The American Express Decision and its Critics

The Supreme Court’s 2018 American Express (“Amex”) decision was its first involving two-sided platforms since the emergence of platform economics. As the Internet continues to facilitate the growth of two-sided businesses, cases involving them are likely to be both common and important. This essay first summarizes the core findings of the Amex decision and relates them to the economic literature. We then consider the main criticisms of that decision in light of platform economics. We argue