Selected Economic Analysis at the Antitrust Division: The Year in Review

Of the many activitiesof the Antitrust Division of theU.S. Department of Justice, we havesummarized some that raise interestingeconomic issues. We describe recentimprovements in the methodology to beused in ``coordinated effects' analysisof mergers. We also discuss four casesbrought by the DOJ that raise issues ofmarket definition, the influence ofcommon partial ownership of competitors,and the effects of fringe suppliers inconstraining collusion by large firms.