An integrative approach for examining the determinants of abnormal returns: The cases of Internet security breach and electronic commerce initiative.
Researchers in various business disciplines use the event study methodology to assess the market value of firms through capital market reaction to news in the public media about the firm's activities. Capital market reaction is assessed based on cumulative abnormal return (sum of abnormal returns over the event window). In this study, the event study methodology is used to assess the impact that two important information technology activities, Internet security breach and ecommerce initiative, have on the market value of firms. While prior research on the relationship between these business activities and cumulative abnormal return involved the use of regression analysis, in this study, we use decision tree induction and regression.