Read more: How economists’ faith in markets broke America

The irony is that the free-market ideas and business models that benefit European consumers today were inspired by American regulations circa 1990. Meanwhile, in industry after industry in the United States—the country that invented antitrust laws—incumbent companies have increased their market power by acquiring nascent competitors, heavily lobbying regulators, and lavishly spending on campaign contributions. Free markets are supposed to punish private companies that take their customers for granted, but today many American companies have grown so dominant that they can get away with offering bad service, charging high prices, and collecting, exploiting, and inadequately guarding their customers’ private data.

In Europe, greater integration among national economies turned out to be a force for greater competition within individual economies. The very same politicians who disliked free markets at home agreed to promote them at the European level. Why? Because everyone understood that the single market required independent regulators as well as a commitment that individual countries would not subsidize their domestic champions.

As it turned out, politicians were more worried about the regulator being captured by the other country than they were attracted by the opportunity to capture the regulator themselves. French (or German) politicians might not like a strong and independent antitrust regulator within their own borders, but they like even less the idea of Germany (or France) exerting political influence over the EU’s antitrust regulator. As a result, if they are to agree on any supranational institution, it will have a bias toward more independence.

The case of the industrial giants Alstom and Siemens provided an almost perfect test of my theory. After Germany’s Siemens and France’s Alstom decided in 2017 to merge their rail activities, the EU’s two largest and most influential member states both wanted the merger approved. But the EU’s powerful competition commissioner, Margrethe Vestager, stood her ground. She and her team concluded that the merger “would have significantly reduced competition” in signaling equipment and high-speed trains, “depriving customers, including train operators and rail-infrastructure managers, of a choice of suppliers and products.” The European Commission blocked the merger in February 2019.

In the United States, meanwhile, antitrust enforcement has become less stringent, while the debate over market competition has become highly ideological and untethered from what data actually show.

A central argument of the Chicago school of antitrust—whose laissez-faire approach was influential in persuading American regulators to take a more hands-off attitude toward mergers—is that monopoly power is transient because high profits attract new competitors. If profits rise in one industry and fall in another, one would expect more entry of new firms in the former than in the latter. This used to be true—until the late 1990s.