Renegotiation of Sales Contracts
研究代理人选择不可观测努力后可能重新谈判的道德风险合同，发现所有均衡都是次优有效的，且当努力集丰富时，唯一均衡初始合同是销售合同。
This paper studies moral hazard contracts that may be renegotiated after an agent chooses an unobservable effort. Unlike in previous models, a contract here contains only one compensation scheme, and the agent has all the bargaining power in the renegotiation stage. Using a relatively weak forward-induction refinement, all equilibria are shown tb be (second-best) efficient. Renegotiation occurs in every equilibrium. If the effort set is rich, the only equilibrium initial contract is a sales contract, i.e., a scheme which sells the project to the agent. This captures the idea that a party (the principal) who has an inherently weak renegotiation position will sometimes insist on a simple initial contract.