There are legal grounds to hear competitors in merger control proceedings, and competitor involvement has gained significance. To what extent this is economically sensible is our question. The competition authority applies some welfare standard while the competitor cares about its own profit. In...

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....

We analyze the optimal dynamic policy of an antitrust authority towards horizontal mergers when merger proposals are endogenous and occur over time. Approving a currently proposed merger will affect the profitability and welfare effects of potential future mergers, the characteristics of which...