声誉、利益冲突与投资评级的乐观偏误

Reputation,Conflict of Interest and Optimistic Bias in Security Analysts' Investment Recommendations

证券公司的经纪和承销业务与证券分析师独立研究工作之间的利益冲突会使投资评级出现乐观偏误。文章使用2007年7月～2009年6月对沪深A股的投资评级数据并对此进行了检验。结果显示：在我国，经纪业务收入占营业总收入比重越高的证券公司其分析师越倾向于做出乐观评级，但证券公司与上市公司的承销关系对投资评级没有产生显著影响。进一步分析发现，对于机构投资者持股比例较高的股票，投资评级的乐观程度有所降低。由于机构投资者的评价在很大程度上会影响证券公司与证券分析师的声誉，这一结果从侧面反映了声誉因素在“中和”乐观偏误方面的积极作用。

Conflict of interest between brokerage and underwriting activities and security analysts＇ research may result in optimistic bi- as in investment recommendations. This statement is tested in this paper based on the investment recommendations from July, 2007 to June, 2009. It is found that ： in China, much more important brokerage activity is for security firms, more optimistic security analysts＇ recommendations are, while underwriting pressure seems to have no significant effect on investment recommendations. Furthermore, much more stocks institutional investors hold, less optimistic investment recommendations are. Because security firms and their ana- lysts＇ reputation are usually evaluated by institutional investors, career concerns have the important role in moderating the optimistic ]31as.