Behavioural nudges, such as defaults, improve human welfare by reducing choice overload. But how far should policy-makers go in reducing available choices? Using a preregistered, online survey experiment, we randomly assign 1,518 UK citizens to two versions of the same opt-out default nudge aimed at encouraging charitable donations. In one version, the default was embedded in a list of multiple options, whereas in the other it was presented as a single choice. In both versions, participants could opt-out and choose any preferred donation amount. We find that when the default is embedded in a multiple-choice list, opting out rates and average individual donations are significantly higher compared to the standard single-choice default. Our findings suggest that encouraging active choosing alongside a default can improve agency without necessarily deteriorating behavioural outcomes.
