An Assessment of Individual Investor Reaction to Certain Qualified Audit Opinions.
研究1973-1977年66对匹配公司中，个体投资者对审计师关于不确定性事项的保留意见的反应，发现投资者在保留意见出现和消除时调整投资组合，且反应持续时间长于价格研究中的结果。
Abstract This research investigated investor reactions to auditors' decisions concerning unusual uncertainties. Individual, rather than market, reactions were investigated in order to capture effects that can often be masked by price-based aggregate market methods. This was accomplished by an examination of trading volume over 30 trading days surrounding the announcement of the nature of audit opinions for 66 matched pairs of firms during the period 1973-1977. Examinations included comparisons between experimental and control groups of firms for each day, and also for an information release period, compared with control periods when no similar information was issued. Statistically significant portfolio adjustments were discovered when uncertainty qualifications first appeared, and again when they were removed, and the reactions lasted longer than those normally reported in price-based research into the information content of accounting-related information. The results provide evidence that auditors' decisions and reports concerning uncertainties affect individual investors' portfolio holding decisions.