Fomby, Thomas B.; Murfin, Justin R. - In: Applied Financial Economics Letters 1 (2005) 4, pp. 239-242
Careless users of software with HAC adjustment should beware. In particular, in event study models with pulse dummies included as explanatory variables, the study shows that, in the presence of i.i.d. errors, HAC-adjusted t -statistics on the event dummies have divergent distributions and can,...