The Punisher's Dilemma: Uncertainty and the Coexistence of Motivations in Social Dilemmas

Abstract

This study uses uncertainty in the payoff function of a public goods game to distinguish between different motivations for imposing costly punishments in social dilemma situations, specifically highlighting the coexistence of these motivations. There are two possible motivations: reciprocity and inequality aversion. By introducing uncertainty, participants are prevented from predicting others’ contributions based solely on their payoffs. In this situation, participants must choose between others’ contributions and others’ payoffs as the criteria for punishment. Our results reveal heterogeneity in punishment motivations, leading to the identification of different types of punishers: the self-interested type, the reciprocal type, the inequality-averse type, and the“other”type, who exhibits inconsistency. Additionally, the reciprocal type strongly punishes free-riding behaviors while also imposing some punishment for payoff inequality. These findings highlight that inequality aversion is a critical motivation for punishment―some individuals rely solely on inequality aversion, while others incorporate it into their punishment based on reciprocity. Notably, payoff inequality appears to play a crucial role in motivating punishment under uncertainty, regardless of the norm of cooperation.