In the New York Times, Margot Sanger-Katz kicks the tires on Bernie Sanders’s just released health care plan and the details, or rather the lackthereof, are not encouraging:

The plan, released two hours before Sunday night's Democratic debate, was full of details about the taxes that would be collected to finance it. The plan would charge a special income tax, called a premium, increase payroll taxes and raise a variety of taxes on high-income Americans, including income and capital gains taxes. Missing, however, were more than a few sentences about how the proposal would change the health care system in the United States.

Sanger-Katz notes that the missing details are far from trivial:

A lot of important details have been left out. Here are some things it doesn't say: What would the new system pay doctors and hospitals for their services? How would it decide which medical treatments it should and shouldn't cover? What strategies would it use to contain health care costs and keep the system affordable? Who would make the decisions, big and small, about how the program would work?

Even Gerald Friedman, an economics professor at the University of Massachusetts at Amherst, who ran the numbers on the plan for the Sanders campaign, has no idea how it is supposed to work:

Mr. Friedman calculates, for example, that the cost of physician services in a single-payer system could be lowered by 10.7 percent — his estimate of how much doctors currently spend on billing and administration staff that they would no longer need. I asked him how the payer would get to that number — would the government pay lower prices for treatments, or change which treatments it paid for, or switch doctors to a system in which they earn government salaries? He couldn't say with certainty. "The pleasure of being an academic is I can just spell things out and leave the details to others," he said. "The details very quickly get very messy."

Proposing "Medicare for all" sounds good, but insofar as Sanders's campaign has spelled things out, his proposal doesn't look much like Medicare. In fact, along with various other aspects of the program, the plan does away with co-pays and deductibles so it doesn't look like Sanders is much concerned with moral hazard or other issues that drive up the cost of Medicare. Already Medicare is responsible for over $40 billion in unfunded liabilities, and the annual cost of the program is roughly equivalent to the GDP of Argentina.

Sanders may be a principled leftist, but proposing such radical changes without even beginning to make a good faith effort to explain how they would work is irresponsible.