Beyond Immediate Effects: Durability under Continued Exposure and Post-Treatment Persistence in Behavioral Environmental Interventions

Behavioral environmental interventions are increasingly used as relatively low-cost complements to prices, regulations, and technology-based policies. Their policy value, however, depends not only on their immediate effects but also on how those effects evolve over time. This article reviews long-horizon evidence while distinguishing two empirical objects: durability under continued exposure, or whether effects remain while the relevant intervention continues, and post-treatment persistence, or whether effects survive after the focal treatment is withdrawn. We synthesize field evidence on repeated feedback and social comparison, educational and informational campaigns, commitments and goal-based designs, and defaults and other maintained choice architecture. We then examine how these intervention types may generate durable or persistent effects, using the four pathways proposed by Frey and Rogers (2014) as an interpretive framework. Finally, we review the smaller body of studies that provides empirical leverage on particular interventionpathway combinations. Overall, the reviewed evidence suggests that sustaining effects under continued exposure is generally more attainable than preserving them after treatment withdrawal. Even when effects remain detectable over time, attenuation and backsliding are common. Evidence on the mechanisms through which short-run responses become durable or persistent remains limited. Future research should therefore identify which mechanisms, domains, and policy combinations convert short-run behavioral responses into durable or post-treatment effects. It should also measure long-run spillovers and welfare consequences, so that evaluations capture the broader net policy value of behavioral environmental interventions.