The very idea of living individuals selling body parts prompts revulsion in some people, while others may ask whether the price is right.

A recent nbcnews.com article reported on an organ-transplant study conducted by Canadian researchers. It began with this finding: “Paying living kidney donors $10,000 to give up their organs would save money over the current system based solely on altruism—even if it only boosts donations by a conservative 5 percent.”

Actually, the people selling their kidneys are not properly considered donors; they are “vendors.” Kidney selling is illegal in every country in the world, except Iran.

The shortage of available kidneys for transplantation leaves many people on burdensome dialysis for years, while others die awaiting a functioning kidney. Still, a thriving business takes place underground and in black markets worldwide.

Author Janet Radcliffe Richards, a professor of practical philosophy at Oxford University in the U.K., confronts the issue head-on in a book published late last year. She asks, “Would a legal, regulated market increase the supply of kidneys for transplantation while protecting the rights and welfare of the vendors?” She claims that her book — The Ethics of Transplants: Why Careless Thought Costs Lives — provides sound arguments for ending legal prohibition, but is not a direct plea for mounting campaigns to induce people to sell their kidneys.

Most of her arguments are persuasive. She rightly points out that we cannot draw any conclusions from the current situation about how a regulated market would work, since most of the unsavory conditions in the black market could be eliminated. She also asks why we should deny poor people the chance at a better life, citing the example of a Turkish man who sold one of his kidneys to pay for his daughter’s lifesaving medical treatment.

The book also argues against the usual contentions that offering so much money to people coerces them into selling their kidneys; that a market in kidneys would exploit the poor for the benefit of the rich; that the practice would commodify the human body; and that organ selling is “against human dignity.”

Richards observes that people are permitted to do all sorts of risky things for recreation (hang gliding, sky diving, extreme sports) — activities that are much riskier than removal of a kidney by a skilled surgeon in a hygienic operating room. Isn’t it ethically acceptable to respect the autonomy of individuals who want to earn money by doing something that would help others?

She challenges readers to come up with an ethical principle that can justify the continued prohibition of organ selling when people are permitted to sell other things that are their property. And she argues — conceptually correctly — that an offer of money is not coercive, since coercion requires that victims be made worse off whichever option they choose. She rebuts the exploitation argument, since only when people are not paid enough for their work (as in sweatshop labor) are they exploited. According to the Canadian research mentioned earlier, $10,000 might be a reasonable amount for a kidney.

Along with its article, NBC asked, “Should kidney donors be paid?” The answers: 21,462 people responded; 76 percent said “yes,” 16 percent said “no,” and 8 percent said “I don’t know.”

After examining the arguments for and against, I am left with a deep-seated feeling — call it intuition or a gut reaction — that even a well-regulated market in kidneys is ethically wrong. Perhaps this stems from the view that some things simply should not be bought and sold — such as babies. Or perhaps it’s my doubt about the supposition that the lives of kidney vendors would most likely be better off after the sale. They would likely pay off their debts but then go into debt again — minus one kidney.

I believe that intuition and gut reactions do not provide a reliable guide to ethical action. Yet, even though kidney selling is illegal in all countries except Iran, I have been unable to identify a sound ethical principle that justifies such a prohibition. Provided that the markets could be legally regulated, is there any sound ethical argument out there for preventing a potentially lifesaving, mutually beneficial exchange?

Ruth Macklin is a professor, department of epidemiology and population health, Albert Einstein College of Medicine. She blogs at The Doctor’s Tablet.