Trinko Meets Microsoft: Leverage and Foreclosure in Platform Refusals to Deal

Large platforms are often accused of refusing to serve (or discriminating against) competing sellers in adjacent product markets. Antitrust law labels such activity a unilateral “refusal to deal” (“RTD”) and evaluates it under a predation-like framework shaped by the two leading RTD cases, Aspen and Trinko. However, this framework is largely unhelpful in evaluating platform RTDs, because it does not ask the right economic questions. The relevant economic risk raised by pla