In this paper I study conditions for the emergence of cooperative behavior in a dynamic model of population interaction. The model has finitely many individuals located on a circle. The pay- off of each individual is partly based on the (local) interaction with neighbors and partly on (uniform) interaction with the whole population. The dynamics is driven by imitative behavior. I show that for a large class of parameters cooperation will emerge if the population is large; if the population is small, defection will prevail in the long run. The result contrasts with conventional wisdom which says that the larger the population, the less likely cooperation will be.

cooperation, evolutionary game theory, local interaction, prisoner's dilemma
Noncooperative Games (jel C72), Externalities (jel D62)
Tinbergen Institute Discussion Paper Series
Tinbergen Institute

Janssen, M.C.W. (2000). Imitation of Cooperation in Prisoner's Dilemma Games with Some Local Interaction (No. TI 00-019/1). Tinbergen Institute Discussion Paper Series. Retrieved from