We analyze the effects of synergies from horizontal mergers on managerial incentives. In contrast to synergies, efficiency gains resulting from managerial effort are not merger specific, i.e., they may be realized by all firms before and after a merger. We show that synergies suppress managerial...

We analyze horizontal mergers when the acquirer holds a passive partial ownership stake (PPO) in the target firm prior to the merger. We show that a PPO reduces the minimal synergy level necessary to make a merger beneficial for consumers. It follows that an antitrust authority ignoring existing...