中文摘要：

研究了委托人（业务购买方）对于承包人（业务供应方）生产成本具有非对称信息时的最优合约设计问题．基于委托人视角，给出了委托人如何诱导代理人报告自己真实成本信息的逆向选择模型，并刻画了最优合约的特征．结果表明：给出的合约能够达到诱导代理人讲真话的目的；在信息非对称条件下，委托人由于信息缺乏受到了损失，而低成本类型的代理人获得了额外的信息租金：在非对称信息条件下．最优合约的泰教配琶营到垂托人事前信念的影响．

英文摘要：

This paper focuses on how to design an optimal contract in supply chain outsourcing. Under the framework of information asymmetry that the buyer has asymmetric information about the suppliers＇ production cost, we propose an adverse selection model to reveal the actual cost of suppliers, and then characterize the optimal contracts. The results show that the optimal contracts can motivate the suppliers to reveal their real costs. Further, the analyses indicate that the buyer loses partial profits due to lack of the information and that the supplier with lower-cost can get extra information rents. Finally, the results reveal the optimal contract is affected by the buyer＇ sex ante belief.