Cooperation in viscous populations - experimental evidence

Grimm V, Mengel F (2009)

Publication Language: English

Publication Type: Journal article

Publication year: 2009


Publisher: Elsevier

Book Volume: 66

Pages Range: 202–220

Journal Issue: 1


DOI: 10.1016/j.geb.2008.05.005


We experimentally investigate the effect of population viscosity (an increased probability to interact with others of one's type or group) on cooperation in a standard prisoner's dilemma environment. Subjects can repeatedly choose between two groups that differ in the defector gain in the associated prisoner's dilemma. Choosing into the group with the smaller defector-gain can signal one's willingness to cooperate. We find that viscosity produces an endogenous sorting of cooperators and defectors and persistently high rates of cooperation. Higher viscosity leads to a sharp increase in overall cooperation rates and in addition positively affects the subjects' preferences for cooperation.

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Grimm, V., & Mengel, F. (2009). Cooperation in viscous populations - experimental evidence. Games and Economic Behavior, 66(1), 202–220.


Grimm, Veronika, and Friederike Mengel. "Cooperation in viscous populations - experimental evidence." Games and Economic Behavior 66.1 (2009): 202–220.

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