政府与社会资本合作（Public-Private Partnership，PPP）作为基础设施和公共服务供给的投融资模式，在世界范围内得到广泛运用，并成为我国公共项目建设重要的投融资方式。根据全国PPP综合信息平台显示，截至2017年12月底，我国共计PPP项目14424个，总投资额达18.2万亿元。PPP项目在加快公共物品的供给侧结构性改革，促进经济和政府职能转型被赋予重要功能。

PPP显著的特点之一是政府（一般是地方政府，下同）和社会资本间长期紧密的合作关系，进而导致特殊的政企关系。在这种特殊的政企关系中，企业一方面可能因为与政府的特殊关联而在资源获取方面获得便利，另一方面，企业可能会因为政府的过度干预而失去市场化效率，甚至利益受到严重侵害。因此，在具体的PPP项目中，企业价值目标的实现不仅取决于项目建设与运营效率，还取决于政府与企业之间的行为方式与博弈关系，PPP项目为研究政企关系以及政府干预对企业价值的影响提供了新场景和新视角。

与此同时，PPP项目对参与其中的政府和企业之间的契约关系以各自的风险和收益有重大约定，因此对双方行为及其经济后果具有直接的影响。然而作为PPP项目能否成功实施的重要参与方，企业参加PPP项目的积极性以及行为特性是否符合市场效率原则成为了PPP制度健康发展的重要基础。如果企业参与PPP项目不能获得足够的权益保障，企业参与PPP项目的积极性就不高，影响PPP项目的发展。由于PPP模式中特殊的政企关系，也可能会导致企业行为异化，通过非市场的方式来追求政府关联，获取非市场化利益，则会降低财政与金融效率，加大系统性金融风险。

因此，研究企业参与PPP项目的经济后果，对于深入理解上述问题至关重要，不仅关系到PPP制度的建设和PPP实践的健康发展，还关系到我国系统性金融风险的防范与治理，同时对于深入认识政企关系及企业的非市场化行为动机具有重要意义。基于此，本文从企业角度出发，立足中国独特的制度背景与市场环境，利用手工搜集的企业参与PPP项目数据，对企业参与PPP项目的经济后果，尤其对于企业价值方面影响后果展开理论与实证研究。并在研究结论的基础上，提出相关的政策建议。

本文的研究内容主要包括以下三个部分：

第一，本文首先从PPP项目的国际经验和中国实践介绍了PPP发展的制度背景，在此基础上对PPP项目的国内外研究现状进行系统梳理和回顾，并介绍了PPP项目及其经济后果的理论基础，将其与本文研究问题相结合，阐述企业参与PPP项目产生的经济后果及内在机理。进一步地，基于Iossa和Martimort（2015）、龚强等（2019）的研究，介绍了PPP项目中存在的主要激励问题及其契约关系。

第二，本文分别从PPP项目特征、政府干预和政治关联的角度，实证检验了企业参与PPP项目在其财务层面的经济后果，主要包括市场化的融资成本和非市场化的政策资源获取。结果表明：（1）企业参与PPP项目会显著提高其权益资本成本，且这一正相关性在非国有企业、面临较高的环境不确定性及融资约束的企业以及法律环境和投资者保护水平更差的地区中更加显著。企业风险上升是导致这一结果的主要原因，而企业提高自身信息披露质量能够有效降低参与PPP项目与权益资本成本间的正相关性。（2）企业参与PPP项目能够显著降低其债务成本，且二者间的负相关关系在非国有企业和国有银行中更为显著。没有证据表明企业参与PPP项目后债务资本成本的降低是由于企业稳健性或企业绩效改善带来的，而企业通过PPP项目建立的良好政企关系或政治联系可能是参与PPP项目降低企业债务成本的原因。（3）企业参与PPP项目有助于其获得更多的政府补贴和税收优惠，且这一关系在非国有企业、制度环境更差的地区更加显著。而地方政府晋升压力是导致国有企业参与PPP项目的重要原因。

第三，在理论分析和实证研究的基础上，本文对中国PPP的发展提出了相应建议。主要包括监管部门应该建立相应的信息披露制度和地方政府信用约束机制；地方政府应进一步完善项目事前设计、加强对PPP项目筛选和管理机制；企业应该正确处理PPP项目中的风险和收益，权衡项目风险、政府干预和政治关联对企业的综合影响，树立合作共赢的理念，勇于承担社会责任。

As an investment and financing mode for infrastructure and public service supply, Public-Private Partnership (hereafter PPP) has been widely used in the world and has gradually become an important source of funds for public project construction in China. At the end of December 2017, there were 14,059 PPP projects across the country, with a total investment of 18.2 trillion yuan. It is of great significance to accelerate the supply-side structural reform of public goods and promote the transformation of economy and government functions.

One of the notable features of PPP projects is the long-term close cooperative relationship between the government (usually the local government) and enterprises, which leads to the special relationship between them. On the one hand, enterprises may gain convenience in resource acquisition due to their special relationship with the government; but on the other hand, enterprises may lose market efficiency or even suffer serious damage to their interests due to the excessive intervention of the government. Therefore, the realization of enterprise value objectives depends not only on efficiency of the project, but also on the behavior and game relationship between the government and enterprises. PPP provides a new scenario and a new perspective for the study of the relationship between the government and the enterprise, and the impact of government intervention on enterprises.

At the same time, PPP has a significant agreement on the contractual relationship between the government and participating enterprises with their respective risks and benefits, so it has a direct impact on the behaviors and economic consequences of both parties. However, as an important participant in the implementation of PPP, the enthusiasm of enterprises to participate in projects and whether their behavior characteristics conform to the principle of market efficiency have become an important basis for the healthy development of PPP. If enterprises cannot obtain sufficient protection of their rights and interests by participating in PPP, their enthusiasm will not be high, which will affect the development of PPP. Due to the special relationship between the government and enterprise in PPP, the behavior of enterprises may be alienated. They may pursue the government connection through non-market means to obtain non-market benefits, but this will reduce the fiscal and financial efficiency and increase the systemic financial risks.

Therefore, studying the economic consequences of enterprises' participation in PPP is crucial to a deeper understanding of the above issues. This is not only related to the construction and the healthy development of PPP, but also related to the prevention and governance of systemic financial risks in China. Meanwhile, it is of great significance to deeply understand the relationship between the government and enterprise and the motivation of enterprises' non-market behavior. Based on this, under the unique institutional background and market environment of China, this paper conducts theoretical and empirical studies on the economic consequences of enterprises' participation in PPP, especially on the impact of enterprise value, by using the manually collected data of listed companies' participation in PPP. On the basis of the research conclusions, this paper puts forward some suggestions for the development of PPP in China.

The research content of this paper mainly includes the following three parts:

First, this paper introduces the system background of the development of PPP by introducing the international experience and Chinese practice, then systematically summarizes and reviews the research status of PPP at home and abroad. Besides, it introduces the theoretical basis of PPP project and its economic consequences, combines it with the research problems in this paper, and expounds the economic consequences and internal mechanism of enterprises' participation in PPP. Further, based on the research of Iossa and Martimort (2015), Qiang G et al. (2019), it introduces the main incentive problems and their contractual relationship in PPP.

Second, this paper empirically examines the economic consequences of enterprises' participation in PPP at the financial level from the perspectives of the characteristics of PPP projects, government intervention and political connection, mainly including market-oriented financing costs and non-market-oriented policy resource acquisition. The main conclusions are as follows: (1) participation in PPP projects will significantly increase the cost of equity of enterprises, and this positive correlation is more significant in non-state-owned enterprises, enterprises with high environmental uncertainty, strong financing constraints, areas with poor legal environment and low level of investor protection. The increase in risks of enterprises is the main reason for this result, and the improvement of the quality of information disclosure can effectively reduce the positive correlation between participation in PPP and the cost of equity. (2) participation in PPP projects will significantly reduce the cost of debt of enterprises, and this relationship is more significant in non-state-owned enterprises and state-owned banks. There is no evidence that the decline in the cost of debt is due to the improvement of accounting conservatism or corporate performance, while the government-enterprise relationship or political connection established by enterprises through PPP projects may be the reason why participating in PPP projects reduces the debt cost of enterprises. (3) participation in PPP projects helps enterprises to obtain more government subsidies and tax preferences, and this relationship is more significant in non-state-owned enterprises and areas with worse institutional environment. And the promotion pressure of local government is an important reason for state-owned enterprises to participate in PPP projects.

Third, on the basis of theoretical analysis and empirical research, this paper puts forward corresponding suggestions for the development of PPP in China. It mainly includes that the supervision department should establish the corresponding information disclosure system and the restraint mechanism of the local government; Local governments should further improve the project design in advance and strengthen the selection and management mechanism of PPP projects. Enterprises should correctly trade-off the risks and benefits of PPP projects, weigh the comprehensive impact of project risks, government intervention and political connections, establish the concept of win-win cooperation and have the courage to shoulder social responsibilities.