Default rules, ethical reminders, and registration costs: An experiment on stem-cell donor registration

Although the experimental economics literature provides strong evidence on the effects of default choices on the rate of individuals willing to donate their organs post-mortem, the real-world evidence on these nudges is less clear. We conduct a set of online experiments to analyze the difference between hypothetical and real-world decisions for stem-cell donor registration. Stem cell transplants are a last-resort treatment option for patients with leukemia and lymphoma. These transplants require donations that fit the patients HLA type and similarly to post-mortem organ donations, demand for transplants is higher than supply. Our experiment consists of two stages. First, participants play an interactive decision game on stem-cell donation similar to what has been used in the organ transplantation experiments. Second, we give participants the option to sign up for an actual stem-cell donor registry. We use different choice-defaults and information treatments in both stages. 309 subjects participated in the experiment from March to September 2022. Most treatment nudges had small and mainly insignificant effects on hypothetical or actual registration decisions. Our strongest intervention however, sending registration kits directly to participants homes did clearly increase registration rates.

(Authors: Helene Könnecke, Simon Reif, Harald Tauchmann, Daniel Wiesen)