The analysis of unilateral effects in horizontal mergers — especially on markets for differentiated goods — can take into consideration the extent to which the merging firms are close competitors. The elimination of a close competitor can result in an upward pricing pressure (UPP) on the...

The classical legal approach for distinguishing between illicit collusion and legitimate oligopoly conduct is to rely on proxies, such as elements of “practical cooperation”, on “plus factors”, or on the finding of an anticompetitive intent among rival firms. These criteria ultimately...