Exogenous Variation of Endowments and Beliefs in a Dictator Game

We study sharing in a dictator game with asymmetrically observed random initial allocations. The design exogenously varies both the opportunity cost of sharing and the probability of receiving one of two possible endowment realizations. The treatment successfully shifts recipients' first-order beliefs and dictators' second-order beliefs. We interpret behavior through two channels: a belief-independent equal-sharing norm and a belief-dependent guilt-aversion motive. Conditional on the high-endowment realization, sharing is higher in the high-expectations treatment, consistent with guilt aversion. Overall, the evidence suggests that prosocial behavior reflects both norm compliance and concerns about disappointing others.