A Geographic Market Power Test for Sherman Act Jurisdiction


This paper develops a clear and substantively reasoned test for Sherman Act jurisdiction based on the interstate exercise of market power. According to this test, to establish jurisdiction under the Act the plaintiff must allege that, if successful, the defendants' conduct is reasonably likely to raise prices "in more states than one." Local trade restraints that cannot plausibly be alleged to raise prices outside the home state therefore lie beyond the reach of the Sherman Act. The geographic market power test resolves a number of troubling anomalies in the case law on Sherman Act jurisdiction. It also takes seriously the Act's acknowledged goal of promoting consumer welfare and preserves the states' role as laboratories for political competition in our federal system of dual sovereignty.