Networks and the Diffusion of
Pro-Social Innovations
MARISSA KING
YALE SCHOOL OF MANAGEMENT
Classic S-Shaped Diffusion Curve
Percent Adopted
Time
Rogers. 1995. Diffusion of Innovations
Home PC
Air conditioner
Refrigerator
Cellular Phone
Sources: PC, refrigerator, & cell phone: Lilien 1999; Air conditioner Sulltan 1990;
Framework for Thinking About Endogenous
Diffusion
 Structure

Underlying network
 Product


Simple Contagion
Complex Contagion- Roger’s Five Factors
 Mechanisms


Learning
Possession
 Context

Physical and Social Environment
Same Framework Different Products and Contexts
 Antislavery organizations

King, Marissa and Heather Haveman. 2008. “Antislavery in America: The Press, the Post, and the Pulpit, 17901840.” Administrative Science Quarterly 53:492-528
 Cooperatives in the early 1900s

Schneiberg, Marc, Marissa King and Thomas Smith. 2008. “Social Movements and Organizational Forms: Agrarian
Protest and Cooperative Alternatives to Corporate Hierarchies in Three American Industries.” American
Sociological Review 73:635-667.
 Autism


King, Marissa and Peter Bearman. 2011. “Socioeconomic Status and the Increased Prevalence of Autism in
California. American Sociological Review. 76:320-346.
Liu, Kayuet, Marissa King, and Peter Bearman. 2010. “Social Influence and the Increased Prevalence of Autism
Diagnosis.” American Journal of Sociology. 115: 1387-1434.
 Antidepressants, stimulants, & antipsychotics


King, Marissa, Joseph Ross, Connor Essick, and Peter Bearman. Forthcoming.“Physician Conflicts of Interest and
Psychotropic Prescribing.” BMJ
King, Marissa and Peter Beaman. Conflict of Interest Policies and the Diffusion of Stimulant, Antidepressant, and
Antipsychotic Medications.
*Sanitation facilities, fuel efficient cook stoves, and solar
lanterns in India *
Roadmap
 Overview of framework
 Structure
 Product
 Mechanisms
 Context
 2 Cases
 Potty Project-Sanitation facilities in Bhubansewar
 SEWA Hariyali Project-200,000 Fuel efficient cook stoves and
solar lanterns Breakout
 Conclusion and experimental design
Structure
Social network analysis:
• Both a theory and a method
• Is motivated by a structural intuition based on ties linking actors
• Social world as patterns or regularities among interacting units
• Focuses on how patterns shape behaviors
• Is grounded in systematic empirical data
• Draws heavily on graphic imagery
• Relies on the use of mathematical and/or computational models.
StructureProductMechanismsContext
Structure: Why do Networks Matter?
StructureProductMechanismsContext
Structure: Why do Networks Matter?
StructureProductMechanismsContext
Bearman, Moody, and Stovel 2001
Structure: Strong and Weak Ties
Structural meaning (population level)
• Strong ties produce triadic closure
• Weak ties connect often connect distinct network clusters
• Small worlds
Relational meaning (dyadic)
• Weak ties are acquaintances who you interact with less
frequently
• Weak ties connect otherwise socially distant actors
• Betweeness centrality
• Strong ties are close friends, family, etc. who you likely have
an affective bond with and trust
• Degree centrality
Different types of ties have very different implications
in diffusion processes
StructureProductMechanismsContext
Centrality example: Colorado Springs
Node size proportional to
betweenness centrality
Graph is 27% centralized
Rothenberg et al 1995
StructureProductMechanismsContext
Centrality example: Add Health
Node size proportional to
betweenness centrality
Graph is 45% centralized
Bearman, Moody, and Stovel 2001
Random seeding vs. Influentials
 Influentials- Some individuals have a
disproportionate number of ties
 Social networks tend to be scale-free
and have long right tail
 Targeting influentials best way to
encourage diffusion
 Random Seeding


Identifying influentials is next to
impossible so better off saving the
money/resources you would allocate
to them and randomly seed
Single exposure/endorsement from
one individual not as powerful as
multiple exposures from several
individuals
Slide from Paul Adams “The Real Life Social Network”
But Product Characteristics (What’s Diffusing)
Also Matters….
SIMPLE CONTAGION
• Standard epidemiological models
• Examples include spread of easily transmittable information or disease
that spread through simple contact
• Mass marketing and broadcast diffusion
• Weak ties
COMPLEX CONTAGION
• Behaviors are costly, risky, or controversial, the willingness to participate
may require independent affirmation or reinforcement from multiple
sources
• Successful transmission depends on contact with multiple
carriers/advocates
• Social influence and peer effects
Complex Contagion Requires Social Influence/Peer Effects
StructureProductMechanismsContext
Centola and Macy 2007
Product Characteristics: Roger’s Five Factors
Factor
Definition
Relative Advantage
How improved an innovation is over the
previous generation.
Compatibility
The level of compatibility that an
innovation has to be assimilated into an
individual’s life.
Complexity
If the innovation is perceived as
complicated or difficult to use, an
individual is unlikely to adopt it.
Trialability
How easily an innovation may be
experimented. If a user is able to test an
innovation, the individual will be more
likely to adopt it.
Observability
The extent that an innovation is visible to
others. An innovation that is more visible
will drive communication among the
individual’s peers and personal networks
and will in turn create more positive or
negative reactions.
StructureProductMechanismsContext
Rogers 1995
Mechanisms
 Selection that produces correlated choices must be
ruled out
 Social learning
 Learning by using
 Reduced uncertainty since peer’s consumption
 Possession
 Keeping up with the Jones
 Joint consumption
StructureProductMechanismsContext
Context
If you introduce the same innovation on similar
networks in different contexts do you see different
patterns of diffusion?
• King and Bearman (2011) and King and Bearman (2013)
both found spatial differences in patterns of diffusion
•
•
Socioeconomic status
Regulatory environments
But very few studies examine the diffusion of the
same product in different markets
Framework for Thinking About Diffusion
 Structure

Underlying network
 Product


Simple Contagion
Complex Contagion- Roger’s Five Factors
 Mechanisms


Learning
Possession
 Context

Physical and Social Environment
Case Studies
SEWA Cook Stoves & Lanterns
Potty Project
with Rodrigo Canales & Tony Sheldon
PIs: Sharon Barnhardt, Judy Chevalier, & Mushfiq Mobarak.
With Rodrigo Canales
SEWA: Organization Overview
20
SEWA is a cooperative of low-income, self-employed women
• Mission: organizing women workers for full employment and
self-reliance
• Registered as a trade union since 1972
• Membership of 1,356,000 women across 7 states in India
Slide from Yale GSE SEWA Micro Team
SEWA Hariyali Project
 Problems:
 Women and young children spend up to five hours a day in
smoky kitchens



Lung and eye health problems are common
Women spend hours collecting fuel (wood) for the stoves,.
Use of firewood contributes to deforestation.
 Goal:
 Sell 200,000 cook stoves over three years to clients in 4 states
clients in 4 states (Gujarat, Rajasthan, UP and Bihar)


Bundled with solar lantern
Cook stoves reduce wood requirements and cooktime by ~50%
Obstacles to Adoption
• The targeted Hariyali demographic is highly price
sensitive
•
Rs. 310 per month for 12 months
• Significant behavior change required to switch
from free to paid product
• Health concerns are not sufficiently motivating
factor
Existing Network
 By virtue of SEWA membership already have shared
common identity
 Members of each trade elect own representatives to
 Considerable geographic variation in size
Rajasthan
Bikaner
Bihar
5,035
Dungarpur 3,300
Jaipur
Ajmer
UP
Gujarat
Bareli 402
60.8% Rural
Lucknow 24,100
39.2% Urban
550
100
Jodhpur 183
9, 168
12,0000
24, 502
519,309
Current Sales & Reporting Method
Salesperson visit village and does demonstration,
members raise of hands to signal interest (V, M, O)
Anand
M
V
O
Bodeli
S
%
V
M
O
Surendranagar
S %
V M
O
S
%
Mahesana
V M
O
S %
12
425
47
4
11.05
10 237
9
0
3.79 3 128
1
0
0.78 7 140
10
0
7.14
15
455
53
22
11.64
8 228
0
0
0 7 169
9
5
5.32 8 182
11
0
6.04
13
293
54
24
18.4
11 353
3
0
0.84 9 197
3
3
1.52 6 141
7
0
4.96
20
440
22
13
5
6 154
2
0
1.29 5 149
5
2
3.35 4
71
17
0
23.94
12
250
25
14
10
18 561
1
0
0.17 4
91
2
2
2.19 7 127
8
3
6.29
13
250
13
11
5.2
9 248
0
0
0 0
0
0
0
0 10 173
17
0
9.82
14
260
20
11
7.69
3
64
0
0
0 0
0
0
0
0 13 204
23 22
11.27
17
440
43
36
9.77
18 515
1
0
0.19 0
0
0
0
0 20 415
16 16
3.85
Network Potential
 SEWA already has existing network and information
about network members
 Relatively variability in village size
 Variability in connectedness between villages
 Product characteristics make cook stoves and
lanterns good candidates for diffusion

Visibility and trialability
Potty Project
Diffusion Analysis and Policy Evaluation with Rodrigo Canales
Problem
 45% of households use either public or communal
toilets in the slums of Bhubaneswar and Cuttack
 53% of these toilets are either “dirty” or “very dirty’ &
one was completely non-functional
 Households dissatisfied with the cleanliness were the
most likely to practice open defecation

30% of households reported doing so
Barnhardt, Chevalier & Mobarak
Potty Project
 Gates Foundation commissioned Quicksand Design
Studio to conduct in-depth research into the behaviors,
attitudes, and beliefs surrounding sanitation in lowincome urban India in 10 slums in 5 cities in India.
Photos: Quicksand reprinted in Wall Street Journal
Potty Project
 Based on their research they designed new sanitation
facility prototype
Design: Quicksand reprinted in Wall Street Journal
Potty Project
 Barnhardt, Chevalier & Mobarak are utilizing Quicksand’s
insights in a field experiment
Paid Manager
Cooperative
Management
Improved Facilities Basic
New Facilities Basic
Improved Facilities Enhanced
New Facilities Enhanced
• Basic facilities include adequate gender-separate toilets and washbasins,
sufficient lighting and ventilation & enough water for all services
• Improved facilities will include bathing, child toilets, menstruation waste
• Experiment will also include discount coupons and varying pricing
structure (monthly passes vs. pay-per-use)
Why Networks Matter
Quicksand pottyproject.in
Network Context
 Lots of social cleavages
 Existing networks critical for both initiating use and
creating community ownership to encourage
sustainability
 Old facilities have existing network of users, new
facilities do not
 Network data from household survey
Study Design
SEWA
Context: How much does the importance of social
influence vary by area and population ?
Product: Give loaner cook stoves to seed network
Structure and Mechanisms(?)
Sales Pitch from
Alter
No Sales Pitch
from Alter
Random Seed
Influentials
No Network Seeding
Sales pitch from
outsider
Potty Project
Context: How much does the importance of social influence
vary by area, toilet design, and composition of population ?
Product: Use vouchers for facility (much like drug
companies)
Structure and Mechanisms(?)
Sales Pitch
from Alter
Random Seed
Influentials
No Network Seeding Sales pitch from
outsider
No Sales Pitch
from Alter
Hariyali & Potty Project
Additional research opportunities:
 Product abandonment
 How do networks change after introduction of new
technology?
 Both projects will include extensive fieldwork and
project evaluations
Thanks!