endogenous and occur over time. Approving a currently proposed merger will affect the profitability and welfare effects of …We analyze the optimal dynamic policy of an antitrust authority towards horizontal mergers when merger proposals are … surplus by using a completely myopic merger review policy that approves a merger today if and only if it does not lower …

post-merger efficiency improvements to reveal a new margin of adjustment along the product dimension. We analyze horizontal … between differentiated varieties. After a merger, acquirers drop products from their consolidated domestic product portfolio … and reallocate assets towards core varieties. We further demonstrate that such merger-induced efficiency gains imply …

post-merger efficiency improvements to reveal a new margin of adjustment along the product dimension. We analyze horizontal … between differentiated varieties. After a merger, acquirers drop products from their consolidated domestic product portfolio … and reallocate assets towards core varieties. We further demonstrate that such merger-induced efficiency gains imply …

segments close to the merger’s industry. These segments appear to have higher Tobin’s Q. Firms with greater R&D increases …

aggregate variety increases following a merger. However, with fixed cost synergies, an increase in aggregate variety can … indicate that the merger is beneficial. Our results also show high synergies do not necessarily improve consumer welfare. …