We study upstream horizontal mergers and their potential efficiency gains. We show that an upstream horizontal merger can give rise to two efficiency-enhancing effects when firms trade through two-part tariffs. It increases R&D investments and decreases wholesale prices when downstream...

We re-examine the “buyer power” defense to horizontal mergers using models of imperfect competition in which input prices are set before goods prices. We derive a measure of unilateral incentives to adjust input prices after a downstream merger, Input Pricing Pressure, and we use it to show...

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...