Gilberto Câmara, Earth System Science Center, INPE Collective Spatial Action Models: a Foundation for Assessing HumanEnvironment Interactions Workshop on Cognitive and Linguistic Aspects of Geographic Space, Las Navas, Spain, July 2010 1st Latin-American Computational Interdisciplinary Sciences Conference, São José dos Campos, August 2010 Licence: Creative Commons ̶̶̶̶ By Attribution ̶̶̶̶ Non Commercial ̶̶̶̶ Share Alike http://creativecommons.org/licenses/by-nc-sa/2.5/ Acknowledgments for using previous material Martin Nowak (Harvard University, USA) Francisco C. Santos (Université Libre de Bruxelles, Belgium) Craig Callender (Philosophy, Univ California San Diego, USA) Ana Aguiar (INPE, Brazil) Tiago Carneiro (Federal University of Ouro Preto, Brazil) Guy Brasseur (NCAR, USA) What cooperation can achieve... Those were the days… http://www.youtube.com/watch?v=0HrjevD2vhk&feature=related Collective spatial action: volunteered GI Are Brazilians less cooperative? Less tech-savvy? Does google solve their problems? Are they happy with their public data? Collective spatial action: pedestrian modelling Notting Hill Carnival (London) Batty, “Agent-Based Pedestrian Modelling”, in: Advanced Spatial Analysis, ESRI Press, 2003. Collective spatial action: deforestation CO2 emissions (PgC y-1) Collective spatial action: global change 10 8.7 8 Fossil fuel 6 9.9 PgC 4 Land use change 2 1960 1970 1980 1990 1.2 2000 2010 12% of total Le Quéré et al. 2009, Nature-geoscience, 2009 The fundamental question of our time How is the Earth’s environment changing, and what are the consequences for human civilization? We need cooperation at a global level… By the year 2050... 9 billion people: 6 billion tons of GHG and 60 million tons of urban pollutants. Resource-hungry: We will withdraw 30% of available fresh water. Risky living: 80% urban areas, 25% near earthquake faults, 2% in coast lines less than 1 m above sea level. An explicit spatial problem in global change: land change “Land-change science has emerged as a foundational element of global environment change and sustainability science” (Rindfuss et al, “Developing a science of land change”, PNAS, 2004). source: Global Land Project Science Plan (IGBP) Impacts of global land change More vulnerable communities are those most at risk We need spatially explicit models to understand human-environment interactions Nature: Physical equations Describe processes Society: Decisions on how to Use Earth´s resources 1973 1987 2000 Slides from LANDSAT images: USGS Modelling Human-Environment Interactions How do we decide on the use of natural resources? What are the conditions favoring success in resource mgnt? Can we anticipate changes resulting from human decisions? What GIScience techniques and tools are needed to model human-environment decision making? Clouds: statistical distributions Clocks, clouds or ants? Clocks: deterministic methods Ants: emerging behaviour Modelling collective spatial actions: the complex systems approach photo: Chico Albuquerque 1. 2. 3. 4. Situated individuals (persons, groups, agents) Interaction rules - communication Decision rules - actions Properties of space Conections and flows are universal Yeast proteins (Barabasi and Boneabau, SciAm, 2003) Scientists in Silicon Valley (Fleming and Marx, Calif Mngt Rew, 2006) Information flows generate cooperation National Cancer Institute, EUA http://visualsonline.cancer.gov White cells attact a cancer cell (cooperative activity) Complex adaptive systems Systems composed of many interacting parts that evolve and adapt over time. Organized behavior emerges from the simultaneous interactions of parts without any global plan. Is computing also a natural science? http://www.red3d.com/cwr/boids/ “Information processes and computation continue to be found abundantly in the deep structures of many fields. Computing is not—in fact, never was—a science only of the artificial.” (Peter Denning, CACM, 2007). Computing is also a natural science Computing studies information flows in natural systems... ...and how to represent and work with information flows in artificial systems Agent-Based Modelling: Computing approaches to complex systems Representations Goal Communication Communication Action Perception Environment Gilbert, 2003 Four types of spatial agents Artificial agents, artificial environment Artificial agents, natural environment Natural agents, artificial environment Natural Agents, natural environment source: Couclelis (2001) Some caution necessary... “Agent-based modeling meets an intuitive desire to explicitly represent human decision making. (…) However, by doing so, the well-known problems of modeling a highly complex, dynamic spatial environment are compounded by the problems of modeling highly complex, dynamic decision-making. (…) The question is whether the benefits of that approach to spatial modeling exceed the considerable costs of the added dimensions of complexity introduced into the modeling effort. The answer is far from clear and in, my mind, it is in the negative. But then I am open to being persuaded otherwise ”. (from “Why I no longer work with agents”, 2001 LUCC ABM Workshop) Helen Couclelis Some caution necessary... “Complexity is more and more acknowledged to be a key characteristic of the world we live in and of the systems that cohabit our world. It is not new for science to attempt to understand complex systems: astronomers have been at it for millennia, and biologists, economists, psychologists, and others joined them some generations ago. (…) If, as appears to be the case, complexity (like systems science) is too general a subject to have much content, then particular classes of complex systems possessing strong properties that provide a fulcrum for theorizing and generalizing can serve as the foci of attention.” (from “The Sciences of the Artificial”, 1996) Herbert Simon (1958) Our spatially explicit models need good social theories to guide them Nature: Physical equations Describe processes Society: Decisions on how to Use Earth´s resources We need social theories to understand humanenvironment interactions Survey Moran, “Environmental Social Science: Human-Environment Interactions and Sustainability” (2010) Social simulation Schelling, “Micromotives and macrobehavior” (1978). Batty, “Cities and complexity” (2005). Game theory von Neumann and Morgenstern, “Theory of games and economic behavior” (1944) Nash, "Equilibrium points in n-person games“ (1950). Evolutionary dynamics Maynard Smith, ”Evolution and the theory of games” (1982) Axelrod, “Evolution of cooperation” (1988). Novak, “Evolutionary dynamics: exploring the equations of life” (2005). Institutional analysis Ostrom, “Governing the commons” (1990). Social Simulation: Segregation Segregation is an outcome of individual choices But high levels of segregation indicate mean that people are prejudiced? Schelling’s Model of Segregation If people require more than 1/3 of neighbours to be of the same kind... ...ghettos are formed! Game Theory GT is an analytical tool for social sciences that is used to model strategic interactions or conflict situations. Strategic interaction: When actions of a player influence payoffs to other players Game Theory Explanation: What is the game to be played? Prediction: What outcome will prevail? Advice or prescription: Which strategies are likely to yield good results in which situations? Where can we use Game Theory? Any situation that requires us to anticipate our rival’s response to our action is a potential context for GT. Economics, Political science, Biology What is a Normal Form Game? Players: list of players Strategies: all actions available to all players Payoffs: a payoff assigned to every contingency (every possible strategy profile as the outcome of the game) John Kennedy and Nikita Khrushchev Modeling two-party games Payoffs for each player depend on actions of both Two possible strategies: A party cooperates when he performs value-increasing promises, and defects when he breaches Modeling choice in non-cooperative games Player 2 Cooperate Cooperate Player 1 Defect Defect Player 1 Both cooperate cooperates, Player 2 defects Player 1 defects, Player 2 cooperates Both defect The “chicken game” “Rebel without a cause” Two persons drive their cars towards a cliff. They must stop or both may die in the fall. The one that stops first will be called a "chicken," meaning a coward. The hawk-dove game (== chicken game) Two individuals compete for a resource (In biological terms, its value increases in the Darwinian fitness of the individual who obtains the resource) Hawk Initiate aggressive behaviour, not stopping until injured or until one's opponent backs down. Dove Retreat immediately if one's opponent initiates aggressive behaviour. Maynard Smith and Price, "The logic of animal conflict“ (Nature, 1973 ) The hawk-dove game (== chicken game) Encyclopedia Britannica The stag-hunt game: conflict between safety and social cooperation Two hunters want to kill a stag. Success is uncertain and, if it comes, require the efforts of both. On the other hand, either hunter can forsake his partner and catch a hare with a good chance of success. The stag-hunt game: conflict between safety and social cooperation C D C 10,10 0,6 D 6,0 5,5 Rousseau, in A Discourse on Inequality: “If it was a matter of hunting a deer, everyone well realized that he must remain faithful to his post; but if a hare happened to pass within reach of one of them, we cannot doubt that he would have gone off in pursuit of it without scruple..." Prisoners’ Dilemma Two suspects are caught and put in different rooms (no communication). They are offered the following deal: 1. If both of you confess, you will both get 3 years in prison 2. If you confesses whereas the other does not, you will get 1 year and the other gets 5 years in prison . 3. If neither of you confess, you both will get 2 years in prison. Generalizing... Cooperation requires at least two individuals: A: the one providing cooperation (DONOR) B: the one benefiting from cooperation (RECEIVER) Donor has a cost c to cooperate and confers a benefit b to other player C D C b–c -c D b 0 you Payoff matrix other Terminology Player 2 T = Temptation to defect R = Reward for mutual cooperation P = Punishment for mutual defection S = Sucker's payoff Generalizing... Payoff matrix R: mutual cooperation other P: mutual defection C D C R(1) S(-c) D T(b) P(0) S : sucker’s payoff T : temptation to defect you Taking R = 1 and P = 0 Generalizing... Payoff matrix R: mutual cooperation opponent P: mutual defection C D C 1 S D T 0 S : sucker’s payoff T : temptation to defect you Taking R = 1 and P = 0 Different ordering -> Different tensions greed C D C R S D T P fear Chicken game T >1 > S > 0 Stag-hunt game 1>T > 0 > S Prisoner’s dilemma T >1 > 0 > S (Macy&Flache, PNAS 2002) Tragedy of the Commons (Hardin, 1968) Assume a common-property resource (exclusion is difficult and joint use involves subtractability) with no property rights. (Pasture open to all) Each herdsman tries to keep as many sheep as possible on the commons. Each tries to maximize gain. Add those sheep! The rational herdsman concludes that he should add another sheep. And another…And another…And so does each herdsman “Ruin is the destination toward which all men rush, each pursuing his own best interest…” Prisioner´s Dillema as a Model for the Tragedy of the Commons 1. Suppose the commons can support 2 sheep at no cost and that each additional sheep put in the commons has a cost of 1/3 of its price due to overgrazing. 2. Assume two herdsman with one sheep on the commons each. 3. If a herdsman puts another sheep in the commons, he receives all the proceeds from the sale of each additional animal. His temptation is 4/3 and the sucker´s payoff for the other herdsman is -1/3. Prisioner´s Dillema as a Model for the Tragedy of the Commons You are the herdsman. What are your options? Do you cooperate or defect? C D C 1 -1/3 D 4/3 1/3 you Payoff matrix other Tragedy of the Commons? Everybody’s property is nobody’s property (Hardin) Preconditions for the tragedy of the commons Lack of restraint on pursuits of self-interest Consequences are externalities (I don’t have to pay) Externalities in the global commons Activity of one person has an impact on the well-being of another. Positive externalities (or external benefits): Benefits realized by those who didn’t pay for them. Negative externalities (or external costs): Costs borne by those who didn’t generate them. Byproducts that harm others. SUVs in USA Climate Change in Africa Is the tragedy of the commons inevitable? Experiments show that cooperation emerges if virtuous interactions exist source: Novak, May and Sigmund (Scientific American, 1995) Repeated prisioner´s dillema Four different strategies for repeated prisioner´s dillema source: Novak, May and Sigmund (Scientific American, 1995) Repeated prisioner´s dillema Evolution of prisioner´s dillema comparing different strategies source: Novak, May and Sigmund (Scientific American, How can cooperation happen? Nowak MA (2006). “Five rules for the evolution of cooperation” Science 314:1560-1563 (most highly cited multidisciplinary paper – ISI, 1st quarter 2010) "I would lay down my life for two brothers or eight cousins“ (J.B.S. Haldane) Five rules for evolution of cooperation b = benefit for the recepient c= cost for the donor Common pool resources (Elinor Ostrom) The ultimate common pool resource Governing the commons [Ostrom, Science, 2005] Governing the commons: Ostrom´s conditions 1. Clearly defined boundaries 2. Congruence between appropriation and provision rules and local conditions 3. Collective-choice arrangements: 4. Monitoring and graduated Sanctions. 5. Conflict-resolution mechanisms 6. Minimal recognition of rights to organize. 7. Organized governance activities. Ostrom on governing the commons “The challenge is how best to limit the use of natural resources so as to ensure their long-term economic viability.” “Neither the state nor the market is uniformly successful in enabling individuals to sustain long-term, productive use of natural resource systems.” “Optimal equilibrium with centralized control is based on assumptions concerning accuracy of information, monitoring capabilities, sanctioning reliability, and zero costs of administration.” Modelling collective spatial actions: potential GIScience contributions Agent Agent Space Space Benenson and Torrens, “Geographic Automata Systems”, IJGIS, 2005 (but many questions remain...) Scientists and Engineers Photo 51(Franklin, 1952) Scientists build in order to study Engineers study in order to build Spatially-explicit land change models Explain past changes, through the identification of determining factors of land use change; Envision which changes will happen, and their intensity, location and time; Assess how choices in public policy can influence change, by building different scenarios considering different policy options. TerraME: Computational environment for developing nature-society models Cell Spaces Support for cellular automata and agents Tiago Carneiro, “Nested-CA: A Foundation for Multiscale Modelling of Land Use and Land Cover Change”, INPE, 2006. TerraME´s components [Carneiro, 2006] 1. Get first pair 2. Execute the ACTION 3. Timer =EVENT 1. 1:32:00 Mens. 1 2. 1:32:10 Mens. 3 3. 1:38:07 Mens. 2 4. 1:42:00 Mens.4 ... return value true 4. timeToHappen += period Describe spatial structure latency > 6 years Describe temporal structure Deforesting Newly implanted Year of creation Iddle Slowing down Deforestation = 100% Describe rules of behaviour Describe spatial relations Governing the commons? Deforestation in Amazonia ~230 scenes Landsat/year How could Brazil reduce deforestation from 27.000 km2 to 7.000 km2 in 5 years? Institutional analysis in Amazonia Identify different agents and try to model their actions Farms Settlements 10 to 20 anos Recent Settlements (less than 4 years) Source: Escada, 2003 Old Settlements (more than 20 years) Amazonia: multiscale analysis of land change and beef and milk market chains with TerraME São Felix do Xingu INPE/PRODES 2003/2004: Deforestation Forest Non-forest Clouds/no data Model development by Ana Paula Aguiar and Sergio Costa (INPE), using TerraME software, built by Tiago Carneiro (UFOP) and Pedro Andrade (INPE) Agents example: small farmers in Amazonia Settlement/ invaded land Sustainability path (alternative uses, technology) Diversify use money surplus Subsistence agriculture Create pasture/ Deforest Manage cattle bad land management Move towards the frontier Sustainability path (technology) Abandon/Sell the property Buy new land Speculator/ large/small Agents example: large farmers in Amazonia Diversify use money surplus/bank loan Buy land from small farmers Create pasture/ plantation/ deforest Manage cattle/ plantation Buy new land Buy calves from small Speculator/ large/small Landscape model: different rules for two main types of agents Beef and milk market chain model Land use Change model Small farmers Medium and large farmers Landscape metrics model Pasture degradation model Several workshops in 2007 to define model rules and variables Landscape model: different rules of behavior at different partitions which also change in time SÃO FÉLIX DO XINGU - 2006 FRONT FRENTE MIDDLE MEIO BACK RETAGUARDA Forest River Deforest Not Forest Modeling results 97 to 2006 Observed 97 to 2006 Modelling collective spatial actions: some potential GIScience contributions 1. 2. 3. 4. Situated individuals (persons, groups, agents): spatial cognition, spatial analysis, scale in GIS Interaction rules: semantics of communication, mobile computing Decision rules: ontology [of actions, events and processes], spatial analysis Properties of space: spatial analysis, spatial databases, scale, uncertainty, vagueness Conclusion GlScience can make a significant contribution to global change research, supporting spatially explicit models of humanenvironment interactions with reasoned scientific basis