The United States currently has an “opt-in” system for organ donations from the deceased: People must explicitly choose postmortem donation ahead of time (as when they obtain their driver’s licenses). Many other nations have “opt-out” systems: A desire to donate postmortem is presumed to exist unless an individual explicitly chooses ahead of time not to permit donation. How—if at all—would a shift to an opt-out system likely change the supply of cadaveric (postmortem) donations?