We demonstrate a "preemptive merger mechanism" which may explain the empirical puzzle why mergers reduce profits, and raise share prices. A merger may confer strong negative externalities on the firms outside the merger. If being an "insider" is better than being an "outsider", firms may merge...

Anticompetitive mergers increase competitors' profits, since they reduce competition. Using a model of endogenous mergers, we show that such mergers nevertheless may reduce the competitors' share-prices. Thus, event-studies can not detect anti-competitive mergers.

Anticompetitive mergers benefit competitors more than the merging firms. We show that such externalities reduce firms' incentives to merge (a holdup mechanism). Firms delay merger proposals, thereby foregoing valuable profits and hoping other firms will merge instead - a war of attrition. The...

The private and social efficiency of two "behavioral" coordination mechanisms is examined in this paper. In Cournot oligopoly, firms prefer immediate coordination on the Nash equilibrium (interpreted as a preplay communication) over the best-reply dynamics (and fictitious play) which converge to...

In many intermediate goods markets buyers and sellers both have market power. Contracts are usually long-term and negotiated bilaterally, codifying many elements in addition to price. We model such bilateral oligopolies as a set of simultaneous Rubenstein-Stahl bargainings over contracts...

The purpose of this report is to contribute to the analysis of two questions. Should a merger control system take into account efficiency gains from horizontal mergers, and balance these gains against the anti-competitive effects of mergers? If so, how should a system be designed to account for...

This report studies the importance of efficiency gains from horizontal mergers. A general theme throughout this report is that efficiency gains, and their pass-on to consumers, may vary substantially from merger to merger. For this reason it seems appropriate to reconsider current practice in...