存在控股股东下的卖空治理效应及其检验

中国“一股独大”的特殊股权结构对卖空治理效应的影响不可忽视。以中国融资融券制度实施作为准自然实验，基于企业的投资行为，采用双重差分方法检验中国控股股东的存在对卖空治理效应的影响。进一步地，考察中国上市公司的内部股权治理机制（如股权制衡、机构投资者及个人投资者持股）对存在控股股东情形下的卖空治理效应的影响。经检验发现，与不存在控股股东的企业相比，存在控股股东的企业在引入卖空机制后，其投资支出（或过度投资）的下降程度更大，符合所提出的“卖空压力假说”的预期；不仅如此，控股股东的持股比例越高，卖空的治理效应越大。在进行了一系列内生性和稳健性检验后，结论依然成立。进一步的研究发现，在股权制衡较弱的企业、机构投资者持股较高或主要由稳定型机构投资者持股的企业以及个人投资者持股较低的企业中，卖空的上述治理效应得到强化。研究结论表明，中国企业以大股东控制为典型特征的股权结构有效促进了卖空治理效应的发挥。

Governance Effects of Short Selling from the Perspective of Controlling Shareholders

The impact of China’s dominant special ownership structure on the governance effect of short selling cannot be ignored. Taking the implementation of margin trading and short selling system as a quasi-natural experiment, and based on corporate investment behavior, in this paper, Difference-in-Difference method was used to examine the impact of controlling shareholders on governance effect of short selling in China. Furthermore, the impact of the internal ownership governance mechanism (such as balanced ownership structure, institutional investors and individual investors) on the governance effect of short selling under the existence of controlling shareholders was also investigated. The results show that, compared with firms without controlling shareholders, firms with controlling shareholders had a greater decrease in investment expenditure or overinvestment after the introduction of short selling mechanism, which is consistent with the expectations of ‘short-selling pressure hypothesis’ proposed by this paper. Moreover, the higher control degree of the controlling shareholder, the greater governance effect of short selling. After a series of endogeneity and robustness tests, the conclusions still hold. Further research shows that, the above governance effect of short selling was strengthened in firms with weaker balanced ownership structure, higher institutional investors shareholdings or mainly owned by stable institutional investors and lower individual investors shareholdings. The conclusion shows that the special ownership structure of controlling shareholders in China effectively promotes the governance effect of short selling.