Breaking habits: A field experiment with Daan van Soest



We provide evidence of how a temporary incentive for prosocial behavior can kick-start an improved habit. We study habitual behavior within the context of separating waste by households. We conducted a natural field experiment involving 70,000 households in the city of Tilburg, the Netherlands. The incentive consisted of informing households that not separating waste is illegal and punishable by a fine, followed by a four-week intensive and highly salient enforcement campaign. The treatment had an instantaneous, large effect on household behavior. Most of the effect was still apparent many months after enforcement had ended, suggesting a change in households’ habits. Survey responses show that intrinsic motivation dropped immediately after the introduction of the incentive, but that it quickly recovered to its original levels after the incentive was removed. This latter finding does not only stem concerns that the incentive may crowd out intrinsic motivation permanently, but also suggests that the persistence in the behavioral effect is driven by a change in habits and not by a continuing fear for being fined, even after all enforcement has ended. A greater reported use of receptacles, bins and other means that facilitate separating waste also suggests that households are in it for the long run.