中国评级市场被“劣币驱逐良币”机制主导了吗

声誉机制能够产生“优胜劣汰”的压力，是对评级机构行为的重要约束。中国舍本逐末的评级制度安排和不成熟的市场环境不仅阻碍了声誉机制的形成，还为评级机构出具过高评级提供了空间。根据该情况构建的评级合谋市场均衡模型，证明了我国评级市场竞争增加会导致评级质量的下降。利用鹏元资信评估有限公司进入城投企业债评级市场作为自然实验的进一步研究对理论进行了验证。分析表明，“劣币驱逐良币”的恶性竞争机制在我国评级市场占据主导地位。为此，我国在长期内应当对评级行业的制度安排进行重新设计，建立以声誉机制为主导的市场环境；短期内则需要加强监管，同时控制评级市场的竞争程度。

Has ‘Survival of the Fittest’ Mechanism Dominated the Rating Market in China

The reputation mechanism which can generate the pressure of ‘Survival of the Fittest’, is an important restriction to behavior of credit rating agencies. It is China's credit rating system which sacrifices the substance for the shadow and immature rating market, which not only hindered the formation of reputation mechanism but also provided space for CRAs to offer higher ratings. Based on above, this paper built up a model of equilibrium in rating conspiring market and proved that the market competition in credit rating market of China would lower the quality of credit ratings. And by taking Peng Yuan's entry into the credit rating market of quasi-municipal bond as a natural experiment, we found empirical evidences. Analysis shows that the vicious competition mechanism of ‘bad money drives out good money’ has dominated the credit rating industry. For suggestions, the Chinese government should reshape the restriction mechanisms for CRAs and built up a rating market dominated with reputation mechanism in the long run. As in short run, the government needs to enhance supervision and make a control on the market competition.