The organ shortage in the U.S. is primarily due to default rules that require organ donors to formally register their wish to be a donor, known as explicit consent. In surveys, most Americans express a strong willingness to donate their organs upon death, but very few take the costly step of formally registering to become a donor. We tend to take people at their word that they do want to be an organ donor, and advocate switching the default rule from explicit to implicit consent, in which the minority of Americans (15-25 percent depending on polls) who do not want to be donors would fill out a form expressing those wishes.
The state of Illinois has implemented a successful online nudge through its Donate Life Illinois program. The web site attempts to use social norms and influences to convince people to sign up as donors.
Addendum: Reason Magazine’s Kerry Howley points out some complications with the presumed consent policy.
Addendum 2: Britain’s prime minister Gordon Brown backs presumed consent laws for organ donations.