While exclusive dealing can be efficient, the Chicago School has also argued that it cannot be anticompetitive, or that it seldom is. That argument takes two forms; both are weak. First, a price-theory argument (“the Chicago Three-Party Argumentâ€) depends crucially on a special model of oligopoly and predicts that we will never see what we see. I show how simply replacing the embedded oligopoly model suggests new efficiency and anticompetitive motives for exclusive dealing; these motives differ markedly from those usually discussed. Second, “the Chicago Vertical Question†is a challenge to theories of anticompetitive vertical practices, including exclusive dealing. While that Question is salutary and helpful, its apparent force dissipates if we pay careful attention to externalities, as others have noted, and to the issue of alternatives versus benchmarks, as I describe below. Overall, economic logic does not support any general presumption that exclusive dealing is efficient.
