The power of active choice: Field experimental evidence on repeated contribution decisions to a carbon offsetting program

Abstract

We investigate how the introduction of an Active Choice requirement influences subject proclivity to contribute to an impure public good in one time and repeated interactions. In a large-scale field experiment, we analyze more than 10000 contribution decisions to a carbon offsetting program in the context of online ticket sales for long-distance buses. We find that the simple requirement of an Active Choice – which circumvents the ethical issues posed by an opt-out design – not only increases participation rates by almost 50% in a first booking decision, but also boosts participation in subsequent bookings. At the same time, the introduction of Active Choice does not induce a substantial decline in returning customer rates. Our data support the theoretical assumption that anticipated guilt is a causal mechanism by which Active Choice induces higher contribution rates, as the opportunity for “choice avoidance” that is inherent to opt-in settings may help subjects circumvent feelings of guilt that would otherwise result from explicit free-riding.