公司治理与内幕交易监管效率研究

内幕交易通常被各国证券监管部门认定为一种非法的证券交易行为,许多证券市场都引入了内幕交易监管法律制度。本文的研究目的是从公司治理角度来分析哪些因素影响着国内内幕交易监管效率,分析国内监管能否有效遏制内幕交易行为,并从公司价值角度探讨了特定公司治理背景下内幕交易行为能否受到市场自然的惩戒。由此,本文提出了改善监管效率的相关建议。     

内幕交易的经济学分析

该文探讨了中国市场的内幕交易理论,在此基础上提出了4个可检验的假说:(1)内幕交易在中国必定存在;(2)内幕交易在中国比成熟市场更加严重;(3)重大事件中内幕交易的严重程度和管理层付出呈正比关系;(4)内幕交易多围绕利好消息.利用1078个并购重组事件和其他上市公司重大事件为样本,该文运用事件研究法,证实了上述假说.在此基础上,提出了中国内幕交易立法和监管的思路.     

内幕交易监管：国际经验与中国启示

内幕交易违反了金融市场的公平原则,降低了资本市场的效率,但是由于其金融交易的特殊性,使得它在监管上存在一定的难度。本文在梳理内幕交易行为的理论基础、对内幕交易监管的争议进行讨论的基础上,从内幕人认定、内幕信息认定、内幕交易行为认定、防范措施以及法律制裁与救济等五个不同的维度对美国、日本、欧盟和我国的内幕交易法律制度进行比较分析,从而总结我国法律在内幕交易规制方面的不足,并相应地提出改进的建议。     

内幕交易的经济学分析

本文探讨了中国市场的内幕交易理论,在此基础上提出了4个可检验的假说:(1)内幕交易在中国必定存在;(2)内幕交易在中国比成熟市场更加严重;(3)重大事件中内幕交易的严重程度和管理层付出呈正比关系;(4)内幕交易多围绕利好消息。利用1078个并购重组事件和其他上市公司重大事件为样本,本文运用事件研究法,证实了上述假说。在此基础上,提出了中国内幕交易立法和监管的思路。     

内幕交易:理论、模型及实证研究

对内幕交易的研究始于证券监管的历史,近年来,随着理论的发展和数据的充足以及越来越多的国家加强对内幕交易的监管,内幕交易已成为金融市场理论中的热点研究领域。本文在综合国外研究成果的基础上,着重从理论、模型及实证三个方面对其发展进行了深入论介,最后对其未来的发展方向和研究重点提出了展望。     

A game theory model of regulatory response to insider trading

We develop a model which can help in explaining the evolving regulatory regime around insider trading. We form a simple sequential game-theoretical model of insider trading transactions and, utilizing Monte Carlo simulation to determine equilibrium, we show that costly investigations and low penalties incentivize traders to engage in illegal transactions. While the model helps to explain stiffer action by regulatory bodies, the question remains as to whether the elevated penalty levels are sufficient to prevent further insider trading.     

内幕交易监管、投资者交易策略与市场利益分配

当证券市场实施内幕交易监管后,投资者的交易策略可能会发生改变,市场利益的分配也会发生相应的改变。文章在一个实施内幕交易监管的框架下,对内部人的利益分配进行了研究,发现内部人的利益不仅与内幕交易监管力度和执行能力有关,还与市场流动性、交易者类型、信息准确度和市场波动性等因素密切相关。同时,由于监管有效性幻觉和内部人分层现象的存在,内部人利益在一定时期内还可能出现反常变动。     

What Is Common Among Return Anomalies? Evidence from Insider Trading

For a broad set of anomalies, we establish a common pattern of underreaction to information contained in preceding insider trading activity. Our main analysis focuses on the anomalies' short legs, which generate persistent negative abnormal returns. For stocks in the short legs, future returns are systematically related to the information signal contained in preceding insider trading activity, indicating underreaction. For insider trading information, we consider the possibility of net buying, net selling, and no trading (or silence). The underreaction effect is economically significant, with the most negative signal accounting for an average of 71% of short-leg returns. This underreaction effect survives numerous robustness checks and remains important after accounting for investor sentiment, information environment, and limits to arbitrage.     

Real and financial effects of insider trading with correlated signals

Summary. In this paper we study the real and financial effects of insider trading in a Static, Kyle-type model. In our model the insider is also the manager of the firm. Hence the insider chooses both the amount of the real output to be produced and the amount of the stock of the firm to trade. The aim of the paper is to study the relationship between financial decisions and real decisions. In particular, we examine how insider trading on the stock market affects the real output and price and how the real decision making affects the financial variables, such as the extent of insider trading, stock prices, and the stock pricing rule of the market maker. In the model, the market maker observes two correlated signals: the total order flow and the market price of the real good. We study the informativeness of the stock price and the effects on insider's profits. We also construct a compensation scheme that aligns the interests of the insider and the firm. Finally, we generalize the pricing rule set up by a competitive market maker and analyze the comparative statics of the model. Received: October 3, 1999: revised version: December 1, 1999     

The effects of insider trading on insiders effort in good and bad times

We analyze the effects of insider trading on insiders' effort decisions and on the value of firms. We consider a situation in which the final output of a firm and the productivity of managerial effort will depend on whether the firm is in a good or a bad state. When the state is not verifiable, the managerial contract cannot be made explicitly contingent on it: consequently, a contract that does not allow for insider trading would lead to the insiders' facing the same incentive scheme in good and bad times. Under a contract that allows for insider trading, however, insiders will buy shares on receiving (ahead of the market) good news and will sell shares on receiving bad news; consequently, they will end up facing different incentive scheme in good and bad times. Whether this effect is desirable depends on how the marginal productivity of managerial effort in good times compares with that in bad times. In particular, we show that allowing insider trading may improve managers' effort decisions and consequently may increase corporate value and benefit shareholders.     

Information disclosure with leakages

We present a trading game with one insider, many outsiders, liquidity traders and a competitive market maker trading an asset with two value components, a private and a shared one, in a market operating as in Kyle (1985). The insider knows both value components and outsiders only know the shared component. The market maker receives a private signal in the form of a noisy transformation of the shared component, which we refer to as leakages. Before trade begins, the insider can disclose the value of the shared component to the entire market, thus removing the outsiders from the game. When the market maker's signal is sufficiently precise, the insider's benefit from knowing the shared component does not exceed the cost of concurrently trading with the outsiders, thus motivating the insider to reveal the shared component to the entire market. This result provides an explanation as to why some firm managers may naturally prefer to publicly disclose information rather than leaving it in the hands of select investors.     

管理者交易的市场择时能力对市场有效性的影响

管理者卖出和买入公告对股票市场具有一定的影响,以管理者卖出交易和买入交易为公告样本进行实证分析,检验公告当日及给定事件期超额收益的显著性.结果显示:卖出公告样本反对半强式有效假说,管理人能够“卖高”,获得超额收益；而买入公告样本支持半强式有效假说,管理者不能够“买低”,在公告日和事件期都不能获得超额收益.     

融券制度与内部人寻租——来自准自然实验的经验证据

内部人寻租一直以来是理论与实务界关心的重点,如何有效抑制内部人寻租行为是资本市场的重大课题。本文以内部人交易度量内部人寻租,分析了融券制度对内部人寻租的影响。研究发现:(1)融券制度对内部人寻租有显著抑制作用,并且融券规模越大,内部人寻租越少。(2)相比于国有企业,非国有企业当中融券制度对内部人寻租的抑制作用更加明显。本文还将内部人交易分方向进行回归,结果显示融券制度对内部人寻租的抑制作用主要体现在卖出方向上。本文进一步分析了融券制度影响内部人寻租的路径,发现“竞争效应”和“信息效应”是融券制度影响内部人寻租的两条重要路径。本文考虑了竞争性解释——分析师关注的作用,发现分析师关注并不能影响本文结论的正确性;本文还利用反面事实推断、倾向得分匹配、反向因果检验等方法,确保实证结论的稳健性。本文的研究结果,丰富了内部人寻租的特征及影响因素研究,有利于市场监管部门加强对内部人寻租行为的控制;扩充了有关融券制度的文献,为卖空制度的推行及完善提供理论依据。     

证券市场内幕交易的行为动机研究

2007年中国资本市场进入了全流通时代,全流通下内幕交易可能会比股权分置时更加严重,如何有效防范大股东和机构投资者利用信息优势、资金优势、控制权优势进行内幕交易,是全流通下内幕交易监管防范面临的主要挑战。本文从内幕交易的行为动机及其影响因素展开研究,借鉴Becker(1968)"犯罪经济学"的研究框架及行为金融学的相关理论,选取了相应影响因素的度量指标,架构了内幕交易行为动机模型。然后基于问卷调查的模拟数据,运用结构方程模型对影响内幕交易行为动机模型中各个变量之间的逻辑关系和内在影响机制进行了实证研究,得出富有价值的研究结论,并据此给出相应的政策建议。     

上市公司内部人交易披露延迟及其经济后果研究——来自上海股票市场的经验证据

文章研究了我国上市公司内部人交易信息披露延迟的现状及其影响因素,以及披露延迟对内部人交易市场反应的影响。研究发现,整体而言,内部人交易存在披露延迟;交易披露延迟时间的长短与交易方向、交易是否处于信息敏感期、公司流通股比例、交易规模有关;在信息披露延迟严重的买入样本组,内部人职务对披露延迟产生了影响。市场给予内部人卖出股票负面评价而对买入股票的反应不显著;内部人交易的市场反应不受信息披露延迟影响。     

Efficient Selection and Insider Contracting Groups: a Comment on the Yarbrough & Yarbrough Paper

Beth & Robert Yarbrough's paper reviews and augments an extensive literature analyzing how insider trading groups support the process of exchange. They argue that these groups efficiently adapt to changes in the transacting environment. Yarbrough & Yarbrough's argument is compelling for groups operating in a free and open civil society but not when competition among groups is impaired by barriers to entry and externalities. This article considers whether insider trading groups are able to reach a steady-state equilibrium and presents a number of historical and contemporary examples in which insider trading groups plant the seeds of their own destruction.     

Insider trading returns and dividend signals

The literature shows that insider trading activities and dividends contain information content and serve as signals to firm value. If insider return is a proxy for information asymmetry, we should expect a positive relation between dividends and insider returns. Using a sample of unambiguous (good and bad) news concerning earnings and dividend announcements from Hong Kong firms, we show that information asymmetry is stronger for bad news firms with insider sales than good news firms with insider purchases. In addition, we improve the methodology of Khang and King [Khang, K., & King, T. H. D. (2006). Does dividend policy relate to cross-sectional variation in information asymmetry? Evidence from returns to insider trades. Financial Management, 35, 71–94] and provide evidence that dividend is a credible signal for measuring information asymmetry.     

内部人交易与股票市场回报——来自中国市场的证据

本文系统地分析了自2007年6月1日以来,我国上市公司内部人的公开市场交易行为。本文的结论表明,在实施了内部人交易监管法规以来,我国上市公司的内部人依然能够利用私有信息在二级市场上赚取超额收益。当内部人购买或出售公司股票时,股票市场都会出现异常反应。而这些超额收益的大小直接受到公司的股权集中度、企业是否为国有等因素的影响。公司治理结构越差,则内部人赚取的超额收益越多。依据上述结论,笔者提出了相应的政策建议。     

Regulating Insider Trading In Betting Markets

Although trading in securities in conventional financial markets on the basis of inside information is restricted by law, the rules against such trading in betting markets are rather more ambiguous. It is argued in this paper that, since insider trading in betting markets imposes a cost on the great majority of bettors, tighter strictures against such trading would benefit all but the insiders. This case is supported by the use of empirical evidence which shows that betting markets which are characterized by tighter controls against insider activity are also characterized by a significantly lower incidence of such activity.     

Stackelberg financial-leader in insider trading model

In this paper, we extend the Jain-Mirman [Jain, N., & Mirman, L. (2000). Real and financial effects of insider trading with correlated signals. Economic Theory, 16, 333–353, Jain, N., & Mirman, L. (2002). Effects of insider trading under different market structures. The Quarterly Review of Economics and Finance, 42, 19–39] and the Daher-Mirman [Daher, W., & Mirman, L. (2006). Cournot duopoly and insider trading with two insiders. The Quarterly Review of Economics and Finance, 46, 530–551, Daher, W., & Mirman, L. (2007). Market structure and insider trading. International Review of Economics and Finance, 16, 306–331] papers on competition, and postulate that the competition among the insiders in the financial market be Stackelberg. However, an owner high in the organizational hierarchy, who designs manager compensation mechanisms and chooses a manager to serve his purpose, should have information on the manager's reaction and act as a Stackelberg leader in the financial sector. We show that owner's profit can definitely enlarged while the manager's profits may decrease or increase depending on the variances in the two sectors, which are the exogenous parameters.