Market e#ciency survives the challenge from the literature on long-term return anomalies. Consistent with the market e#ciency hypothesis that the anomalies are chance results, apparent overreaction to information is about as common as underreaction, and post-event continuation of pre-event abnormal returns is about as frequent as post-event reversal. Most important, consistent with the market e#ciency prediction that apparent anomalies can be due to methodology, most long-term return anomalies tend to disappear with reasonable changes in technique. # 1998 Elsevier Science S.A. All rights reserved.

This paper was developed with financial support from the SBF Bourse de Paris and the New York Stock Exchange, and the assistance of George Sofianos, Bill Tschirhart, and Didier Davidoff is gratefully acknowledged. We appreciate comments received on this paper from Anthony Boardman, Bernardo Bortolotti, Narjess Boubakri, JeanClaude Cosset, Kathy Dewenter, Alexander Dyck, Ivan Ivanov, Ranko Jelic, Claude Laurin, Marc Lipson, Luis Lopez-Calva, John McMillan (the editor), Harold Mulherin, Rob Nash, John Nellis, David Newberry, David Parker, Enrico Perotti, Annette Poulsen, Ravi Ramamurti, Susan Rose-Ackerman, Nemat Shafik, Mary Shirley, Aidan Vining and three anonymous referees. Additionally, we appreciate comments received from participants at the NYSE/Paris Bourse Global Equity Markets conference (Paris, December 1998), the Harvard Institute for International Development Privatization Workshop (June 2000), the International Federation of Stock Exchanges' Third Global Emerging Markets Conference (Istanbul, April 2000), four World Bank and/or International Finance Corporation meetings, two OECD conferences (Paris and Beijing), the 1999 Conference on Privatization and the Kuwaiti Economy in the Next Century, the 1998 Financial Management Association meeting, the 1999 European Financial Management Association meeting, the Fondazione ENI Enrico Mattei (FFEM), the Swiss Banking Institute and Credit Suisse, and seminars at the City University Business School (London), London Guildhall University and the University of Oklahoma. All remaining errors are the authors' alone. Please address correspondence to: William L. Megginson Price College of Business 307 West Brooks, 205A Adams Hall The University of Oklahoma Norman, OK 73019-4005 Tel: (405) 325-2058; Fax: (405) 325-1957 e-mail:...

We analyze tests for long-run abnormal returns and document that two approaches yield well-specified test statistics in random samples. The first uses a traditional event study framework and buy-and-hold abnormal returns calculated using carefully constructed reference portfolios. Inference is based on either a skewnessadjusted t-statistic or the empirically generated distribution of long-run abnormal returns. The second approach is based on calculation of mean monthly abnormal returns using calendar-time portfolios and a time-series t-statistic. Though both approaches perform well in random samples, misspecification in nonrandom samples is pervasive. Thus, analysis of long-run abnormal returns is treacherous. COMMONLY USED METHODS TO TEST for long-run abnormal stock returns yield misspecified test statistics, as documented by Barber and Lyon ~1997a! and Kothari and Warner ~1997!. 1 Simulations reveal that empirical rejection levels routinely exceed theoretical rejection levels in these tests. In combination, these papers highlight three causes for this misspecification. First, the

We examine long-run firm performance following open market share repurchase announcements, 1980-1990. We find that the average abnormal four-year buy-and-hold return measured after the initial announcement is 12.1%. For ‘value ’ stocks, companies more likely to be repurchasing shares because of undervaluation, the average abnormal return is 45.3%. For repurchases announced by ‘glamour ’ stocks, where undervaluation is less likely to be an important motive, no positive drift in abnormal returns is observed. Thus, at least with respect to value stocks, the market errs in its initial response and appears to ignore much of the information conveyed through repurchase announcements.

A rapidly growing literature claims to reject the efficient market hypothesis by producing large estimates of long-term abnormal returns following major corporate events. The preferred methodology in this literature is to calculate average multi-year buy-and-hold abnormal returns and conduct inferences via a bootstrapping procedure. We show that this methodology is severely flawed because it assumes independence of multi-year abnormal returns for event firms, producing test statistics that are up to four times too large. After accounting for the positive cross-correlations of event firm abnormal returns we find virtually no evidence of reliable abnormal performance for our samples.

It is well known that firms are more likely to issue equity when their market values are high, relative to book and past market values, and to repurchase equity when their market values are low. We document that the resulting effects on capital structure are very persistent. As a consequence, current capital structure is strongly related to historical market values. The results suggest the theory that capital structure is the cumulative outcome of past attempts to time the equity market.

This paper analyzes the determinants of initial public offerings (IPOs) in Italy. We compare the ex ante and the ex post characteristics of IPOs with those of a large sample of privately held companies. The likelihood of an IPO is positively related to the company's size and the industry's market-to-book ratio. Companies appear to go public not to finance future investments and growth, but rather to rebalance their accounts after a period of high investment and growth. IPOs are also followed by a reduction in the cost of credit and an increased turnover in control. These findings highlight some important differences between the role played by the equity market in Italy (and likely in other Continental European countries) and in the United States. This paper is part of the research project on "The decision to go public and the stock market as a source of capital," promoted by the Ente "Luigi Einaudi" per gli studi monetari bancari e finanziari. The suggestions we received from Espen E...

The share of equity issues in total new equity and debt issues is a strong predictor of U.S. stock market returns between 1928 and 1997. In particular, firms issue relatively more equity than debt just before periods of low market returns. The equity share in new issues has stable predictive power in both halves of the sample period and after controlling for other known predictors. We do not find support for efficient market explanations of the results. Instead, the fact that the equity share sometimes predicts significantly negative market returns suggests inefficiency and that firms time the market component of their returns when issuing securities.

Seasoned equity issuers can raise reported earnings by altering discretionary accounting accruals. We find that issuers who adjust discretionary current accruals to report higher net income prior to the o#ering have lower post-issue long-run abnormal stock returns and net income. Interestingly, the relation between discretionary current accruals and future returns (adjusted for firm size and book-to-market ratio) is stronger and more persistent for seasoned equity issuers than for non-issuers. The evidence is consistent with investors naively extrapolating pre-issue earnings without fully adjusting for the potential manipulation of reported earnings. # 1998 Elsevier Science S.A. All rights reserved.

Carolina at Chapel Hill for helpful comments and suggestions and Jay Ritter and Michel Vetsuypens for We examine data on analyst following for a sample of initial public offerings completed over the 1975-1987 period to see how they relate to three well-documented IPO anomalies. We find that higher underpricing leads to increased analyst following. Analysts are overoptimistic about the earnings potential of recent IPOs and about their long term growth prospects. More firms complete IPOs when analysts are particularly optimistic about the growth prospects of recent IPOs. In the long run, IPOs have better stock price performance when analysts ascribe low growth potential to these firms than when they ascribe high growth potential. These results suggest that the anomalies documented in the IPO market may, at least partially, be driven by overoptimism. 1 1.