The Organization for Economic Cooperation and Development, which looks at a group of developed countries, has found that the United States pays substantially higher prices for doctors, hospital stays and prescription drugs than the rest of the group. Medicare pays less than the United States average, but not enough less to make up that difference.

Making the American health care system significantly cheaper would mean more than just cutting the insurance companies out of the game and reducing the high administrative costs of the American system. It would also require paying doctors and nurses substantially lower salaries, using fewer new and high-tech treatments, and probably eliminating some of the perks of American hospital stays, like private patient rooms.

The average family physician in the United States earns $207,000, according to the Medscape Physician Compensation Report. General practitioners in Britain, which has a single-payer system, earn an average pay of around $130,000. The gaps in pay for specialists are even bigger.

The Urban Institute report assumes that the Sanders plan would cut pay for doctors substantially, but not by half. That’s a reasonable assumption.

We also pay more for drugs than the rest of the world, but many experts think that a single-payer health plan could push down drug prices because drug companies earn such high profit margins. The Urban analysis assumes that the country could quickly get to prices 25 percent lower than what Medicare pays. (That change assumes a political revolution, of course, because the pharmaceutical companies are an extremely effective lobby.)

The Sanders campaign and its academic allies dispute some of the Urban Institute’s assumptions. A critique of the Urban analysis from David Himmelstein and Steffie Woolhandler, professors of public health at the City University of New York, argues, for example, that drug prices could be pushed even lower. And the Sanders team says that the researchers overestimated the costs associated with administering the government program. But it doesn’t argue that the prices paid to medical providers could be cut more sharply.

The same problem exists for other attempts to reduce health spending in the United States. Efforts by the Obama administration to pay doctors and hospitals differently are designed to squeegee some waste out of the system, by eliminating extra care that may not help people’s health. But it has done little to change the prices paid for medical care. That means that its best hope is to “bend the cost curve,” or reduce the rate that health spending grows.