Moral Hazard and Lack of Commitment in Dynamic Economies

We revisit the role of limited commitment in a dynamic risk-sharing setting with private information. We show that a Markov-perfect equilibrium, in which agent and insurer cannot commit beyond the current period, and an infinitely-long contract to which only the insurer can commit, implement identical consumption, effort and welfare outcomes. Unlike contracts with full commitment by the insurer, Markov-perfect contracts feature non-trivial and determinate asset dynamics. Numerically, we show that Markov-perfect contracts provide sizable insurance, especially at low asset levels, and are able to explain a significant part of wealth inequality beyond what can be explained by self-insurance. The welfare gains from resolving the commitment friction are larger than those from resolving the moral hazard problem at low asset levels, while the opposite holds for high asset levels.