Last month, the states of Ohio, Connecticut, Idaho, Illinois, Iowa, Maryland, Michigan, Montana, Rhode Island, Utah, and Vermont asked the U.S. Supreme Court to review a Second Circuit judgment that allows American Express to prohibit merchants from encouraging customers to use lower-priced payment options. (More information on the states’ cert petition is available here.) Our amicus brief in support of the states’ request argues that the U.S. Supreme Court should grant review because the Second Circuit misapplied antitrust law when it placed American Express’s interests above consumer welfare and, more importantly, the case presents a question of profound economic significance for consumers.

Back in 2010, several states and the federal government sued American Express, MasterCard, and Visa under section 1 of the Sherman Antitrust Act alleging that the companies insulated themselves from competition by contractually prohibiting merchants from promoting or encouraging customers to use credit cards that charged lower swipe fees to the merchants. This practice allowed the companies to impose supracompetitive swipe fees on merchants, which the merchants recouped by raising prices for all customers. MasterCard and Visa settled and discontinued the practice. American Express, on the other hand, kept fighting but lost after a seven-week bench trial. On appeal, the Second Circuit reversed and ordered that judgment be entered in favor of American Express. We agree with the states that the U.S. Supreme Court should grant review and reverse the Second Circuit.

Over the past several decades, consumers have increasingly used credit cards to make purchases. In 2016 alone, consumers in the United States purchased a whopping $3.3 trillion worth of goods and services with credit cards. This has been a boon for credit card companies, which collect from merchants a percentage of every transaction in the form of a swipe fee—typically 1-4%. In 2016, credit card companies collected $70 billion in swipe fees. By stifling competition through anti-steering provisions, American Express is able to keep swipe fees artificially high and reap extraordinary profits at the expense of consumers.