Abstract: Credit rating inflation refers to the phenomenon of inflated credit ratings given to companies by rating agencies. The existence of credit rating inflation not only intensifies the degree of information asymmetry in the market, affecting the normal pricing of the bond market and the effective allocation of market resources, but also distorts the credit risk assessment, resulting in the accumulation of default risk in the whole market. Therefore, it is of great significance to scientifically analyze the factors of credit rating inflation and study how the factors affect credit rating inflation. This paper analyzes the theoretical impact and mechanism of short selling on credit rating inflation, and adopts the data of listed firms from 2011 to 2021 for empirical test. The results of the study are as follows: (1)Short selling can significantly inhibit credit rating inflation, and this effect still holds after endogeneity test and other robustness tests; (2) This inhibitory effect is realized through real earnings management and information disclosure quality channels; (3)This effect is more obvious in firms with poor internal control quality, large analyst optimism bias, low institutional investor shareholding ratio and issuer paid rating agencies. Based on the above conclusions, this paper puts forward the following policy suggestions: First, considering the inhibitory effect of short selling mechanism on credit rating inflation, the regulatory authorities should reduce the restrictions on securities financing and give full play to the “deterrence before the event” and “punishment after the event” of short selling mechanism, thus improving the quality of credit rating and alleviate credit rating inflation. Second, considering that the short selling mechanism is conducive to the mining and transmission of negative information, rating agencies should fully consider whether the companies can be short-sold as well as the intensity of short selling in the process of credit rating so as to reduce the degree of credit rating inflation. Third, considering the heterogeneous role and intermediary mechanism of short selling mechanism, the regulatory authorities should timely and reasonably include companies with poor internal control level and low earnings quality into the short selling list in order to effectively restrain their opportunistic motives and alleviate the problem of credit rating inflation. The main contributions and innovations of this paper are as follows: (1) This paper analyzes the inhibitory effect of short selling mechanism on credit rating inflation and its action path, which provides a new perspective for the governance of credit rating inflation. The existing researches on the influencing factors of rating inflation mainly focus on the issuer payment mode, the competition of rating market and the distortion of rating regulation. However, the governance effect of short selling mechanism on rating inflation has not been explored. This paper studies the inhibitoryeffect of short selling on credit rating inflation and its mechanism from both theoretical and empirical aspects, providing theoretical support and empirical evidence for the management of credit rating inflation. (2) Starting from the basic institutional arrangement of the bond market—credit rating, this paper enriches the research on the economic consequences of short selling mechanism. Existing studies on the consequences of short selling mechanism mainly focus on pricing efficiency, volatility and liquidity, earnings management, financing and innovation, but do not study the inhibitory effect of short selling mechanism on credit rating inflation and its structural effect. This paper studies the structural effect of short selling mechanism on credit rating inflation, and provides new ideas to better exert the governance effect of short selling mechanism.

Key words: Short Selling Mechanism, Credit Rating Inflation, Real Earnings Management, Quality of Information Disclosure, Governance Effects

摘要： 本文分析了卖空机制对信用评级膨胀的理论影响和作用机制,并采用2011—2021年上市公司数据进行实证检验,结果发现:(1)卖空机制可以显著抑制信用评级膨胀,并且这种抑制效应在内生性检验和其他稳健性检验后依然成立;(2)卖空机制对信用评级膨胀的抑制效应是通过真实盈余管理和信息披露质量渠道实现的;(3)卖空机制对信用评级膨胀的抑制效应在内部控制质量较低、分析师乐观偏差较大、机构投资者持股比例较低与发行者付费模式的公司中更加明显。

关键词: 卖空机制, 信用评级膨胀, 真实盈余管理, 信息披露质量, 治理作用