Meta-analytical effect of economic inequality on well-being or mental health

Some of us have known this for some time:

Exposure to economic inequality is widely thought to erode subjective well-being and mental health, which carries important societal implications. However, existing studies face reproducibility issues, and theory suggests that inequality only affects individuals in disadvantaged contexts. Here we present a meta-analysis of 168 studies using multilevel data (11,389,871 participants from 38,335 geographical units) identified across 10 bibliographical databases (2000–2022). Contrary to popular narratives, random-effects models showed that individuals in more unequal areas do not report lower subjective well-being (standardized odds ratio (OR_+0.05) = 0.979, 95% confidence interval = 0.951–1.008). Moreover, although inequality initially seemed to undermine mental health, the publication-bias-corrected association was null (OR_+0.05 = 1.019; 0.990–1.049)¹⁷. Meta-analytical effects were smaller than the smallest effect of interest, and specification curve analyses confirmed these results across ≈95% of 768 alternative models. When assessing study quality and certainty of evidence using ROBINS-E and GRADE criteria, ROBINS-E rated 80% of studies at high risk of bias, and GRADE assigned greater certainty to the null effects than to the negative effects. Meta-regressions revealed that the adverse association between inequality and mental health was confined to low-income samples. Moreover, machine-learning analyses¹⁹ indicated that the association with well-being was negative in high-inflation contexts but positive in low-inflation contexts. These moderation effects were replicated using Gallup World Poll data (up to 2 million participants). These findings challenge the view that economic inequality universally harms psychological health and can inform public health policy.

That is now published in Nature, by Nicholas Sommet, et.al., via the excellent Kevin Lewis.