Efficiency isn’t a simple concept

As Ronald Coase pithily observed: “One important result of this preoccupation with the monopoly problem is that if an economist finds something—a business practice of one sort or other—that he does not understand, he looks for a monopoly explanation. And as in this field we are very ignorant, the number of ununderstandable practices tends to be very large, and the reliance on a monopoly explanation, frequent.” The possibility that non-standard practices sometimes had economizing purpose and effect was ignored or, worse, efficiency was regarded as the source of unfair competitive advantage.

– Oliver Williamson, talking about antitrust policy, but hinting at how hard it is to make universal statements about the practices in markets and hierarchies that are and are not “efficient”.