Homophily in Peer Groups
研究了同伴群体如何内生形成，发现稳定群体必须足够同质，并分析了群体规模增大时异质性持续的条件。对理解群体偏好构成与贡献类型的关系有帮助。
The focus of this paper is the endogenous formation of peer groups. In our model, agents choose peers before making contributions to public projects, and they differ in how much they value one project relative to another. Thus, the group's preference composition affects the type of contributions made. We characterize stable groups and find that they must be sufficiently homogeneous. We also provide conditions for some heterogeneity to persist as the group size grows large. In an application in which the projects entail information collection and sharing within the group, stability requires more similarity among extremists than among moderate individuals.