David A. Hirshleifer

A Theory of Fads, Fashion, Custom, and Cultural Change as Informational Cascades

An informational cascade occurs when it is optimal for an individual, having observed the actions of those ahead of him, to follow the behavior of the preceding individual without regard to his own information. We argue that localized conformity of behavior and the fragility of mass behaviors can be explained by informational cascades.

Investor Psychology and Security Market Under- and Overreactions

We propose a theory of securities market under- and overreactions based on two well-known psychological biases: investor overconfidence about the precision of private information; and biased self-attribution, which causes asymmetric shifts in investors’ confidence as a function of their investment outcomes. We show that overconfidence implies negative long-lag autocorrelations, excess volatility, and, when managerial actions are correlated with stock mispricing, public-event-based return predictability. Biased self-attribution adds positive short-lag autocorrelations ~“momentum”!, short-run earnings “drift,” but negative correlation between future returns and long-term past stock market and accounting performance. The theory also offers several untested implications and implications for corporate financial policy. IN RECENT YEARS A BODY OF evidence on security returns has presented a sharp challenge to the traditional view that securities are rationally priced to ref lect all publicly available information. Some of the more pervasive anomalies can be classified as follows ~Appendix A cites the relevant literature!: 1. Event-based return predictability ~public-event-date average stock returns of the same sign as average subsequent long-run abnormal performance! 2. Short-term momentum ~positive short-term autocorrelation of stock returns, for individual stocks and the market as a whole!

Good Day Sunshine: Stock Returns and the Weather

Psychological evidence and casual intuition predict that sunny weather is associated with upbeat mood. This paper examines the relationship between morning sunshine in the city of a countrys leading stock exchange and daily market index returns across 26 countries from 1982 to 1997. Sunshine is strongly significantly correlated with stock returns. After controlling for sunshine, rain and snow are unrelated to returns. Substantial use of weather-based strategies was optimal for a trader with very low transactions costs. However, because these strategies involve frequent trades, fairly modest costs eliminate the gains. These findings are difficult to reconcile with fully rational price setting.

Herd Behaviour and Cascading in Capital Markets: A Review and Synthesis

We review theory and evidence relating to herd behaviour, payoff and reputational interactions, social learning, and informational cascades in capital markets. We offer a simple taxonomy of effects, and evaluate how alternative theories may help explain evidence on the behaviour of investors, firms, and analysts. We consider both incentives for parties to engage in herding or cascading, and the incentives for parties to protect against or take advantage of herding or cascading by others.

Investor Psychology in Capital Markets: Evidence and Policy Implications

We review extensive evidence about how psychological biases affect investor behavior and prices. Systematic mispricing probably causes substantial resource misallocation. We argue that limited attention and overconfidence cause investor credulity about the strategic incentives of informed market participants. However, individuals as political participants remain subject to the biases and self-interest they exhibit in private settings. Indeed, correcting contemporaneous market pricing errors is probably not governments relative advantage. Government and private planners should establish rules ex ante to improve choices and efficiency, including disclosure, reporting, advertising, and default-option- setting policies. Especially, government should avoid actions that exacerbate investor biases.

Share Tendering Strategies and the Success of Hostile Takeover Bids

This paper presents a model of tender offers in which the bid perfectly reveals the bidders private information about the size of the value improvement that can be generated by a takeover. We argue that bidders with greater improvements will offer higher premia to ensure that sufficient shares are tendered to obtain control. The model relates announcement date returns and takeover success or failure to the amount bid, the initial shareholdings of the bidder, the number of shares the bidder attempts to purchase, the dilution of minority shareholders, and managerial opposition. We show that managerial defensive measures will sometimes increase the probability of the offers success, either by raising the incentive to bid high or by decreasing the asymmetry of information about the improvement.

Do Tender Offers Create Value? New Methods and Evidence

We develop the Probability Scaling Method, which rescales short-window announcement period returns; and the Intervention Method, which uses returns associated with intervening events, to estimate value improvements from tender offers. These methods address biases in conventional techniques, which measure only a fraction of the total tender offer gain; and which include revelation about bidder stand-alone value. Perceived value improvements are much larger than traditional methods indicate, so that we cannot reject the hypothesis that bidders on average pay fair prices for targets. Furthermore, our new methods affect inferences about economic forces in the takeover market. We identify several effects (higher combined bidder-target stock returns for hostile offers, lower for equity offers, and lower for diversifying offers) that reflect differences in revelation about stand-alone value, not gains from combination.

Risk, managerial effort, and project choice

In our model risk-neutral shareholders need to motivate a manager to select among projects with different risks, and to work hard in implementing the chosen project. Curvature of the managers compensation contract as a function of profit affects his attitude toward project risk. The optimal curvature depends on the trade-off between controlling project risk and motivating effort. The analysis predicts greater option-based compensation when there are desirable risky growth opportunities (proxied by Tobins q or R&D expenditures) and less option compensation when there are effective monitoring institutions (such as outside directors and bank lenders).

Managerial Reputation and Corporate Investment Decisions

This review examines the incentives of managers to use investment choices as a tool for building their personal reputations or the reputation of their firms. These incentives come in three main forms: visibility bias, which encourages a manager to try to make short-term indicators of success look better; resolution reference which encourages a manager to try to advance the arrival of good news and delay bad news; and mimicry and avoidence, which encourages a manager to take the actions that the best managers are seen to do, and to avoid the actions the worst managers are seen to do.

Price Discrimination Through Offers to Match Price

In this paper, a firm discriminates between two classes of customer who have a different cost of information by coupling a list price with an offer to match the pr ice of any other shop. If the list price elsewhere is lower, the firm will be successful in discrimination. The list price of each firm is increasing in the number of sellers and the total sales are decreasi ng in the number of sellers. Furthermore, if sellers coordinate, they discriminate more efficaciously and increase their profits by increa sing their total sales. Copyright 1987 by the University of Chicago.