Nationally and globally, demand for organ transplants outstrips supply. In the United States last year, 19,267 donors made a record-setting 39,718 transplants possible, but nearly 109,000 Americans still remain on the organ transplant waiting list.

Cass Sunstein ’78, Robert Walmsley University Professor and former Administrator of the White House Office of Information and Regulatory Affairs in the Obama administration, believes “Nudge theory” might help bridge this gap between supply and demand.

Sunstein joined scholars and leaders in transplant services on Friday, Nov. 6 to discuss strategies to boost rates of organ donation at “Nudging Organ Donation: Tools to Encourage Organ Availability,” an event hosted by the Petrie-Flom Center for Health Law Policy, Biotechnology, and Bioethics at Harvard Law School.

Nudge theory entails gently pushing individuals in the direction of a desired outcome via indirect means. Various considerations go into shaping nudges—in the case of organ donation, Sunstein highlighted two key criteria: saving lives and protecting individual autonomy.

Panelists discussed these criteria as they applied to various international organ donation regimes. Phil Walton, project lead for Deemed Consent Legislation for the National Health Service’s Blood and Transplant Division, highlighted the experience of England and Wales. Alexandra Glazier, president and CEO of New England Donor Services, the nonprofit organization responsible for organ donation for in the region, and a member of the board of directors for the Organ Procurement and Transplant Network that oversees transplantation nationwide, discussed the U.S. experience.

On its face, an opt-out system of organ donor registration might seem to have the greatest potential to save lives. Individuals are registered as organ donors as a matter of course; they must choose otherwise if they would prefer not to donate their organs after they die. However, Sunstein said, the data is unclear as to whether opt-out systems yield more robust results in practice, citing the Netherlands as an example. Moreover, such a regime, he said, might fail to uphold the autonomy of individuals who, due to inattention, become organ donors despite their wishes otherwise.

But recent experiences with the opt-out system in Wales and England point to the viability of the model, explained Walton. He has worked over the past few years to implement this opt-out, “deemed consent” system, by which all adults who lived in England or Wales for at least 12 months prior to their death are considered organ donors (individuals may indicate a choice otherwise).

However, Walton explained, families are still consulted after a patient dies as to whether they consent to donating the individual’s organs. Walton cited evidence to suggest a statistically significant increase in this consent rate in Wales following the implementation of the legislation.

On the other side of the spectrum, an opt-in system, Sunstein explained, seems as though it might not save the most lives—individuals must register to become organ donors. And, while it seems to respect individual autonomy, it fails members of the population that might want to become organ donors but are not aware of the nature of the system.

Glazier suggested that, as it is implemented in the United States, the opt-in system has nearly unrivaled success rates.

She explained that the U.S. opt-in system is second only to Spain in terms of deceased donor transplant rates. Nearly 55% of the adult population in the U.S. has opted into the system, she added.

A switch to an opt-out system might not yield such robust results, especially considering the particulars of American culture. Glazier cited the controversy over mask mandates in response to the COVID-19 pandemic as evidence that the culture in the U.S. is better aligned with an opt-in system than one that appears to be less oriented toward individual choice.

“Since 2012, there has been a 46% increase in deceased organ donors in the U.S.,” Glazier said. “We also recognize that the urgency is there, that more still needs to be done, and this isn’t a system that’s broken, but it’s one that we want to continually optimize.”

Moderator James Lytle, a fellow at the Harvard Advanced Leadership Initiative and Advisor to the Petrie-Flom Center, agreed: “Organ transplantation remains a critical issue for the United States,” he said. “The waiting list grows by one person every 10 minutes, and it’s diminished by the death of 8,000 people every year who didn’t get the organ that their lives depended on. Anything that might nudge an increase in organ donation will save lives.”

Sunstein concluded that both opt-out and opt-in systems hold promise for boosting rates of organ donation. “The difference between opt-in and opt-out is less stark than it might seem. They tend to coalesce if implementation details are done right,” Sunstein summarized. “I think we have paths forward for both opt-in and opt-out regimes.”

Students at Harvard Law School will continue to mull these paths forward, and Friday’s conversation, in the weeks and months to come, said Petrie-Flom Center Faculty Director I. Glenn Cohen ’03: “I’ll probably assign it for homework in a class I teach next semester.”