We show that divestitures accompanying horizontal mergers affect both the market power potential and the competitive efficiency of merging firms. Stock price reactions of customer firms are more positive (hence divestitures are more effective in mitigating the market power impact of the merger)...

We show that pharmaceutical mergers are a response to competitive pressure. Firms whose drugs face more competition tend to become acquirers and these acquirers pursue firms whose drugs hold strong competitive positions in their product spaces. However, we find no evidence of greater post-merger...