Do Mergers Result in Collusion?

We examine coordinated effects of mergers in the Swedish retail market for gasoline during the period 1986-2002. Despite significant changes in market concentration and many factors conducive to coordination, the empirical analysis shows that the level of coordination is low. In addition, statistical tests reject the hypothesis that mergers and acquisitions result in "coordinated effects". In particular, higher market concentration does not result in more collusive behavior and, consequently, the relevance of simple "checklists" in merger control can be questioned.