Impact of bridging social capital on the tragedy of the commons: experimental evidence
通过公共池资源实验，研究群体间捐赠行为如何影响资源可持续性，发现个体决策者更愿捐赠但无法阻止资源下降，且低禀赋群体因期待捐赠而过度开采导致公地悲剧。
Abstract Sharing resources between members of different tribes and collectives is common and well-documented. Surprisingly, little is known about factors that are conducive to building social relationships between groups. We design a common-pool resource experiment, where after harvesting, groups can send some of their harvest to augment the resource of the outgroup. We compare donations made by individuals collectively and independently of other group members, under the conditions of equal and unequal resources. We find that individuals acting as decision-makers, but not groups, donate harvests frequently even though it is payoff-reducing. We conduct an additional treatment, where each donation is matched (doubled) by an equivalent transfer of resources, making sharing between groups payoff-improving. Under matching donations, sharing between groups flourishes, but fails to prevent resource decline in most groups. Finally, our experiment reveals that members of low-endowment groups overharvest resources in expectation of donations from affluent groups, which leads to the tragedy of the commons.