Guilt Aversion in (New) Games: the Role of Vulnerability

From the literature we know that contextual factors modulate guilt aversion, such as pre-play communication and social closeness. In this study, we investigate whether a particular feature of the game itself = the vulnerability of the co-players = affects a player's guilt aversion. We deem that a co-player is (i) ex-post vulnerable when her final payoff depends on the decision-maker's actions, and (ii) ex-ante vulnerable when the use of her initial endowment depends on the decision-maker's actions. In a laboratory experiment, we introduce four (new) three-player trust games played within-subjects, varying whether the trustees can condition their decision on the belief of another player who is ex-post vulnerable and/or ex-ante vulnerable. We put forward a portable model of lexicographic altruism and role-dependent guilt, where the trustee can only be altruistic toward the most disadvantaged player and can feel guilty simply because of his role in the game. We find that trustees' guilt aversion is insensitive to the opponents' vulnerability and to the role of the vulnerable player.