Nudging: Progress to date and future directions.

Nudges influence behavior by changing the environment in which decisions are made, without restricting the menu of options and without altering financial incentives. This paper assesses past empirical research on nudging and provides recommendations for future work in this area by discussing examples of successful and unsuccessful nudges and by analyzing 174 articles that estimate nudge treatment effects. Researchers in disciplines spanning the behavioral sciences, using varied data sources, have documented that many different types of nudges succeed in changing behavior in a wide range of domains. Nudges that automate some aspect of the decision-making process have an average effect size, measured by Cohen's d, that is 0.193 larger than that of other nudges. Our analyses point to the need for future research to pay greater attention to (1) determining which types of nudges tend to be most impactful; (2) using field and laboratory research approaches as complementary methods; (3) measuring long-run effects of nudges; (4) considering effects of nudges on non-targeted outcomes; and (5) examining interaction effects among nudges and other interventions.