The peer effect in adverse selection: Evidence from the micro health insurance market in Pakistan
利用巴基斯坦微型健康保险项目数据，研究发现同一社交网络内保险续保决策存在同伴效应，且同风险类型家庭间的效应更强，从而放大了逆向选择。建议对大型团体实施至少60%的最低团体参保率要求以缓解该效应。
Abstract The peer effect may amplify adverse selection in social networks, hampering the sustainable operation of microinsurance. This paper uses data from a micro health insurance program in Pakistan to test for the peer effect in renewal decisions and the role it plays in amplifying adverse selection within social networks. The paper finds evidence supporting that insurance renewal decisions are similar among peers in the same network, and the peer effect is stronger among households of the same risk type than households of different risk types, indicating that the heterogeneous peer effect acts as an amplifier for adverse selection. The paper provides policy implications for effective ways to mitigate the peer effect and adverse selection, based on the results of heterogeneity analyses. The policy recommendation is to enforce a minimum group enrollment rate requirement of at least 60% for large groups to mitigate the peer effect.