Abnormal returns (market model prediction errors) are the subject of many event studies in accounting and finance literature. Conditional on the event of interest, researchers have recently used cross-sectional regressions to examine relations between abnormal returns and firm specific variables. This paper demostrates that non-constant variences and covariances in market model residuals across firms introduced bias in the estimated slope coefficients of the independent variables, i.e., the expected signs of the estimated slope coefficients can be predicted a priori. A method is develope to removed the bias in the estimated slope coefficiets and is found to be effective. This method explicitly takes the dependence among abnormal returns across firms into account. Methods that assume abnormal returns across firms to be independent do not control for such bias.

Information evaluation, Information systems, Group decision making, Group performance

Asset valuation, Replacement costs, Fixed asset lives, Depreciation

Auditing, Extrapolation, Time-series, Cost variance

This paper differentiates between country risk--the probability that a country will default on its obiigations--and two forms of international banking risk: (1) the extent to which a bank's foreign activities affect the cost of equity capital; and (2) the extent to which a bank's foreign activities affect the probability of bankruptcy. The paper focuses on the latter form of international banking risk.Using Chebyshev's Inequality, it is pointed out that the risk of bankruptcy is influenced by the mean as well as the variance of the return distribution. Consequently, restrictions on the (international) composition of a bank's portfolio may increase rather than reduce the probability of bankruptcy.

This study proposes and implements a method of labour supply estimation which is appropriate when the sample contains unemployed and underemployed workers. The estimation method consists of excluding unemployed and underemployed workers from the sample and then using (to avoid selection bias) an extension of Heckman's approach to the case where two correlated selection rules generate the sample. Hausman's specification test is then used to determine whether ignoring constrained workers has led to biases in traditional labour supply estimates, and the empirical results suggest that previous estimates of several important parameters are biased. Since the biases go in the direction that would be predicted by the hypothesis that the unemployed and underemployed are constrained, the results support this hypothesis.

T. C. Langetieg, M. C. Findlay, L. F. J. da Motts, Multiperiod Pension Plans and ERISA, The Journal of Financial and Quantitative Analysis, Vol. 17, No. 4, Proceedings of the 17th Annual Conference of the Western Finance Association, June 16-19, 1982, Portland, Oregon (Nov., 1982), pp. 603-631

David C. Emanuel, James D. MacBeth, Further Results on the Constant Elasticity of Variance Call Option Pricing Model, The Journal of Financial and Quantitative Analysis, Vol. 17, No. 4, Proceedings of the 17th Annual Conference of the Western Finance Association, June 16-19, 1982, Portland, Oregon (Nov., 1982), pp. 533-554