Evolution of cooperation
Gilberto Câmara, Earth System Science Center, INPE
Licence: Creative Commons By Attribution Non Commercial Share Alike
http://creativecommons.org/licenses/by-nc-sa/2.5/
Acknowledgments for using previous material
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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
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
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
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
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Survey
Moran, “Environmental Social Science: Human-Environment Interactions and
Sustainability” (2010)
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Social simulation
Schelling, “Micromotives and macrobehavior” (1978).
Batty, “Cities and complexity” (2005).
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Game theory
von Neumann and Morgenstern, “Theory of games and economic behavior” (1944)
Nash, "Equilibrium points in n-person games“ (1950).
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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).
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Institutional analysis
Ostrom, “Governing the commons” (1990).
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…”
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.
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.”
Conclusion
Spatial models of human-environment interactions can support
the study of common pool resources