THE EFFECT OF EDUCATION ON COGNITIVE
We analyze whether the amount of schooling influences intelligence
as measured by IQ tests. By use of a novel longitudinal dataset we are
able to condition on early cognitive ability to account for selection
into non-compulsory schooling when estimating the effect on cognitive
ability at age 20. OLS estimates indicate that one year of schooling
increases IQ by 2.8–3.5 points (about 0.2 standard deviations).
When family income per family member and teacher evaluations of the individuals
at age 10 are used as instruments for schooling and early cognitive ability,
the return to schooling is estimated to 3.5–3.8 IQ points.