On efficiency, tie-breaking rules and role allocation procedures in evolutionary bargaining

We show, in the context of a simple evolutionary bargaining game, that the efficiency of bargaining behavior depends crucially on the tie-breaking rule players use. For certain tie-breaking rules, and in the limit as the number of feasible demands becomes infinite, all the surplus is wasted. Inefficiency arises for any role assignment procedure, as long as there is some probability that two players are assigned to the same role. We also investigate the relationship between bargaining efficiency and spitefulness.