近年来，伴随着我国经济的高速发展和我国上市公司融资需求的不断增强， 股权质押在资本市场上愈演愈烈。股权质押可以将控股股东持有的静态资产转 化为可支配流动资金，在受到股东的追捧的同时也存在价值下跌被平仓的风险。 控股股东发生股权质押行为后，“控制权”和“现金流权”两权分离，“侵占”动 机以及控股股东能够实质性影响公司决策的天然优势相互作用，加剧了上市公 司非效率投资。现有研究关于股权质押的文献大都局限于对企业绩效或创新的 研究，对投资行为的研究稍显不足。另一方面，为了抑制非效率投资的发生，提 高公司治理水平显得尤为必要。因此本文将企业非效率投资引入到股权质押影 响企业经济后果的研究框架中，同时考察公司治理在其中的调节作用。 基于上述背景，本文运用文献研究法、规范研究法以及实证研究法，分析股 权质押、公司治理与非效率投资之间的关系。以2014-2018年深沪A股存在股 权质押的公司样本数据为基础，构建实证模型分析三者之间的关联关系，并分别 从股东治理、董事会治理和监事会治理三个维度实证检验了公司治理对股权质 押与非效率投资的调节作用。其中监事会治理在稳健性检验中作为公司治理的 替代变量与股权质押、非效率投资进行回归检验。研究发现：股权质押比例越高， 非效率投资现象越为严峻；公司治理水平越高，企业的非效率投资越能得到抑制； 公司治理对股权质押和非效率投资存在负向调节作用。在此基础上，进一步探讨 了公司治理的调节作用在不同产权性质和负债水平的公司之间影响有何不同。 本文的贡献之处在于：（1）从研究内容和模型应用上，将股权质押、公司治 理与企业的投资活动联系起来，丰富非效率投资影响因素方面的研究。（2）考虑 到我国特殊的经济体制以及负债水平不同对企业非效率投资的影响，进行分组 讨论，提高了研究的针对性和准确性。（3）考虑股权质押活动这一融资行为与企 业投资行为两者之间可能存在的内生性，除去对面板数据进行传统回归之外，进 行稳健性检验，提升实证结果的可信度。本文研究丰富了股权质押和非效率投资 的研究成果，提供了新的研究视角，而且为企业提高公司治理水平和投资决策的 有效性提供了更丰富的理论支持和实证依据。 关键词：股权质押，非效率投资，公司治理，产权性质 II Abstract In recent years, with the rapid development of China's economy and the increasing needs of enterprises for financing, share pledge has become increasingly fierce in the capital market. As a new financing method, share pledge can transform the static assets held by the controlling shareholders into available dynamic capital, which is not only popular with the shareholders, but also has the risk of value drop being liquidated. After the pledge of share by the controlling shareholder, the separation of "control right" and "cash flow right", the "motive of encroachment" and the natural advantage that the controlling shareholder can effectively influence the company's decision have aggravated the inefficient investment of the listed company. The existing literature on share pledge is mostly limited to the study of enterprise performance or innovation, and the research on investment behavior is somewhat insufficient. On the other hand, in order to restrain the occurrence of inefficient investment, it is particularly necessary to improve the level of corporate governance. Therefore, this thesis introduces the inefficient investment of enterprises into the research framework of the impact of share pledge on the economic consequences of enterprises and investigates the regulatory role of corporate governance. Based on the above background, this thesis uses literature research, normative research and empirical research to analyze the relationship between share pledge, corporate governance and inefficient investment. Based on the sample data of listed companies with share pledge behavior in A-shares of Shenzhen and Shanghai from 2014 to 2018, an empirical model was constructed to analyze the correlation among this three, and the regulatory effect of corporate governance on share pledge and inefficient investment was empirically tested from three dimensions of shareholder governance, board governance and board of supervisors governance. Among them, the governance of the board of supervisors in the robustness test as a substitute variable of corporate governance and share pledge, inefficient investment regression test and analysis. It is found that the larger the proportion of share pledge, the more serious the inefficient investment is. The higher the level of corporate governance, the more the III inefficient investment can be restrained. Corporate governance has a negative regulating effect on share pledge and inefficient investment. On this basis, the author further discusses the different effects of corporate governance regulation on companies with different property rights and debt levels. The contribution of this thesis is as follows :(1) from the research content and model application, it links share pledge, corporate governance and enterprise investment activities to enrich the research on influencing factors of inefficient investment. (2) considering the impact of China's special economic system and different debt levels on inefficient investment of enterprises, the group discussion was conducted to improve the pertinence and accuracy of the research. (3) considering the possible endogenicity between the financing behavior of share pledge and the enterprise investment behavior, besides the traditional regression of the panel data, the robustness test is carried out to improve the credibility of the empirical results. This thesis enriches the research results of share pledge and inefficient investment, provides a new research perspective, and provides a richer theoretical support and empirical basis for enterprises to improve the level of corporate governance and the effectiveness of investment decisions. Keywords: Share pledge；Non-efficient investment；Corporate governance；Property nature IV 目录 摘要 ....................................................................................................................... I Abstract .............................................................................................................. II 第1章 绪论 ......................................................................................................... 1 1.1 研究目的及意义 .................................................................................... 1 1.1.1 研究目的 ..................................................................................... 1 1.1.2 研究意义 ..................................................................................... 3 1.2 国内外研究现状 .................................................................................... 4 1.2.1 股权质押相关文献 ..................................................................... 4 1.2.2 非效率投资的文献综述 ............................................................. 6 1.2.3 公司治理调节作用的文献综述 ................................................. 7 1.2.4 研究现状述评 ............................................................................. 8 1.3 研究内容与方法 .................................................................................... 9 1.3.1 研究内容 ..................................................................................... 9 1.3.2 研究方法 ................................................................................... 10 第2章 概念界定与理论基础 ......................................................................... 12 2.1 概念界定 .............................................................................................. 12 2.1.1 企业非效率投资 ....................................................................... 12 2.1.2 股权质押 ................................................................................... 13 2.1.3 公司治理 ................................................................................... 14 2.2 基本理论 .............................................................................................. 15 2.2.1 委托代理理论 ........................................................................... 15 2.2.2 信息不对称理论 ....................................................................... 16 2.2.3 融资约束假说 .........................................