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!

/pdf/investor-psychology-and-security-market-under-and-108faczcym.pdf

Investor Psychology and Security Market Under- and Overreactions

A review is presented of the book “Heuristics and Biases: The Psychology of Intuitive Judgment,” edited by Thomas Gilovich, Dale Griffin, and Daniel Kahneman.

Heuristics and Biases: The Psychology of Intuitive Judgment

The effect of disclosure level on the cost of equity capital is a matter of considerable interest and importance to the financial reporting community However, the association between disclosure level and cost of equity capital is not well established and has been difficult to quantify In this paper I examine the association between disclosure level and the cost of equity capital by regressing firm-specific estimates of cost of equity capital on market beta, firm size and a self-constructed measure of disclosure level My measure of disclosure level is based on the amount of voluntary disclosure provided in the 1990 annual reports of a sample of 122 manufacturing firms For firms that attract a low analyst following, the results indicate that greater disclosure is associated with a lower cost of equity capital The magnitude of the effect is such that a one-unit difference in the disclosure measure is associated with a difference of approximately twenty-eight basis points in the cost of equity capital, after controlling for market beta and firm size For firms with a high analyst following, however, I find no evidence of an association between my measure of disclosure level and cost of equity capital perhaps because the disclosure measure is limited to the annual report and accordingly may not provide a powerful proxy for overall disclosure level when analysts play a significant role in the communication process

https://www.jstor.org/stable/pdf/248475.pdf

Disclosure level and the cost of equity capital

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. 
Prepublication version available at https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2017

Presentation Slides for 'Investor Psychology and Security Market Under and Overreactions'

Much research in the last two decades has demon- strated that human responses deviate from the performance deemed normative according to various models of decision mak- ing and rational judgment (e.g., the basic axioms of utility theory). This gap between the normative and the descriptive can be inter- preted as indicating systematic irrationalities in human cognition. However, four alternative interpretations preserve the assumption that human behavior and cognition is largely rational. These posit that the gap is due to (1) performance errors, (2) computational limitations, (3) the wrong norm being applied by the experi- menter, and (4) a different construal of the task by the subject. In the debates about the viability of these alternative explanations, attention has been focused too narrowly on the modal response. In a series of experiments involving most of the classic tasks in the heuristics and biases literature, we have examined the implica- tions of individual differences in performance for each of the four explanations of the normative/descriptive gap. Performance er- rors are a minor factor in the gap; computational limitations un- derlie non-normative responding on several tasks, particularly those that involve some type of cognitive decontextualization. Un- expected patterns of covariance can suggest when the wrong norm is being applied to a task or when an alternative construal of the task should be considered appropriate.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0140525X00003435

Individual differences in reasoning: Implications for the rationality debate?

This study examines whether security analysts underreact or overreact to prior earnings information, and whether any such behavior could explain previously documented anomalous stock price movements. We present evidence that analysts' forecasts underreact to recent earnings. This feature of the forecasts is consistent with certain properties of the naive seasonal random walk forecast that Bernard and Thomas (1990) hypothesize underlie the well-known anomalous post-earnings-announcement drift. However, the underreactions in analysts' forecasts are at most only about half as large as necessary to explain the magnitude of the drift. We also document that the “extreme” analysts' forecasts studied by DeBondt and Thaler (1990) cannot be viewed as overreactions to earnings, and are not clearly linked to the stock price overreactions discussed in DeBondt and Thaler (1985, 1987) and Chopra, Lakonishok, and Ritter (Forthcoming). We conclude that security analysts' behavior is at best only a partial explanation for stock price underreaction to earnings, and may be unrelated to stock price overreactions.

Tests of Analysts' Overreaction/Underreaction to Earnings Information as an Explanation for Anomalous Stock Price Behavior

This study examines whether security analysts underreact or overreact to prior earnings information, and whether any such behavior could explain previously documented anomalous stock price movements. We present evidence that analysts' forecasts underreact to recent earnings. This feature of the forecasts is consistent with certain properties of the naive seasonal random walk forecast that Bernard and Thomas (1990) hypothesize underlie the well-known anomalous post-earningsannouncement drift. However, the underreactions in analysts' forecasts are at most only about half as large as necessary to explain the magnitude of the drift. We also document that the "extreme" analysts' forecasts studied by DeBondt and Thaler (1990) cannot be viewed as overreactions to earnings, and are not clearly linked to the stock price overreactions discussed in DeBondt and Thaler (1985, 1987) and Chopra, Lakonishok, and Ritter (Forthcoming). We conclude that security analysts'

Overreaction / Underreaction to Earnings Information as an Explanation for Anomalous Stock Price Behavior

This paper studies the information links that connect detailed financial statement data and security prices. We establish empirically the underlying relations between rules of fundamental analysis and: 1) analysts' earnings forecast revisions, 2) actual future earnings changes and 3) security returns. We find evidence that some but not all of the fundamental signals are related to subsequent earnings changes and analysts' revisions as hypothesized. Paradoxically, contemporaneous security returns reveal that, in the eyes of investors, the set of fundamental signals contain information orthogonal to analysts' revisions. Additional evidence suggests one explanation for this result is that analysts' forecast revisions are inefficient with respect to the future earnings information contained in some of the fundamental signals. One practical implication of our findings is that if analysts were to process efficiently the information in the fundamental signals, it would be sufficient to eliminate the well-documented phenomenon of analyst underreaction to prior earnings news.

Fundamental Analysis Future Earnings, and Stock Prices

In this paper, we investigate how detailed financial statement data (fundamental signals) enter the decisions of market participants by examining whether current changes in the signals are informative about subsequent earnings changes. Our approach is consistent with the view expressed by Penman [ 1992] and others that predicting accounting earnings, as opposed to explaining security returns, should be the central task of fundamental analysis. Studying the links between fundamental signals and future earnings changes allows us to test directly the validity of the economic intuition that underlies the original construction of the signals. An alternative, and less direct, approach, followed by Lev and Thiagarajan [1993] (henceforth LT), is based on an examination of the relations between the fundamental signals and contemporaneous returns.

Fundamental Analysis, Future Earnings, and Stock Prices

https://deepblue.lib.umich.edu/bitstream/handle/2027.42/29294/0000355.pdf;sequence=1

Jeffery S. Abarbanell

Papers

Tests of Analysts' Overreaction/Underreaction to Earnings Information as an Explanation for Anomalous Stock Price Behavior

Overreaction / Underreaction to Earnings Information as an Explanation for Anomalous Stock Price Behavior

Fundamental Analysis Future Earnings, and Stock Prices

Fundamental Analysis, Future Earnings, and Stock Prices

Do analysts' earnings forecasts incorporate information in prior stock price changes?