Nudge theory

Nudge theory is a concept in behavioral economics, decision making, behavioral policy, social psychology, consumer behavior, and related behavioral sciences^[1][2][3][4] that proposes adaptive designs of the decision environment (choice architecture) as ways to influence the behavior and decision-making of groups or individuals. Nudging contrasts with other ways to achieve compliance, such as education, legislation or enforcement.^[5]

The nudge concept was popularized in the 2008 book Nudge: Improving Decisions About Health, Wealth, and Happiness, by behavioral economist Richard Thaler and legal scholar Cass Sunstein, two American scholars at the University of Chicago. It has influenced British and American politicians. Several nudge units exist around the world at the national level (UK, Germany, Japan, and others) as well as at the international level (e.g. World Bank, UN, and the European Commission).^[6] It is disputed whether "nudge theory" is a recent novel development in behavioral economics or merely a new term for one of many methods for influencing behavior.^[1][7]

There have been some controversies regarding effectiveness of nudges. Maier et al. wrote that, after correcting the publication bias found by Mertens et al. (2021), there is no evidence that nudging would have any effect.^[8] "Nudging" is an umbrella term referring to many techniques, and skeptics believe some nudges (e.g. default effect) can be highly effective while others have little to no effect, and call for future work that shift away from investigating average effects but focus on moderators instead.^[9] A meta analysis of all unpublished nudging studies carried by nudge units with over 23 million individuals in the United Kingdom and United States found support for many nudges, but with substantially weaker effects than effects found in published studies.^[10] Moreover, some researchers criticized the "one-nudge-for-all" approach and advocated for more studies and implementations of personalized nudging (based on individual differences), which appear to be substantially more effective, with a more robust and consistent evidence base.^[11][12]