PPP作为一种创新型的公共品供给模式，在我国获得了飞速发展。目前对PPP的学术研究多集中在实务操作层面，对其理论机制的研究则相对滞后，本项目拟弥补这个不足。本项目将对PPP进行详尽的理论机制研究，包括从微观层面上构建以Iossa and Martimort (2015)多阶段任务为基础的政府企业委托代理模型，从中观层面上构建以Zodrow and Mieszkowski (1986)和Wilson (1986)生产资本流动为基础的税收竞争模型，从宏观层面上构建以Barro (1990)内生增长模型为基础的最优税收模型；着重考察不同公共品供给模式对政府和企业合作行为、地区政府之间竞争行为和中央政府决策行为的多层次影响，并进一步对相关理论结论进行相应的案例分析、实证分析和模拟分析。预期本项目的研究结论对理解和指导PPP运作具有显著的现实及政策意义，对拓展PPP的文献研究也存在突出的理论意义。

Public-private partnership (PPP), as an innovative mode of public goods provision, has been widely adopted in China. However, the existing research on PPP is concentrated on the practical operation issues, while the theoretical mechanism behind PPP is almost overlooked. This project will fill in this gap. Our research is designed to investigate theoretical mechanisms of PPP. We plan to build up a micro level principal-agent model based on multi-stage tasks (Iossa and Martimort, 2015), a medium level tax competition model with mobile productive capital (Zodrow and Mieszkowski, 1986 and Wilson, 1986), and a macro level optimal taxation model based on endogenous growth model (Barro, 1990) respectively, to explore the multi-level influences of different modes of public goods provision on the cooperative behavior between governments and private enterprises, the competition among local governments, and the decision-making behavior of the central government. In order to test the theoretical predictions, we will further carry out case studies, and use local and macro data to conduct empirical and simulation analyses. Our research will make original contributions to the literature of PPP. Moreover, our theoretical and empirical researches have important policy implications, which will shed new lights on understanding PPP operations.