Inequity Aversion, Risk Aversion and Strategic Uncertainty in Public Good Games∗

This paper analyzes which type of individuals’ characteristics drive behaviors in a public good game, depending on strategic uncertainty. The results of the laboratory experiment emphasize that advantageous inequity aversion has a significant effect on the contribution decision but beliefs on the others’ contribution and risk aversion are the characteristics that mainly lead the contribution decision under strategic uncertainty. When strategic uncertainty is removed, the reciprocal behavior of individuals is essentially driven by advantageous inequity aversion, as suggested by Fehr and Schmidt (1999). Disadvantageous inequity aversion has no effect neither on the contribution decision nor on the reciprocal behavior. Our results underline the importance of strategic uncertainty to correctly understand cooperation in voluntary contribution mechanisms. They moreover suggest that behaviors of individuals are consistent between different experimental games. They are therefore in favor of within-subjects analyses. JEL classification: C72, C91, D63, D81, H41.