I 摘要 2010年3月31我国证券市场开始实行融资融券制度意味着我国正式引入了卖空 机制。在此之前，我国证券市场只能够进行做多，即通过杠杆融资的方式投资未来前景 看好的股票。在引入融券卖空的交易制度后，投资者可以通过发掘融资融券标的公司 的负面信息，对于未来前景不好的公司进行融券卖空，并从中获利。卖空机制所导致公 司股价下跌的压力会对管理层经营管理行为造成直接影响。现代公司制中所有权与经 营权分离导致的代理问题普遍存在，长久以来，人们为了解决代理问题对公司内部治 理进行了广泛研究，而卖空机制作为证券市场的基本交易制度，正好在解决内部人管 理问题发挥了外部治理作用。在国外，卖空机制的研究较为丰富。但我国从卖空机制引 入实施至今时间不长，虽然已有学者对融资融券制度进行过一些研究，但从卖空机制 在发挥上市公司外部治理作用的研究还相当缺乏。 因此，本文基于契约理论、信息不对称理论和委托代理理论的基本内容，选择沪深 两市的融券标的公司为研究对象，研究了自我国融券卖空机制推出至今，融券卖空对 上市公司盈余管理行为的影响，进一步探讨了股权结构在其中发挥的调节作用。研究 结果发现，上市公司融券卖空与盈余管理之间存在负相关关系，即我国证券市场融券 卖空制度在一定程度上抑制了上市公司盈余管理的行为，发挥了公司外部治理作用， 而股权集中度弱化了二者之间的负相关关系，股权制衡度、机构投资者持股以及国有 股权性质能够强化二者的负相关关系。最后，本文针对我国主板市场中融券卖空相关 制度建设、融资融券的监管以及上市公司的内部股权结构提出了优化融券卖空交易制 度的对策建议，以促进融券卖空的外部治理作用的发挥。 关 键 词：融券卖空；盈余管理；股权结构 论文类型：应用研究 ABSTRACT II ABSTRACT China's securities market began to implement the financing and margin system since March 31th 2010 , which means that China officially introduced the short selling mechanism. Short selling mechanism has a negative impact on listed companies in the stock price, and this external pressure is bound to have a direct impact on the behavior of the company's management. Short selling mechanism plays an external role in solving problem of agency. Although some scholars has done some research it, but the short selling mechanism in the role of external governance of listed companies is still quite lacking. Therefore, based on the basic content of agency theory, contract theory and information asymmetry theory, this paper selects the companies of the securities trading target in Shanghai and Shenzhen as the research object, and studies the influence of short-selling on the earnings management behavior of listed companies, further exploring the internal governance mechanism of the equity structure in which the role of regulation. The results show that there is a negative correlation between short selling and earnings management of listed companies, that is, the short-selling system of securities market in China has inhibited the behavior of earnings management playing the role of external governance of the company. The concentration of equity weakens the negative correlation between the two, the degree of equity checks and balances, the equity checks and balances. The negative correlation between institutional investors' shareholdings and the nature of state-owned equity can strengthen the negative correlation between the two. Finally, this paper puts forward some countermeasures to optimize the short-selling system of margin securities in the security market, the supervision of margin trading and the internal equity structure of listed companies, so as to promote the further development of the external governance role of short-selling securities. KEY WORDS: Short selling of margin securities;Earnings management;Equity structure TYPE OF THESIS: Application Research 目 录 III 目 录 摘要 ............................................................................................................................................................ I ABSTRACT ...................................................................................................................................................... II 1 绪论 ........................................................................................................................................................... 1 1.1研究背景 ............................................................................................................................................ 1 1.2 研究意义 ........................................................................................................................................... 2 1.2.1理论意义 ..................................................................................................................................... 2 1.2.2 现实意义 .................................................................................................................................... 3 1.3 研究思路 ........................................................................................................................................... 3 1.4 研究内容 ........................................................................................................................................... 5 1.5 主要创新点 ....................................................................................................................................... 5 2 文献综述与理论基础 ............................................................................................................................... 7 2.1 文献综述 ........................................................................................................................................... 7 2.1.1 盈余管理的相关研究 ................................................................................................................ 7 2.1.2 股权结构的相关研究 ................................................................................................................ 9 2.1.3 卖空机制的相关研究 .............................................................................................................. 11 2.1.4 文献综述 .................................................................................................................................. 13 2.2 理论基础 ......................................................................................................................................... 14 2.2.1 契约理论 .................................................................................................................................. 14 2.2.2 信息不对称理论 ...................................................................................................................... 16 2.2.3 委托代理理论 .......................................................................................................................... 16 3研究假设 .................................................................................................................................................. 18 3.1卖空机制对公司盈余管理的抑制作用 .......................................................................................... 18 3.2 股权结构对卖空机制与盈余管理关系的调节作用 ..................................................................... 19 3.2.1股权集中度对卖空机制与盈余管理关系的的调节作用 ....................................................... 19 3.2.2股权制衡度对卖空机制与盈余管理关系的的调节作用 ....................................................... 20 3.2.3股权性质对卖空机制与盈余管理关系的调节作用 ............................................................... 21 3.2.4机构投资者持股对卖空机制与盈余管理关系的的调节作用 ............................................... 22 西南科技大学硕士学位论 IV 4 研究设计 ................................................................................................................................................. 24 4.1 样本选取与数据来源 ..................................................................................................................... 24 4.2 变量定义及说明 ............................................................................................................................. 24 4.2.1 被解释变量 ................................................