Social Capital and Social Quilts: Network Patterns of Favor Exchange
研究了在个体间互动频率低时，如何通过社会压力维持人情交换，发现稳定网络需满足“支持”条件，即交换双方有共同朋友，并在印度农村数据中验证了该模式。
We examine the informal exchange of favors in societies such that any two individuals interact too infrequently to sustain exchange, but such that the social pressure of the possible loss of multiple relationships can sustain exchange. Patterns of exchange that are locally enforceable and renegotiation-proof necessitate that all links are “supported”: any two individuals exchanging favors have a common friend. In symmetric settings, such robust networks are “social quilts”: tree-like unions of completely connected subnetworks. Examining favor exchange networks in 75 villages in rural India, we find high levels of support and identify characteristics that correlate with support.