AmEx SCOTUS Case Could Shape Antitrust Market Analysis

The U.S. Supreme Court could shape how antitrust violations will be judged in complex markets, like health care or credit cards, when it rules on a case challenging American Express Co.’s merchant rules.

The Justice Department during the Obama administration sued American Express for illegally stopping merchants from asking customers to use cheaper credit cards. The U.S. Court of Appeals for the Second Circuit ruled against the government’s position last year, arguing that antitrust enforcers hadn’t considered both sides of a “two-sided market” that includes cardholders and merchants.

“It’s a potentially blockbuster case insofar as it gives the Supreme Court ...