Platforms, <i>American Express</i>, and the Problem of Complexity in Antitrust

I. Introduction II. The Great Generalization III. Antitrust Without Platform Theory ... A. Are Credit Cards Really a Boon to Society and Would Non-Platform Antitrust Wreck It? ... 1. Do Credit Cards Do Anything Special? ... 2. How a Platform Player Causes Harm on One Side ... B. Will the Cat Really Stay in the Credit Card Bag? IV. Conclusion: How Antitrust Complexity Devolves to Conservative Simplicity