The litmus test for government antitrust actions has traditionally been the consumer-welfare standard developed by Robert Bork: If consolidated market power doesn’t lead to higher prices, consumers haven’t been harmed, and there’s no justification for government to act. By this view, Big Tech is off the hook. Its prices are low, sometimes free.

This view is too narrow. For one thing, digital networks with monopoly power can charge higher prices for advertisements, ultimately passed on to consumers.