<i>AmEx</i> and Post-Cartesian Antitrust

I. Introduction II. Situating American Express ... A. Different Sides of the American Express Opinion ... 1. Two-Sided Markets ... 2. The American Express Opinion ... B. The Real Issue Is Messy, Not Two-Sided, Markets … C. The Many Messes of Modern Markets III. Competition in Messy Markets ... A. Simple Competition in Simple Markets ... B. More Complex Competition in Messier Markets ... C. American Express: The Competition Is in the Pudding IV. The Many Sides of AmEx’s Rightness ... A. A Burden Best Born by Plaintiffs ... B. Economic Theory as a Question of Law or of Fact? V. Conclusion