The case for organ sales argued by Becker is compelling. The shortages, queuing, black market, cumbersome nonmarket allocation schemes, and quality problems that he describes are the classic symptoms of price controls: in this case a zero price limit for the sale of an organ.
I have just a few brief thoughts to add.
A puzzle is that "opt out" systems, used for example in France, whereby cadaver organs are automatically available for harvesting for transplant purposes unless an individual indicates (for example when receiving his driver‚Äôs license) that he doesn't want that, yield a significant increase in donations compared to our "opt in" ystem. The cost of opting out is trivial; why then could a shift from opt in to opt out have any significant effect? Yet the Abadie and Gay study that Becker cites indicates, after correcting for other factors, that an opt out ("presumed consent") system increases cadaver donations by 25 to 30 percent. (In later work, Gay has reduced this estimate.) As the authors point out, however, an increase in cadaver donations would presumably reduce the number of donations from living people, so the net effect on donations is uncertain. As the authors also realize (and attempt to correct for, while recognizing the difficulty of succeeding in the attempt), the adoption of an opt-out system may reflect, rather than cause, a propensity to donate organs.
One possible reason the weak default rule appears to have a significant effect is public ignorance. The probability that one's organs will be harvested for use in transplantation must be very slight--so slight that it doesn't pay to think much about whether one wants to participate in such a program. When the consequences of making a "correct" decision are slight, ignorance is rational, and therefore one expects default rules to have their greatest effect on behavior when people are ignorant of the rule and therefore do not try to take advantage of the opportunity to opt out of it. In this regard, it is perhaps significant that the countries with high rates of organ donation tend also to be countries with abnormally high traffic fatalities.
Becker mentions that in an effort to minimize the bad effects of the shortage of organs for transplantation, the U.S. government has given priority to the patients who would benefit from the transplant the most, as determined by medical personnel. This is an ambiguous and questionable criterion. The patient who is deemed to benefit the most from a transplant might be someone who was in such poor health that the transplant would merely prolong his life by a few months, whereas another patient, who was in better health, might gain added years from a transplant but without one would die soon--sooner than the unhealty patient, who might therefore be thought the one who would benefit the most from the transplant.
The legal ban on the sale of organs is part of a broader social policy of limiting "commodification," or propertization, of many valuable goods and services: or in other words of limiting the scope of the free market. Among such limitations that command essentially universal assent in our society: people may not agree to engage in gladiatorial contests in which they fight for the death, to sell themselves into slavery, to agree to have their knees broken if they default on a loan, to buy certain mind-altering drugs, to buy or sell sex, or to sell their parental rights. The grounds that are offered for these various limitations on the free market often have a certain plausibility, but do not seem adequate to explain the revulsion that the idea of the prohibited transactions arouse in most people. The transactions may have third-party effects or be the product of ignorance, shortsightedness, or lack of self-control, but this is true of many transactions that are permitted, such as drinking alcohol and gambling. It seems that the prohibited transactions are prohibited because they are highly offensive to nonparticipants; why they are highly offensive remains to be explained.
One form of organ commodification that remains to be considered is an enforceable contract to bequeath one's organs upon death to an organ depositary. Then the donor would receive money up front without having to give up his organ until death. The price would undoubtedly be low. The problem is enforcement: there would need to be a mechanism by which to inform the depositary promptly of the donor's death. But this problem should not be insuperable; the name and address of the depositary could be indicated on the donor's driver's license or (together with the donor's name) on some central registry to which police and paramedics would have access. Moreover, the existence of such a depositary is probably presumed by any market system in organs; one would not expect the patient to be negotiating directly with a potential donor, rather than dealing with an intermediary.