Event-study methodology under conditions of event-induced variance

Abstract Many authors have identified the hazards of ignoring event-induced variance in event studies. To determine the practical extent of the problem, we simulate an event with stochastic effects. We find that when an event causes even minor increases in variance, the most commonly-used methods reject the null hypothesis of zero average abnormal return too frequently when it is true, although they are reasonably powerful when it is false. We demonstrate that a simple adjustment to the cross-sectional techniques produces appropriate rejection rates when the null is true and equally powerful tests when it is false.

[1]  John Mcconnell,et al.  Corporate capital expenditure decisions and the market value of the firm , 1985 .

[2]  Stuart Rosenstein,et al.  Outside directors, board independence, and shareholder wealth☆ , 1990 .

[3]  E. Ziegel.  Introduction to the Theory and Practice of Econometrics , 1989 .

[4]  John J. McConnell,et al.  Further evidence on the bank lending process and the capital-market response to bank loan agreements , 1989 .

[5]  K. Brown,et al.  Risk aversion, uncertain information, and market efficiency , 1988 .

[6]  Kenneth A. Froot.  Consistent Covariance Matrix Estimation with Cross-Sectional Dependence and Heteroskedasticity in Financial Data , 1989, Journal of Financial and Quantitative Analysis.

[7]  A. Kalay,et al.  Predictable events and excess returns: The case of dividend announcements , 1985 .

[8]  Larry Y. Dann.  Common stock repurchases : An analysis of returns to bondholders and stockholders , 1981 .

[9]  Daniel W. Collins,et al.  A COMPARISON OF ALTERNATIVE TESTING METHODOLOGIES USED IN CAPITAL-MARKET RESEARCH , 1984 .

[10]  Walter N. Torous,et al.  Investigating security-price performance in the presence of event-date uncertainty , 1988 .

[11]  C. Corrado.  A nonparametric test for abnormal security-price performance in event studies , 1989 .

[12]  J. Patell,et al.  Anticipated information releases reflected in call option prices , 1979 .

[13]  Jerold B. Warner,et al.  MEASURING SECURITY PRICE PERFORMANCE , 1980 .

[14]  W. Beaver.  The Information Content Of Annual Earnings Announcements , 1968 .

[15]  Jerold B. Warner,et al.  Using daily stock returns: The case of event studies , 1985 .

[16]  Dennis E. Logue,et al.  Foundations of Finance. , 1977 .

[17]  Stephen H. Penman,et al.  Insider Trading and the Dissemination of Firms' Forecast Information , 1982 .

[18]  Guy Charest,et al.  Dividend information, stock returns and market efficiency-II , 1978 .

[19]  Jeffry M. Netter,et al.  Triggering the 1987 stock market crash : Antitakeover provisions in the proposed house ways and means tax bill? , 1989 .

[20]  E. Fama,et al.  The Adjustment of Stock Prices to New Information , 1969 .

[21]  J. Patell.  CORPORATE FORECASTS OF EARNINGS PER SHARE AND STOCK-PRICE BEHAVIOR - EMPIRICAL TESTS , 1976 .