Common Incentives, Unequal Gains: Global Evidence from Public-Goods Experiments

Can common institutions produce different gains from cooperation across culturally diverse environments? We address this question using standardized repeated public-goods experiments, with and without punishment, in 43 diverse countries (n = 3, 876). The design permits direct comparison of voluntary cooperation, conditional cooperation, peer-enforced cooperation, and punishment behavior under identical incentives. We document large cross-societal differences: realized cooperation gains vary by 81 percentage points between the highest- and lowest-gain subject pools. We interpret these patterns through a belief-based model: everyday experiences of cooperation shape expectations about others’ cooperation and the use of punishment. Consistent with model predictions, cooperation and punishment correlate with a cross-country Cooperative Environment Index. Mechanism experiments (n = 1, 092) exogenously vary exposure to strong enforcement. This exposure raises later beliefs and cooperation after enforcement is removed. Together, the findings provide evidence that common institutions can generate unequal gains because their effectiveness depends on expectations about cooperation and its enforcement.