Debt contracts and cooperative improvements

In this paper, we consider a dynamic game with imperfect information between a borrower and lender who must write a contract to produce a consumption good. In order to analyze the game, we introduce the concept of a coalitional perfect Bayesian Nash equilibrium (cPBNE). We prove that equilibria exist and are efficient in a precise sense, and that deterministic contracts that resemble debt are optimal for a general class of economies. The cPBNE solution concept captures both the non-cooperative aspect of firm liquidation and the cooperative aspect of renegotiation.