The decision to be an organ donor may seem easy for some: You sign an agreement that will let your heart, kidneys, liver, pancreas and other organs be used after your death in a way that helps the recipients lead fuller, healthier lives.

But for other people, the choice is harder. Some fear that a doctor may not work as hard to save them because he or she wants their organs for other patients, or that their organs might be removed prematurely (although there is no evidence to support either of these concerns). There may also be a psychological cost of having to think about your own death at a time when you are still relatively healthy. Other people may simply not want to bother with a program that doesn’t directly benefit them.

It is against this backdrop that Wharton business and public policy professor Judd Kessler and Harvard economics professor Alvin Roth set out to see whether changes in the management of organ waiting lists could increase the number of donors.

Organ banks would no doubt agree on the need for such changes. Only 40% of eligible Americans sign up to be organ donors, despite the fact that more than 110,000 patients in the U.S. are currently waiting for organ transplants. Organ donation rates for Texas and New York, the second and third most populous states, are only 7% and 15%, respectively.

The death of an unregistered donor means that medical caregivers must ask next of kin, usually during times of emotional distress, for permission to remove organs for transplant. In New England, organ transplant experts recover organs from only 50% of eligible candidates who are not registered donors. Because the act of registering is considered legal consent, the recovery of organs is always possible when the deceased is a registered donor.

In their research, Kessler and Roth decided to test whether an organ allocation policy that gives priority on waiting lists to those who register as organ donors would result in a significant change in registration numbers. “The underlying economic rationale,” says Kessler, “is that by providing priority on the waiting list, you are giving an incentive to register as a donor.” A similar priority system already exists in Singapore and is currently being implemented in Israel.

The researchers present their conclusions in a paper titled, “Organ Allocation Policy and the Decision to Donate.”   

One Brain and Two Kidneys

Since Kessler and Roth could not easily do an experiment with real organ donors, they created a game — played by students in a laboratory — that mimicked the decision to register as a donor. “We chose not to describe the game in terms of organ donation, but we kept the same characteristics,” notes Kessler. For example, each player had an “A” unit representing a brain and two “B” units representing kidneys, although the words “brain” and “kidney” were not used.

In the experiment, subjects played the organ donation game in groups of 12. They earned money for every period that they had an active A unit and at least one active B unit (i.e., every period they were healthy with an active brain and kidney). In each period, there was a probability their A unit would fail (i.e., that they would die from head trauma, making the organs available for transplant) or their two B units would fail (i.e., they would suffer from kidney failure).

Before subjects knew what would happen to their A and B units in that round, they were given an opportunity to register as a donor, so that if their A unit failed before their B units, their two B units could be transplanted to other people in the group. Agreeing to be a donor cost the subjects a small part of their monetary payout, regardless of whether a subject’s A unit failed before his or her B units. “We do not know exactly what the costs of registering as an organ donor are, so in the experiment we modeled them as a simple monetary cost, the same way we modeled the utility flow from being alive,” says Kessler. 

Subjects whose A unit failed were out of the game for that round and stopped earning money (i.e., they died). Meanwhile, a subject who had a healthy A unit but whose B units had failed could survive for up to five periods without an active B unit. In these periods, they did not earn any money, resembling the costs of being sick and on dialysis. If they did not receive a B unit in those periods, they were out of the game for the round. If these subjects received a B unit from someone else in their group at some time during those five periods, however, they could start earning money again.

The organ allocation rule, which determines how B units are distributed within the group, was the variable of interest that Kessler and Roth manipulated in the experiment.

In the control condition, B units were distributed by a first-come,first-served waiting list, as is the standard in the U.S. today. Those who had been waiting the longest (and were closest to the five-period deadline) received B units first. Then any remaining B units were given to people who had been waiting slightly less long, and so on down the list.

In the priority condition, B units were given first to subjects who had agreed to be donors at the beginning of the round. Essentially, the organ allocation rule had a priority group made up of people who had paid the cost of registering as a donor. Within that group, subjects received B units on a first-come, first-served basis. But only if all subjects who were registered donors had received B units did any non-registered donors get one, even if that meant a non-donor was about to expire in the next round.

When Kessler and Roth introduced this priority policy, either at the beginning of the game or somewhere in the middle, willingness to pay the cost of donation shot up over 100%, to between 70% and 80% of subjects registering to donate.

The researchers introduced two other conditions — which gave either a discount or a rebate for agreeing to donate — in an attempt to figure out why the priority rule was working. The discount and the rebate conditions provided monetary incentives to register as a donor that were calibrated to be the same size as the monetary benefit of having priority. When subjects had experience with the game, these monetary incentives worked just as well as giving priority to donors, suggesting that the priority rule worked explicitly through the new incentive to be a donor. “In the laboratory, we were able to replicate the extensive increase in donations due to the priority rule with other treatments that also lowered the cost of donation by a similar magnitude,” notes Kessler. Current U.S. law prevents the use of payments and rebates for donation outside of the lab, “but changing the allocation of deceased donor organs may be a real possibility.”  

Gaming the System

What do Kessler and Roth expect will be the result of their research? “As additional people study this topic, we hope that it will get more widely discussed in the academic sphere and then in the policy sphere as well. Increasing donation rates either because of the priority rule we write about, or because of some other policy change, would be a great accomplishment,” Kessler says, adding that “we are interested in the mechanisms of the incentives and how they work. We have no direct policy proposition in mind.”

One aspect of their study not discussed in their article are the rules surrounding implementation of a priority program — specifically, how to prevent gaming of the system. “An example of gaming would be if your doctor said to you, ‘You have kidney disease so go register as an organ donor, and tomorrow we will put you on the waiting list.’ That is serious gaming,” says Kessler. “Rules would have to be built in that don’t allow that. Israel, for example, has a three-year waiting period — you only get priority if you have been a registered donor for three years.”

Implementing the rule in an equitable way is also important, Kessler adds. “If some people don’t have access to registering, or aren’t as informed about the change in policy, that could prevent adoption of this kind of approach. We don’t want to penalize people who don’t know what the rules are.”

Already, certain safeguards are in place for many donor transactions: For example, those who receive organs must be healthy enough to benefit from the transplant. Also, in some cases, children who need transplants get priority treatment. And finally, in a move sure to raise ethical issues, a committee reviewing the country’s organ-transplant system is already looking into giving younger, healthier patients waiting for kidneys preference over older, sicker ones.

“But these are not issues that we deal with explicitly,” says Kessler. “What we have noticed, however, is that people who are organ donors seem to be motivated by the good they think the organs will do. So one direction for future research would be to analyze whether giving people certain information — such as how many lives could be improved through the donor registration program — can make a difference in the number of donors.”

Kessler also notes that while major organs like kidneys, livers and hearts are the ones typically associated with transplants, other organs and tissues — including corneas, bone, ligaments, cartilage and tendons — can also be recovered and transplanted.

Cash for Organs

Kessler and Roth describe other approaches besides their own that have been considered as ways to increase organ donation. One is the idea of cash payments for organs, although, as they write in their paper, “proposals to introduce monetary payments for organs are constrained by concerns about the morality and ethicality of such practices.” Consequently, “repugnance towards cash markets for organs limits their feasibility.”

Another proposal that has received a good deal of attention would change the current “opt in” registration method used in the United States to an “opt out” system in which “everyone is presumed to be a donor unless he or she actively indicates otherwise,” says Kessler. A third option, called “mandated choice,” would require everyone — through such procedures as applying for a driver’s license — to specifically indicate whether they wish to be a donor or not.

But Kessler and Roth go on to argue in their paper that “attempts to increase organ donation rates by changing the default organ registration status (and adopting an ‘opt out’ policy) would surely generate more organ donor registrations, since those who do not take any explicit action would automatically be registered as donors. However, such a policy may weaken the link between the registration decision and the legal clarity of the potential donors’ last wishes. Under current United States gift law, changing the default status is likely to have legal consequences that could be detrimental to organ retrieval.”

Singapore, Spain (which has the highest rate of deceased organ recovery) and many other European countries (most of which have lower rates of organ recovery and transplantation than the U.S.) all have an opt-out system.

Looking at broader applications of their research, Kessler and Roth consider the issue of when one can provide incentives to get people to support a public good. “We thought of the pool of registered organ donors as a type of public good,” Kessler says. “In public good settings, you generally cannot exclude people from taking advantage of what is offered. For example, we can’t exclude people from getting the benefits of national security. Another example would be National Public Radio: NPR is a public good because everybody has the opportunity to enjoy it. In public good settings, it is often hard to get individuals to contribute, which is why we tax people.”

What the priority rule does, according to Kessler, is turn a “pseudo public good into something that looks more like a club good. We say that there will be preferential treatment for people who agree to contribute. So for a community swimming pool, there might be special hours for people who pay to help fund the pool. For organ donors, there may be preferential treatment for those who agree to register. To the extent that those incentives provide preferential use of the public good, you can increase contributions.”