中文摘要：

PPP模式能够满足公共基础设施需求,有效改善政府大量负债现象、促进管理效率提高,因而成为各国在基础设施方面广泛采用的方法。然而在PPP项目合同执行过程中,不可避免要发生再谈判,影响了PPP合同执行效率。本文分析了PPP项目再谈判的文献,得出如下结论：再谈判现象的影响因素主要划分为不完备合同、机会主义行为以及外部环境变化i再谈判行为既可能导致合作提升项目价值,也可能导致政府或者公众利益受损,进而减少社会剩余;治理再谈判主要是完善合同规制和外部规制,增强基于关系契约的沟通、信任等能促进再谈判向着合作方面发展,提升项目价值。最后,本文提出改善PPP合同绩效的措施。

英文摘要：

PPP model has been widely used for providing infrastructure services by many countries in the world because of meeting the needs of the public,decreasing liability of government and improving the efficiency of the government.However,in the process of the implementation of the PPP project contract,renegotiation is inevitable and will affect the efficiency of PPP contract execution.The literatures of renegotiating PPP contract are reviewed and conclusion could be drawn.The main determinants of renegotiation are incomplete contract,opportunistic behavior and external environment change.And renegotiation may increase project value though cooperation,and may cause to damage of government or private interest,thereby reducing social surplus。 The governance measures of renegotiation include improvement of contract regulation and external regulation,and establishment of communication,trust based on relational contract.At last,the suggestions are proposed on how to improve the contract performance of PPP.