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...

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 externalilties 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. 

There is diverging empirical evidence on the competitive effects of horizontal mergers: consumer prices (and thus presumably competitors' profits) often rise while competitors' share prices fall. Our model of endogenous mergers provides a possible reconciliation. It is demonstrated that...

In intermediate goods markets, both buyers and sellers normally have market power, and sales are based on bilaterally negotiated contracts specifying both price and quantity. In our model, pairs of buyers and sellers meet in bilateral but interdependent Rubinstein-Ståhl negotiations. The...

This note provides sufficient conditions for immediate agreement in an extensive form model of interdependent bilateral bargaining. The model is suggested by Björnerstedt and Stennek (2006) as a work horse for studying bilateral oligopoly. The key feature of this model is that the firms are...

Markets with imperfect competition do not induce a cost-minimizing allocation of production between firms. The market's ability to rationalize production is even more limited if costs are private information to firms. Merger in such markets generate an efficiency gain associated with the pooling...