Evolutionarily Stable Coalition Structure

Abstract

We analyze the formation andstability of coalitions for a situation where\r\nfinitely many individuals form different coalitions and their payoffs depend on the consequence of a \r\nnoncooperative game with different coalitions， and examine the moving path of individuals among \r\nvarious coalitions. Our main finding is to show that there exists at least one evolutionarily stable \r\ncoalition equilibrium in fnπ . When addressing the evolving path of coalitions， we conclude that in \r\nthe case of symmetric strategies and symmetric population shares， if each coalition`s population \r\nshare is too small， the equilibrium requires a reduction of the number of coalitions， but if each \r\ncoalition share is too large， the equilibrium requires an increase of the number of coalitions. \r\nFurthermore， when ui(.)s are symmetric but x is asymmetric， then (i) the\r\nhighest payoffs are oscillatory across time still stability happens. (ii)In the\r\nevolutionarily stable structure， each group share the same population and the coalition numbers is \r\nhence IDt(x， 1ft)I.