Weberbe Weber Wilkean Wilke Wilkesi Wilsonal Wilsonbrad Wilson Wilsonju Wong Wongma Wongnan Wongve Wrightgeo Wrightlen Wright Wrightow Wuste Wu Xiechu Xie Yang Yangra Youngja Youngka Younglou Young Yutif Yu Yuwan Zhanghong Zhangji Zhang Zhangli 94 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Zhang, Ting Zhu, Judy Li Zhu, Tian Zhangti Zhu Zhuti 95 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Appendix 2: Track List Tracks as listed in the EMAC conference proceedings. Track 1: Advertising, Promotion and Marketing Communication Track 2: Business-to-Business Marketing and Networks Track 3: Consumer Behaviour Track 4: Innovation and New Product Development Track 5: International and Cross-Cultural Marketing Track 6: Marketing in Emerging and Transition Economies Track 7: Marketing of Public and Non-Profit Organisations Track 8: Marketing Research and Research Methodology Track 9: Marketing Strategy and Leadership Track 10: Marketing Theory 96 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Track 11: Modeling and Forecasting Track 12: New Technologies and E-Marketing Track 13: Pricing and Financial Issues in Marketing Track 14: Product and Brand Management Track 15: Relationship Marketing Track 16: Retailing, Channel Management and Logistics Track 17: Sales Management and Personal Selling Track 18: Service Marketing Track 19: Social Responsibility, Ethics and Consumer Protection Track 20: Tourism Marketing 97 A Social Network Analysis of the EMAC Annual Conferences 2000-2010 Appendix 3: Data CD 98