The effect of education on cognitive ability

This paper analyzes whether schooling increases intelligence measured by intelligence quotient (IQ). We use a longitudinal dataset where the individuals have conducted IQ tests both at ages 10 and 20. We estimate the effect of schooling on IQ at age 20 conditional on IQ at age 10 and other measures of early cognitive ability to account for selection into noncompulsory schooling. Ordinary least squares estimates indicate that 1 year of schooling increases IQ by 2.9–3.5 points (about 0.2 SD deviations), and instrumental variables estimates are similar.