A Game-Theoretic Model of Coalition Formation Among Primates

Abstract

This paper models the coalition formation process among primates as a sequential game. The population consists of primates having distinct social ranks. The rank of each individual is determined by his resource holding potential. Each member of the population is interested in gaining access to a food resource, either individually or via a coalition. At any given stage of the game, a player can either propose a specific coalition or he can be proposed to in order to join one. Hence, the strategy of a player consists of a sequence of decisions regarding who to propose to for the formation of a coalition and which proposals to accept or reject. We derive the preferences of the players over the various coalition structures under the assumption that the probability of a coalition to obtain the resource is given by a logistic distribution. The distribution depends on the strengths of the players. We show that, given the primates' strategic behavior, a variety of different coalition structures can emerge in equilibrium.

Keywords: subgroups, resource holding potential, rank heirarchy, subgame perfection

JEL Classification: C72, C79