Divestitures have long been the preferred remedy for horizontal mergers, where there's an overlap between the two companies. Airlines, for example, may have to sell routes or airport gates where the two airlines compete; cable operators may have to sell operations in cities where both companies operate.

A large and growing body of academic research suggests there are market anomalies that can be exploited to beat a strict index approach. Some of that research has been recognized with Nobels in economic science - William F. Sharpe in 1990 and Eugene F. Fama in 2013.

A study by the Federal Trade Commission found that concerns about every vertical merger examined by the commission from 2006 to 2012 were resolved through 'conduct remedies' rather than divestitures, and that all these remedies had been successful at protecting competition.

James B. Stewart Quotes