Does Marijuana Use Impair Human Capital Formation?

In this paper we examine the relationship between marijuana use and human capital formation by examining performance on standardized tests among a nationally representative sample of youths from the National Education Longitudinal Survey. We find that much of the negative association between cross-sectional measures of marijuana use and cognitive ability appears to be attenuated by individual differences in school attachment and general deviance. However, difference-in-difference estimates examining changes in test scores across 10th and 12th grade reveal that marijuana use remains statistically associated with a 15% reduction in performance on standardized math tests.