Many of my friends who defend public education are also the political type who are very worried about monopolies. They often point to the damage that companies with large market shares—think Amazon, Wal-Mart, and Google—can do. These friends point out how these companies’ large market presence allows them to squeeze out competitors, exploit employees, and hold customers captive.

Those points, of course, are debatable, but what really troubles me is that while these friends decry monopolies in commerce, they defend a huge monopoly: public schools. All the same criticisms should apply—but never seem to.