Epistemic Conditions for Equilibrium in Beliefs without Independence

Aumann and Brandenburger [Econometrica 63 (1995), 1161 1180.] provide sufficient conditions on the knowledge of the players in a game for their beliefs to constitute a Nash equilibrium. They assume, among other things, mutual knowledge of rationality. By rationality of a player, it is meant that the action chosen by him maximizes his expected utility, given his beliefs. There is, however, no need to restrict the notion of rationality to expected utility maximization. This paper shows that their result can be generalized to the case where players' preferences over uncertain outcomes belong to a large class of non-expected utility preferences. Journal of Economic Literature Classification Numbers: C72, D81.