What if a simple policy could save tens of thousands of people every year from a deeply unpleasant treatment followed by early death? A policy that would disproportionately help the most disadvantaged? While actually saving taxpayer money?

That’s a pretty rare combination; presumably you’d be pretty excited. But what if the policy involved paying people to donate one of their kidneys to a stranger?

Possibly you are now less excited. Possibly you are now picturing a sci-fi dystopia where the poor serve as organ farms for the wealthy. Which is what such people as Gabriel Danovitch worry about. Danovitch, medical director of the Kidney and Pancreas Transplant Program at the Ronald Reagan UCLA Medical Center, believes more should be done to make organ donation financially neutral, compensating donors only for matters such as travel and lost wages. But he adamantly opposes letting donors profit from the transaction, because it would mean exploiting the desperate.

Letting people sell a kidney, he told me, would be not only ethically but also medically irresponsible. Desperate people would be tempted to lie about their medical history to qualify as a donor. Those lies could end up killing either the donor or the immune-suppressed recipient, whose body could no longer fight off stray germs or cancer cells.

Moreover, Danovitch says, paid donation would substitute for voluntary donation rather than adding to it. Why give your dad a kidney if you know one can be bought for him?

All valid concerns. But Frank McCormick calls our attention to another concern: the tens of thousands of people who are dying each year for want of a kidney. An economist by training, McCormick argues that if you keep ratcheting up compensation, eventually you’ll find a price that will clear the kidney “market.”

McCormick is one of the authors of a recent editorial in the Journal of the American Society of Nephrology that estimated a staggering toll for that backlog: Of 126,000 people diagnosed annually with end-stage renal disease, only 20,000 will eventually receive a donated kidney, either from donors who have been declared brain-dead or — since people can live a normal life span with only one kidney — from live donors who have accepted a relatively small chance of complications in exchange for a high chance of saving someone’s life.

Patients who need a kidney but can’t find a donor generally end up tethered to a dialysis machine every other day. But dialysis is a poor substitute for a functioning kidney, and five years after starting treatment, only a third of hemodialysis patients are still alive.

Dialysis is also an expensive kidney substitute, costing roughly $90,000 a year, most of it covered by Medicare; transplants cost less than half that. Which means, McCormick notes, that the government could compensate donors handsomely while still saving money. And because kidney failure disproportionately affects the poor, they on net would be better off, not worse off.

Moreover, he says, there are ways to mitigate other problems, such as patient education and waiting periods to weed out the truly desperate. What risks remain are small compared with the benefits of finding a kidney for every eligible patient.

That utilitarian calculus seems overwhelming. But most people aren’t pure utilitarians; they have moral intuitions that can’t be reduced to numbers. Including: Buying body parts is wrong.

“It’s about health and welfare,” says Danovitch of his transplant work. “We’re not talking about a financial interaction.”

But ... aren’t we? Transplant surgeons make hundreds of thousands of dollars a year for their work. In fact, everyone in the operating room except the donor is getting handsomely rewarded.

Instead, we’ve created a liminal social institution where altruism meets markets: “the healing professions.” The join is imperfect — yet it’s still better than the alternative. Nor is health care the only such space. Military recruiters, for example, offer hefty bonuses and generous veterans benefits as an incentive for civilians to join up.

Like soldiers, kidney donors accept some risk of bodily harm. If paying them outright is too repugnant, why not try treating them like veterans, with the similar hiring preferences, scholarships and so forth? Undoubtedly some people would donate for the wrong reasons, just as some people foolishly enlist. Yet that risk still seems preferable to leaving so many desperate dialysis patients dependent on the kindness of strangers.

Follow Megan McArdle on Twitter, @asymmetricinfo.