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 Argument”) 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.

Physical telecom networks are costly and few, traditionally to the point of monopoly. Innovation thrives with many independent minds. So one might hope independent innovators, not only its proprietor M, can offer innovative services on a network, as has been true on the Internet. This issue is central in telecom policy; it also arises elsewhere, including complaints about Microsoft. I try to expound the following key points. Often an unregulated M has ex ante incentives to organize service innovation efficiently. But this incentive breaks down ex post as M can extract an independent J’s quasi-rents (Farrell and Michael Katz 2000). Even ex ante, the "one monopoly rent theorem" (Ward Bowman 1957) fails when M’s bottleneck access business is more regulated than its competitive services (e.g., Jean-Jacques Laffont and Jean Tirole 2000). This tempts M to sabotage J’s innovations. "Quarantining" M from the service sector solves these problems, but excludes the firm with (often) the best opportunities and the strongest incentives to innovate. "Parity pricing" or ECPR (Robert Willig 1979) purports to get the best of both worlds (BoBW). But it seems so hard to implement in innovation markets that one might construe ECPR analysis as reductio ad absurdum for BoBW.

Physical telecom networks are costly and few, traditionally to the point of monopoly. Innovation thrives with many independent minds. So one might hope independent innovators, not only its proprietor M, can offer innovative services on a network, as has been true on the Internet. This issue is central in telecom policy; it also arises elsewhere, including complaints about Microsoft. I try to expound the following key points. Often an unregulated M has ex ante incentives to organize service innovation efficiently. But this incentive breaks down ex post as M can extract an independent J’s quasi-rents (Farrell and Michael Katz 2000). Even ex ante, the "one monopoly rent theorem" (Ward Bowman 1957) fails when M’s bottleneck access business is more regulated than its competitive services (e.g., Jean-Jacques Laffont and Jean Tirole 2000). This tempts M to sabotage J’s innovations. "Quarantining" M from the service sector solves these problems, but excludes the firm with (often) the best opportunities and the strongest incentives to innovate. "Parity pricing" or ECPR (Robert Willig 1979) purports to get the best of both worlds (BoBW). But it seems so hard to implement in innovation markets that one might construe ECPR analysis as reductio ad absurdum for BoBW.

Physical telecom networks are costly and few, traditionally to the point of monopoly. Innovation thrives with many independent minds. So one might hope independent innovators, not only its proprietor M, can offer innovative services on a network, as has been true on the Internet. This issue is central in telecom policy; it also arises elsewhere, including complaints about Microsoft. I try to expound the following key points. Often an unregulated M has ex ante incentives to organize service innovation efficiently. But this incentive breaks down ex post as M can extract an independent J’s quasi-rents (Farrell and Michael Katz 2000). Even ex ante, the "one monopoly rent theorem" (Ward Bowman 1957) fails when M’s bottleneck access business is more regulated than its competitive services (e.g., Jean-Jacques Laffont and Jean Tirole 2000). This tempts M to sabotage J’s innovations. "Quarantining" M from the service sector solves these problems, but excludes the firm with (often) the best opportunities and the strongest incentives to innovate. "Parity pricing" or ECPR (Robert Willig 1979) purports to get the best of both worlds (BoBW). But it seems so hard to implement in innovation markets that one might construe ECPR analysis as reductio ad absurdum for BoBW.