We consider a high-quality dominant firm facing a low-quality competitive fringe. We show that the dominant firm's quantity is (weakly) increasing in its quality if and only if its marginal cost (weakly) exceeds that of the fringe; otherwise it is strictly decreasing in quality. This result is...

Recent literature has shown that an incumbent can use exclusive contracts to maintain supra-competitive prices when buyers of the good are also competitors. Most of the models require the incumbent to completely prevent a more efficient potential entrant from entering, and assume that the...

When intervening in markets, say to block a merger, competition authorities are constrained by the limited information they have about the social desirability of the available alternatives. Compared to ex ante control, ex post control is based on the more accurate information that becomes...