Existence and stability results on the unilateral support equilibrium

In this paper, we consider non-cooperative games where each player has an other-regarding behavior. In particular, we study the unilateral support equilibrium introduced by Schouten et al. (2019). A strategy profile is a unilateral support equilibrium if each player’s strategy maximizes the payoff of each other when the opponents do not deviate from their equilibrium strategies. We give necessary and sufficient conditions for the existence of unilateral support equilibria in games where players have discontinuous and non necessarily ordered preferences. Moreover, we study the stability of equilibria when the players partially support the others or perturbations on players’ preferences occur.