Concentration-based screens for horizontal mergers, such as those employed in the US DOJ and FTC Horizontal Merger Guidelines, play a central role in merger analysis. However, the basis for these screens, in both form and level, remains unclear. We show that there is both a theoretical and an...

Concentration-based screens for horizontal mergers, such as those employed in the US DOJ and FTC Horizontal Merger Guidelines, play a central role in merger analysis. However, the basis for these screens, in both form and level, remains unclear. We show that there is both a theoretical and an...

The transaction cost approach to the organization of firms has been among the most significant advances in industrial organization in the last twenty-five years. Much of this work has taken the Transaction Cost Economics view of Williamson (1975, 1979, 1985) and Klein, Crawford, and Alchian...