Take the hospital system run by the Department of Veterans Affairs, the largest integrated health system in the United States. It is fully government run, much more “socialized medicine” than is Canadian health care with its private doctors and hospitals. And the system for veterans is by all accounts one of the best-performing and most cost-effective elements in the American medical establishment.

A study by the Rand Corporation concluded that compared with a national sample, Americans treated in veterans hospitals “received consistently better care across the board, including screening, diagnosis, treatment and follow-up.” The difference was particularly large in preventive medicine: veterans were nearly 50 percent more likely to receive recommended care than Americans as a whole.

“If other health care providers followed the V.A.’s lead, it would be a major step toward improving the quality of care across the U.S. health care system,” Rand reported.

As for the other big government-run health care system in the United States, Medicare spends perhaps one-sixth as much on administration as private health insurers, although the comparison is imperfect and controversial.

But the biggest weakness of private industry is not inefficiency but unfairness. The business model of private insurance has become, in part, to collect premiums from healthy people and reject those likely to get sick  or, if they start out healthy and then get sick, to find a way to cancel their coverage.

A reader wrote in this week to tell me about a colleague of hers who had health insurance through her company. The woman received a cancer diagnosis a few weeks ago, and she now faces chemotherapy co-payments that she cannot afford. Worse, because she is now unable to work and has to focus on treatment, she has been shifted to short-term disability for 90 days  and after that, she will lose her employer health insurance.