The Market Power Requirement in Antitrust Rule of Reason Cases: A Rhetorical History

Under section 1 of the Sherman Act,' on which this Article will focus, a central position for market power has been mandated neither by statute nor by the Supreme Court. Section 1 refers only to "contract[s] ... in restraint of trade,"' language that suggests no market power requirement. Nor has the Supreme Court imposed any general market power requirement under section 1. To be sure, the Court has imposed market power requirements in certain categories of section 1 cases, but they are only those cases in which the plaintiff proceeds under a per se theory.' Indeed, the Court has on several occasions specifically rejected a market power requirement in section 1 rule of reason cases.'