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...

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...