Over the last two years, at least five people in the U.K. have been killed by American XL bully dogs, prompting no less than the prime minister himself to come forward with a plan to control the dogs.

The upshot of Prime Minister Rishi Sunak’s policy is that they will have to be registered, neutered, muzzled in public and insured, with an eventual ban to follow.

The decision offers some important lessons about regulation. First, sometimes an outright ban is better than charging owners or users a fee, or what economists call Pigou taxes. Under some economic theories, bans should be exceedingly rare. Instead, the government should charge a high fee for the right to own or use something. In this case, people who really want to keep their XL bully dogs will just pay more for a license.