According to a poll earlier this year in the New England Journal of Medicine, a majority of American physicians say that single-payer is the best path forward. Doctors are not traditionally a progressive bunch — in the 1960s, the American Medical Association famously hired Ronald Reagan to attack Medicare as “socialized medicine.” So why might this be?

A new study exploring the phenomenon of physician burnout holds some clues. Researchers from University of California, Riverside School of Medicine found that under the current system, doctors are increasingly unhappy at work. They observed a sharp rise in physician burnout, which they define as “1) a feeling of a lack of accomplishment; 2) feelings of cynicism; and 3) a loss of zeal, zest, and enthusiasm for work.”

One of the reasons for this dissatisfaction is that, as researcher Kenneth A. Ballou pointed out, “the doctor-patient relationship has been morphed into an insurance company-client relationship that imposes limitations upon the treatment doctors can provide to the insurance company’s members.” In our current system, there are usually three parties involved in every medical decision: the doctor, the patient, and the insurer. The doctor and patient may agree on a course of treatment, but the insurer decides whether it will be covered. And since many Americans can’t afford ever-growing out-of-pocket medical costs, that often means that insurers have the final say in whether the treatment will be administered at all.

The majority of Americans receive health coverage from a private insurance company. And while doctors and patients are both theoretically focused on patient health, the insurer is driven by an entirely different motivation: to maximize profit. Insurance companies are financially motivated to deny claims, and they do it all the time, even in life-or-death situations. One in four patients with a chronic or persistent illness or condition have had claims for medication, tests, or procedures denied by their insurer. In 70 percent of those cases, the condition was described as serious. Only 1 percent of patients said they trusted their health insurance provider’s judgment over their doctor’s or their own — and yet the buck stops with insurance companies.

When they deny claims, insurers give doctors and patients all kinds of excuses packaged in obscure industry terminology: formulary exclusion, prior authorization. But the simple fact is that patients aren’t getting the care they need — and doctors aren’t getting the opportunity to actually do their job. All too often, this is deadly for patients. For doctors, it’s depressing and demotivating. It hinders physicians’ ability to practice medicine, makes them feel powerless at work, and divests them of a feeling of personal accomplishment.

Another factor contributing to doctor burnout is depersonalization. Patients change doctors constantly under our current system. People switch jobs, or their employers switch insurers, and as a result patients are required to change networks and providers. Or people’s income fluctuates and they drift in and out of Medicaid eligibility, often going through periods where they aren’t insured at all. The ACA marketplaces are more or less designed to rupture relationships between doctors and patients, appealing to patients as consumers and communicating that if they shop around they can find a better plan, one that will finally meet all their needs — though it rarely does.

As a result of our jigsaw insurance network system, doctors and patients meeting for the first time can’t assume they’re embarking on a meaningful long-term relationship. “The doctor–patient relationship has sustained the happiness of both doctors and patients for generations,” write the UC Riverside researchers. “This centuries-old relationship has only recently been threatened by a de facto insurer–employer–provider relationship.” Seeing little purpose in getting to know patients intimately, doctors can become cynical. The lack of continuity leads to feelings of alienation and disinvestment for physicians who may have been attracted to the profession by the prospect of helping and healing people.

Finally, the study’s authors point to the proliferation of mandated use of Electronic Health Records (EHRs) as a cause of physician burnout. “No humanistic physician gets up with zeal in the morning, hopeful for a chance to have a meaningful relationship with Epic or MEDITECH,” they write. One time-motion study found that doctors spend twice as much time on EHR and desk work as on clinical face-time with patients. These medical records software programs are designed to facilitate documentation required for billing, more than for care itself. The upshot is that the clerical tasks associated with our byzantine insurance system take physicians away from the bedside and from practicing actual medicine.

This wouldn’t be the case if we had a simpler health care financing system — for instance if there were only one insurer, or single payer, for all patients. What makes the health system so complicated and time-consuming is that it’s carved up into private insurance networks, instead of a standardized system where a single public plan finances medical care for virtually everyone, as in dozens of other countries. Of course, the health insurance companies profit from this arrangement, and so does the rapidly growing health informatics sector intent on monetizing the management of our complex system. But there is no value for patients in private insurance — and, increasingly, doctors are finding that they too get the short end of the stick.

In a 2015 international survey of primary care doctors by the Commonwealth Fund, only 16 percent of US doctors said the US health care system “works pretty well and only minor changes are necessary,” while 14 percent said it “has so much wrong with it that we need to completely rebuild it” — versus 22 percent and 11 percent in the UK and 36 percent and 3 percent in Canada, both countries with single-payer systems.

Under a single-payer or Medicare for All system, there would be no private corporations with the motivation and the power to deny coverage just to improve their bottom line. In fact, since the government would be the sole financer of every individual’s care from cradle to grave, it would be incentivized to keep people healthy in ways that insurance companies — which play musical chairs with patients and ultimately hand them off to the government in old age — simply aren’t. Under a single-payer system, the insurer would want doctors to do their jobs and treat people, instead of thwarting them when financially convenient.

Moreover, under a single-payer system, nobody would change networks — because there wouldn’t be any networks. Doctors could build long-lasting, rewarding relationships with patients again. Between less time on billing paperwork, more continuity in care, and no private insurers prohibiting them from healing the sick, it’s really not so hard to see why physicians are warming to Medicare for All.