Intelligence Inequality and Income Inequality

This article evaluates the relationship between inequality in cognitive test scores across countries and income inequality. By meta-analyzing the standard deviations in PISA results from 2000 to 2018, the authors construct a measure of intelligence inequalities across countries. They then test this measure to investigate if it has any association with income inequality as measured by the gini index. Across all models and subsam-ples, the authors do not find a positive association between intelligence inequality and income inequality. In models where the coefficient is statistically significant, the direc-tion is unexpectedly negative, implying greater intelligence inequality is associated with lower income inequality. This is contrary to theoretical predictions of a positive association between these variables. Finally, the authors also find some evidence that greater mean intelligence is associated with lower levels of income inequality.