The Fear of Exclusion: Individual Effort when Group Formation is Endogenous*
研究发现，为了保住自己在受欢迎群体中的成员身份，个体会比群体外生形成时贡献更多公共品，而不受欢迎群体则缺乏这种激励，导致群体间努力水平差异，这解释了群体特定行为规范的存在。
Abstract To secure their membership in a popular group, individuals may contribute more to the group's local public good than they would if group formation were exogenous. Those in the most unpopular group do not have this incentive to contribute. This may result in substantial differences in individual effort level between groups. Our model thus provides one explanation for the existence of group‐specific behavioral norms. A principal will prefer exogenous or endogenous group formation depending on whether he prefers high or low levels of the local public good. We analyze two stylized examples: social interaction in schools, and multiple‐task teamwork.