Social Preferences and Strategic Uncertainty: An Experiment on Markets and Contracts

This paper reports experimental evidence on a stylized labor market. The experiment is designed as a sequence of three phases. In the rst two phases, P1 and P2; agents face simple games, which we use to estimate subjects social and reciprocity concerns, together with their beliefs. In the last phase, P3; four principals, who face four teams of two agents, compete by o¤ering agents a contract from a xed menu. Then, each agent selects one of the available contracts (i.e. he "chooses to work" for a principal). Production is determined by the outcome of a simple effort game induced by the chosen contract. We nd that (heterogeneous) social preferences are signi cant determinants of choices in all phases of the experiment. Since the available contracts display a trade-of between fairness and strategic uncertainty, we observe that the latter is a much stronger determinant of choices, for both principals and agents. Finally, we also see that social preferences explain, to a large extent, matching between principals and agents, since agents display a marked propensity to work for principals with similar social preferences