EU Merger Control Regulation No 4064/89 tended to rely on a dominance test, based on the market share of undertakings, to indicate the level and potential changes in market power. The use of such in differentiated product industries is questionable. New EC Merger Regulation No 139/2004...

Worldwide, the overwhelming majority of large horizontal mergers are cleared by antitrust authorities unconditionally. The presumption seems to be that efficiencies from these mergers are sizeable. We calculate the compensating efficiencies that would prevent a merger from harming consumers for...

An increasing body of empirical evidence is documenting trends toward rising concentration, profits, and markups in many industries around the world since the 1980s. Two major criticisms of these studies is that concentration and market shares are poorly measured at the national industry level...

We examine how different pass-through rates, from input- to final consumer prices, and different vertical contracts affect upstream market definition. Our theory model predicts that, under reasonable conditions, higher pass-through rates lead to definitions of larger upstream markets. Data...