By Benjamin Klein –
The recent Amex decision emphasizes that antitrust analysis of vertical restraints used in two-sided platforms must consider both sides of the platform. This does not mean that the anticompetitive effects of restraints should be measured by aggregating the net price over the two sides. Instead, consistent with the established U.S. antitrust law of vertical restraints, a determination must first be made that the platform possesses market power. Once the overall platform exceeds a minimum market share screen, the potential anticompetitive effects of the vertical restraints should then be evaluated on the side of the platform where the restraints operate. However, contrary to the Amex dissent, this does not involve a determination of whether the price on that side of the platform is higher than it otherwise would be. Instead, one must determine if the vertical restraints distort the competitive process to maintain or enhance platform market power.
