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 a framework where mergers are mutually excluding, I show that firms pursue anti- rather than (alternative) pro-competitive mergers. Potential outsiders to anti-competitive mergers refrain from pursuing pro-competitive mergers if the positive externalities from anti-competitive mergers are...

A government wanting to promote an efficient allocation of resources as measured by the total surplus, should strategically delegate to its competition authority a welfare standard with a bias in favour of consumers. A consumer bias means that some welfare increasing mergers will be blocked....