The peer effect in adverse selection: Evidence from the micro health insurance market in Pakistan

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.