The Post-Merger Performance of Acquiring Firms: A Re-examination of an Anomaly

The existing literature on the post-merger performance of acquiring firms is divided. We re-examine this issue, using a nearly exhaustive sample of mergers between NYSE acquirers and NYSE/AMEX targets. We find that stockholders of acquiring firms suffer a statistically significant loss of about 10% over the five-year post-merger period, a result robust to various specifications. Our evidence suggests that neither the firm size effect nor beta estimation problems are the cause of the negative post-merger returns. We examine whether this result is caused by a slow adjustment of the market to the merger event. Our results do not seem consistent with this hypothesis.