PNAS Nexus Oct 28 2025 Every day, 17 Americans die while waiting for an organ transplant. Opt-out organ donation policies, which enroll everyone into post-mortem donation programs by default unless people choose to opt out, have been touted as a way to increase the supply of desperately needed organs. But opt-out organ donation policies may reduce living organ donations, leaving systems no better supplied with lifesaving organs. Pascal Güntürkün and colleagues analyzed epidemiological data from