Social identity and the formation of health insurance networks.

In a panel survey of an informal insurance network in Tanzania we find none of the tell-tale signs that insurance transfers follow reciprocal risk sharing arrangements among selfinterested individuals: insurance remittances do not occur through informal loans; transfers are not regressive; and they do not fall when shocks are repeated over time. The evidence of unreciprocated transfers occurring between kin is suggestive of risk sharing based on altruism or social norms