different markets. We focus on the interaction between the merger's effects on downstream efficiency and on buyer power in a … size discounts for the merged entity has no impact on consumer prices or on smaller retailers, unless the merger affects … “waterbed effects,” that is, each small retailer pays a higher average tariff if a buyer merger improves downstream efficiency …

We analyze mergers and entry in a differentiated products oligopoly model of price competition. Any merger that does … not yield efficiencies is unprofitable if it induces entry sufficient to preserve pre-merger consumer surplus. Thus … specific magnitudes of efficiencies and post-merger entry, and these combinations are identified from pre-merger market shares …

This paper argues that it cannot be taken for granted that any merger that raises consumer surplus also increases … merger can raise consumer surplus while harming social welfare. Within this framework, we show that such an outcome depends … on two conditions: the merger is between small firms (i.e., relatively inefficient firms) and it reduces concentration …

arising under current rules, including a notable lack of tax neutrality among merger forms. It proposes pragmatic revisions …

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 … surplus by using a completely myopic merger review policy that approves a merger today if and only if it does not lower …

This paper introduces the Werden-Froeb Index (WFI) to assist in evaluating merger-specific efficiencies in horizontal … mergers. The index measures the weighted average reduction in marginal costs required to restore pre-merger equilibrium prices … and quantities after the (full or partial) merger is consummated. The WFI is well defined, objective and robust, and it …