Evaluation of Event Study Methodology in Finance and Economics

Abstract

This paper deals with the fundamental issues faced by researchers in the application of the “event study methodology” to study the economic effects of long-term financial events and how the market responds to mergers and acquisitions, profit or debt announcements, corporate reorganization and investment decisions, and dividend announcements,…, since many studies in finance have provided evidence that companies can achieve longterm abnormal returns during a period of time between one and five years following important financial events, The long – term performance is considered a challenging area of research, than the short-horizon effect. Generally, the short-term trend is not exceeding several days after the financial event the main reason why the long-term yield is more difficult to measure is that the short-term expected daily return after the financial event will be close to zero, and the model used to measure the expected return will not have a significant impact on the statistical tests of the abnormal return. so, some statistical issues emerge, and that the measurement of the abnormal return on the long term will be subject to different statistical biasness. This research presents the most important models used to measure expected return. It also discusses the most important statistical tests showing their strengths and weaknesses in each model.