Renegotiation of Sales Contracts.

This paper studies moral hazard contracts that may be renegotiated after an agent chooses an unobservable effort. Unlike in previous models, a contract contains just one scheme and the agent has the renegotiation bargaining power. All equilibria satisfying a weak forward-induction refinement are shown to be (second-best) efficient. Renegotiation necessarily occurs. If the effort set is rich, the initial contract must be a sales contract 'selling the project' to the agent. Thus, a party (the principal) who has an inherently weak renegotiation position should sometimes insist on a simple initial contract. Copyright 1995 by The Econometric Society.