【作者】 张大勇；

【导师】 傅利平；

【作者基本信息】 天津大学 ， 技术经济及管理， 2011， 博士

【摘要】 随着股权分置改革的完成,我国证券市场制度环境发生了根本性的转变,作为典型新兴转轨的沪深A股市场加速进入全流通状态。由于全流通进程中大股东的效用函数发生了显著改变,这导致了大股东的隧道行为(tunneling)也相应地发生了与以往不同的改变,并且中小投资者利益保护问题也面临着更加严峻的挑战。如何有效地防范大股东对中小投资者利益侵害的隧道行为、保护中小投资者的合法权益以及提升上市公司价值成为全流通进程中以及全流通后我国资本市场亟待解决的重大现实问题。本论文以中小投资者利益保护为视角着重讨论了全流通进程中大股东在股份减持、内幕交易及整体上市的定向增发过程中的隧道行为,以及股权制衡与法律约束这两种内、外部公司治理机制对大股东隧道行为产生的有效抑制作用。主要结论与创新点如下:1.借鉴行为金融学的相关理论与研究成果,构建了我国沪深A股市场全流通进程中大股东的效用函数,通过对资产转移与股票价格之间关系的分析,得出了以下结论:第一,大股东存在提高未来股票转让价格的激励;第二,全流通进程中影响大股东行为的主要因素为大股东的持股比例、基于完全信息的股票价格期望值以及二级市场公司的股票价格;第三,与股权分置改革前相比,在股份减持、内幕交易与资产注入(整体上市的定向增发阶段)过程中大股东的隧道行为产生了新的特征。2.通过大股东股份减持的数量与被减持公司的托宾Q值、在所属行业中所处的估值水平以及在整个市场中所处的估值水平之间关系的实证检验,验证了在全流通进程中托宾Q理论对投资的引导作用。3.运用OLS与Logistic回归方法,实证分析了大股东通过操纵上市公司重大信息披露在股份减持过程中的隧道行为。得出了以下结论:第一,在减持前30个交易日被大股东减持的上市公司存在显著的正累计超额收益,但减持后30个交易日则存在显著的负累计超额收益;第二,被大股东减持的上市公司在减持前披露利好信息、减持后披露利空信息的概率高;第三,民营控股上市公司大股东操纵上市公司信息披露的概率较高;第四,被减持公司的托宾Q值越高,大股东信息操纵行为的概率越大;第五,被减持公司的净资产收益率(ROE)与总资产收益率(ROA)对大股东信息操纵行为的概率不存在显著影响。4.基于Logistic模型构建了全流通进程中大股东内幕交易这种隧道行为的识别体系与识别模型,并以2007年1月1日—2010年12月31日中国证监会公布的我国发生内幕交易行为的上市公司为样本,对全流通进程中上市公司大股东的内幕交易行为进行了实证研究,得出以下结论:第一,所构建的内幕交易识别模型能够较为准确的对市场实际交易中所存在的大股东内幕交易行为进行有效识别;第二,除了日均换手率之外,日均收益率、日均收益平方项以及日均收益率与日均换手率的乘积项均能够提高对内幕交易以及非内幕交易事件的正确识别率;第三,对选择大股东内幕交易行为识别的阀值问题,以本论文所给出的基准选取内幕交易识别的最优阀值(0.27)可以较大幅度地提升对市场中内幕交易行为的识别正确率,进而提高了样本的总体识别正确率;第四,根据市场环境的不同,应选择不同的阀值来对内幕交易行为进行有效识别。5.运用利益输送模型、事件分析法及会计分析法对我国2007年—2009年整体上市公司的定向增发样本进行了实证分析,得出以下结论:第一,约有69%的公司在整体上市过程中的定向增发阶段,存在大股东实施利益输送的隧道行为;第二,在定向增发阶段,累计超额收益率在窗口期内存在显著的正公告效应,在窗口期时间拉长后累计超额收益率存在显著的负公告效应;大股东的隧道行为使上市公司在定向增发阶段存在明显的窗口期超额收益和上市公司公告发布后低于市场平均收益的显著特征;第三,集团公司整体上市后,大股东隧道行为的存在,导致了短时期内关联交易额没有显著下降的趋势,盈利能力也没有显著增强。6.以股权制衡与法律约束这两种内部与外部治理机制为视角分析了全流通进程中抑制大股东对中小投资者和上市公司利益侵害的隧道行为。通过构建基于股东行为的多主体互动博弈均衡模型以及对黄光裕内幕交易案的案例分析,得出了股权制衡与法律约束这两种公司治理机制能够有效地抑制全流通进程中大股东的隧道行为,进而最大限度地保护中小投资者与上市公司利益的结论。作为典型的新兴转轨市场,我国沪深A股市场股权分置改革已经顺利完成,市场加速处于全流通的进程中。但是我国上市公司一股独大的集中型股权结构、所有者缺位以及内部人(控股股东和公司高管)控制的特征在短时期内仍然无法改变。保护中小投资者利益的相关法律法规和司法体系还有待继续健全与完善,大股东侵害中小投资者和上市公司利益的隧道行为愈加隐蔽以及愈加难以识别,资本市场资源配置的功能也有待加强。如何有效地防范大股东对中小投资者利益的侵害、保护中小投资者的合法权益以及提升上市公司的价值成为全流通进程中以及全流通后我国证券市场亟待解决的首要现实问题。这些问题的产生既有公司内部治理机制缺陷的原因,也有公司外部治理机制的不健全的原因,但均与大股东的隧道行为有着紧密的直接联系。因此,基于中小投资者利益保护视角对全流通进程中我国沪深A股市场大股东隧道行为进行研究,不仅对促进全流通后我国资本市场的稳定健康的可持续发展、提高资源配置效率、规范公司治理结构以及降低资本成本,而且对政府实施有效监管有着比较重要的理论与现实指导意义。更多还原

【Abstract】 With the implementation of state share sale reform, Chinese capital market system environment underwent fundamental changes. Shanghai and Shenzhen A-stock markets are making their way into fully circulating process rapidly. Major shareholders’tunneling has changed dramatically while medium and small sized investors are confronted with an increasingly serious problem of protecting their individual interests. Under such circumstances, some significant practical problems arise and demand urgent solutions in our national capital market during and after full circulation, including how to hinder major shareholders from infringing upon medium and small sized investors, how to protect medium and small sized investors’interests and how to promote listed companies’value, and so on. From the perspective of protecting medium and small sized investors’interests, this dissertation elaborates on major shareholders’tunneling in the fully circulating process with regard to reducing shares, insider dealing and whole group listings. It also analyzes how these two external governance mechanisms, that is, equity interest check-and-balance and legal binding, manage to inhibit major shareholders’tunneling. The main achievement and innovation of this dissertation are as follows:First of all, with reference to the relevant theory of behavioral finance, we devise utility function of major shareholders in the process of full circulation. According to our analysis about the relationship between asset transfer and stocks price, we come to the following conclusions. First, major shareholders are inclined to increase the future share transfer price. Next, the main factors that influence major shareholders’behavior include major shareholder’s shareholding ratio, share price expectation and secondary market price. Thirdly, major shareholders’tunneling is characterized by stake reduction with a high price, insider trading and asset injection, etc.Then, empirical research is carried out to examine the relationship between the estimated value of listed companies that cut stakes, along with its estimate value in the specific industry and the whole market, and the amount of reduced stake of major stockholders. Meanwhile, our research also demonstrates that Tobin’s Q theory plays a leading role in the fully circulating process.In the third place, based on OLS and Logistic Regression, we conduct the empirical studies concerning major shareholders’tunneling by controlling important information disclosure in the process of stake reduction and draw the following conclusion. Firstly, for the past 30 market days prior to stake cut, the listed company gains remarkable positive accumulated benefits while it obtains striking negative accumulated benefits for the next 30 market days. Secondly, the listed company tends to reveal good news before its stake reduction, but reveal discouraging news after taking action. Thirdly, major shareholders of private listed companies are more likely to violate medium and small-sized investors’interests by controlling the company’s information disclosure. In contrast, state-owned holding companies do not exhibit this feature. Finally, if Tobin Q-value of the listed company that reduces stake is high, major shareholders are supposed to be more likely to control the listed company to reveal some important information.Fourthly, based upon Logistic Model, we work out the discrimination system and identification model of insider dealing. The following points are concluded according to our empirical studies. On the one hand, generally, the basic insider functions as the principal body of insider trading. Inside information is mainly focused on merger and acquisition, as well as profit sharing. On the other hand, except daily turnover ratio, such variables as daily earnings rate, daily earnings quadratic term and product term of daily turnover ratio and daily earnings rate all can help to distinguish insider trading and non-insider trading effectively.Next, empirical analysis is made about whole group listings and company performance by employing Scene Analysis and Accounting Analysis. The following are some of our findings. First of all, listed companies announce that whole group listings can bring positive wealth effect and involve insider trading. Secondly, the company’s short-term earning power can be strengthened after whole group listings. Thirdly, the company’s connected transaction decrease dramatically. Fourthly, major shareholders tend to have more convert tunneling during the course of whole group listings.Lastly, we also examine why the company’s internal governance mechanism fails to curb major shareholders’tunneling and protect medium and small sized investors’interests. Moreover, from the perspective of shareholders, we construct a game equilibrium model that involves multi-agent interaction. A case study of Huang Guangyu’s insider trading is carried out thoroughly. As a consequence, we can safely draw the conclusion that the two external governance mechanisms, that is, equity interest check-and-balance and legal binding, manage to inhibit major shareholders’tunneling and protect medium and small sized investors’interests effectively .As a typical emerging market, the share reform has been successfully completed in the Shanghai and Shenzhen A-share market . The market is in full circulation process acceleratly. However, the features of listed companies still does not change such as, the concentrated ownership structure, the owner absence and insiders control in the short term. The laws of protection of the interests of small investors ,the relevant regulations and the judicial system yet have to continue to improve. The hidden tunneling of major shareholders of listed companies aggrieve the interests of small investors and even more difficult to identify.The function of resource allocation of capital market also needs to be strengthened step by step. That how to effectively prevent a large shareholder aggrieve the interests of small investors to protect the legitimate rights and interests of small and medium investors and how to effectively enhance the value of listed companies is becoming important in the circulation process of the stock market. Both of these problems have defects in the internal governance reasons, but also outside governance reasons. All the reasons have close direct contact for the major shareholders behavior.Therefore, based on protecting the interests of small investors we study the tunneling of large shareholders of the process of circulation of the Shanghai and Shenzhen A-share market,not only to promote the China’s capital market , to improve resource allocation efficiency, to standardize corporate governance structure and to lower capital costs, but also to enhance effective supervision of the government. It has more important theoretical and practical significance.更多还原