Document Type

Working Paper

Publication Date



This paper makes two points. First, it describes the opinion as creating a mirror-image of the "per se" rulings, this time favoring defendants instead of plaintiffs. Second, however, it points out the narrowness of the decision. If the American Express opinion had created rules for all two-sided platforms it would have fundamentally changed much of antitrust law, by reaching so much of American commerce. For the concept of a two-sided platform is open-ended enough to conceivably describe businesses as diverse as malls, sports leagues, real estate agents, stock exchanges, and most tech platforms. However, the American Express opinion is narrower than this, and claims that the decision “immunizes” the major tech platforms from antitrust scrutiny are incorrect. It seems clear that firms like Google, Facebook, and Twitter are not covered by the American Express opinion. For the Court emphasized that credit-card companies are so-called “transaction platforms,” a subset of two-sided platforms. The opinion goes on to define transaction platforms as those that can’t provide a service to one side of the market independently – those that, by necessity, facilitate a “simultaneous” interaction between the two sides. As such, according to the Court, transaction platforms only compete with other transaction platforms.


Antitrust and Trade Regulation | Law