The influence of systematic risk factors and econometric adjustments in catastrophic event studies

Event study methodology is a well-accepted technique in finance. Although its application is popular, there have not been many critical assessments of this practice. For instance, in the estimation process, the researcher has to make a choice in terms of which asset pricing model to adopt when calculating expected returns. Different expected return models and financial econometrics adjustments may give rise to different results. This study explores seven commonly employed approaches. Using terrorist attacks and the subprime crisis as events, we calculate abnormal returns with different expected return techniques and then assess if there is a change in the result. Our evidence shows that the results vary according to the choice of the technique in estimating an expected return.