The short and long term effects of large takeovers on the share price performance of acquiring companies listed on the JSE

Abstract

Whether mergers and acquisitions create or destroy shareholder value for acquiring companies has been widely researched and remains fairly inconclusive. The purpose of this research was to study the short term and long term impacts of large acquisitions on the share price performance of acquiring companies using the event study methodology.From a population of 11 062 acquisitions made by JSE listed companies between 1999 and 2008, 39 acquisitions met the relevant criteria of non-occurrence of confounding events and the availability of information. The Cumulative Abnormal Returns of acquiring companies over a short term period surrounding the announcement date and the longer term post-announcement date period were tested to observe whether they were significantly different to zero.Whilst statistically significant Cumulative Abnormal Returns were observed over the short term 3-day event window [-1;+1], no statistically significant Cumulative Abnormal Returns were observed around the remaining five event windows.