Queen’s University

The causal effect of health on education outcomes remains an open question in economics since unobserved factors may explain the correlation between health and education. Using a very rich data set that tracks 900 students through high school and an instrumental vari-ables strategy we estimate the causal impact of obesity, ADHD and depression on adolescent academic performance by exploiting variation in genetic markers. Our data contains direct genetic measures of the DRD2, DAT and CYP2B6 loci, which are well known in the scientific literature to affect the health outcomes, considered in our study. Further, we account for the endogeneity of smoking which may serve as an antidepressant and appetite suppressor. We present evidence that these genetic markers and their interactions are valid instruments with good statistical properties. Second, we find there is substantial heterogeneity in the effects of health on academic performance. The academic performance of female students is strongly negatively affected by poor physical and mental health outcomes