Confidence and the Welfare of Less-Informed Investors

In response to recommendations by the AICPA Special Committee on Financial Reporting and the Association for Investment Management and Research, the FASB has recently invited comment regarding the question ?Given [efficient] markets, would any disservice be done to the interests of individual investors by allowing professional investors access to more extensive information?? (AICPA, 1996, p 22). Research in psychology (e.g., Griffin & Tversky, 1992) suggests that less-informed investors may suffer from overconfidence and trade too aggressively given their information. This paper reports two experiments designed to address these issues. In both experiments, security values are determined by the price/book ratios of actual firms, ?more-informed? investors observe three value-relevant financial ratios derived from Value-Line reports, and ?less-informed? investors observe only one of those signals. Experiment 1 provides evidence from a pencil-and-paper task that less-informed investors are overconfident relative to their more-informed counterparts, and that this relative overconfidence is reduced by alerting investors to the extent of their informational disadvantage. Trading behavior follows the same pattern as confidence assessments. Experiment 2 provides evidence from laboratory markets that, even after market prices have stabilized after many rounds of trading, less-informed investors systematically transfer wealth to more-informed investors as a result of biased prices and overly aggressive trading, but that alerting less-informed investors to the extent of their informational disadvantage eliminates these welfare losses. The results of both experiments thus suggest that providing information to only professional investors could harm the welfare of less-informed investors if less-informed investors are not aware of the extent of their informational disadvantage.