證券分析師股票推薦樂觀性差異與利益衝突規範影響性之研究

Abstract

This study examines bias in recommendations following the enactment of the research analyst conflict of interest rules introduced around 2002. Most academic and regulatory efforts have been directed towards the problems derived from the conflicts of interest and biases in underwriter analyst recommendations while unaffiliated recommendations generally pass as being relatively objective and thus exempt from examinations. We label analyst recommendations as being seemingly unaffiliated when contributors are not underwriters but an acquirer or target firm of underwriters. We find that after the introduction of the rules, bias in affiliated recommendations diminishes, whereas seemingly unaffiliated recommendations reveal no signs of difference in their level of optimism. Moreover, both affiliated and seemingly unaffiliated analysts disproportionately issue unfavorable recommendations for unaffiliated firms immediately before the effective date of the rules. Our empirical evidence indicates that seemingly unaffiliated recommendations are subject to conflicts of interest. During the process of mergers and acquisitions, analysts from target firms appear to issue more optimistic recommendations than unaffiliated analysts do on their acquirer firms’ clients. After the announcement date, recommendations issued by target analysts are more optimistic than those by unaffiliated analysts despite the fact that former recommendations are relatively pessimistic before the announcement date.