Time as a Medium of Reward in Three Social Preference Experiments

We report results from three well-known experimental paradigms, where we use time, rather than money, as the salient component of subjects’ incentives. The three experiments, commonly employed to study social preferences, are the dictator game, the ultimatum game and the trust game. All subjects in a session earn the same participation fee, but their choices affect the time at which they are permitted to leave the laboratory, with decisions typically associated with greater own payoff translating into an earlier departure. The modal proposal in both the dictator and ultimatum games is an equal split of the waiting time. In the trust game, there is substantial trust and reciprocity. Overall, social preferences are evident in time allocation decisions. Received laboratory results from dictator, ultimatum, and trust games are robust to the change in reward medium, though there is some suggestive evidence that decisions are even more prosocial with respect to time than money