Meta‑analysis Questions Nudge Effectiveness

Recent syntheses and unpublished nudge‑unit datasets (covering millions of cases in the UK and US) show much smaller effects than published studies and, after correcting for publication bias, possibly no average effect. Some nudges (defaults, tailored interventions) still work in specific contexts, but the evidence calls for shifting from one‑size‑fits‑all nudges to moderator‑aware and personalized designs. — If governments and international organizations rely on nudges as a low‑cost policy lever, weaker-than‑claimed effects undermine those programs and require rethinking evidence standards, transparency, and accountability.