In this comprehensive review of ex-post merger studies price effects of horizontal transactions are evaluated. By combining and further analyzing the results of 52 retrospective studies on 82 mergers or merger-like transactions it can be shown that the industry alone is no strong indication for...

U.S. antitrust law empowers enforcers to review pending mergers that might undermine competition. But there is growing evidence that the merger-review regime is failing to perform its core procompetitive function. Industry concentration and the power of dominant firms are increasing across key...

We analyze the optimal dynamic policy of an antitrust authority towards horizontal mergers when merger proposals are endogenous and occur over time. Approving a currently proposed merger will affect the profitability and welfare effects of potential future mergers, the characteristics of which...

This article explains the inherent loss of an indirect competitor and reduction in competition when a vertical merger raises input foreclosure concerns. We then calculate a measure of the effective increase in the HHI measure of concentration for the downstream market, and we refer to this...