The Effectiveness of Nudging: A Meta-Analysis of Choice Architecture Interventions
Stephanie Mertens, Mario Herberz, Ulf J. J. Hahnel, Tobias Brosch
Proceedings of the National Academy of Sciences · 2022
Abstract
A broad quantitative synthesis of choice-architecture interventions across domains (health, finance, environment, prosocial behavior), estimating an average effect and mapping which categories of nudge work best.
Methodology
Meta-analysis of more than 200 studies and 400+ effect sizes, classified using Münscher et al.'s taxonomy into decision-information, decision-structure, and decision-assistance interventions.
Findings
Reports a small-to-medium average effect (Cohen's d ≈ 0.43), with decision-structure nudges (defaults, option arrangement) the most effective category and food/health domains especially responsive. The paper's optimistic conclusion was subsequently challenged as inflated by publication bias, making it a key exhibit in the debate over how well nudges really work.
Applied nudge
Prioritize decision-structure changes (defaults, arrangement) over pure information provision, but discount reported averages for likely publication bias when forecasting your own results.
Citation
Mertens, S., Herberz, M., Hahnel, U. J. J., & Brosch, T. (2022). The effectiveness of nudging: A meta-analysis of choice architecture interventions. PNAS, 119(1), e2107346118.
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