The Impact of Poor Health on Education: New Evidence Using Genetic Markers∗

This paper examines the influence of health conditions on academic performance during adolescence. To account for the endogeneity of health outcomes and their interactions with risky behaviors we exploit natural variation within a set of genetic markers across individuals. We present strong evidence that these genetic markers serve as valid instruments with good statistical properties for ADHD, depression and obesity. They help to reveal a new dynamism from poor health to lower academic achievement with substantial heterogeneity in their impacts across genders. Our investigation further exposes the considerable challenges in identifying health impacts due to the prevalence of comorbid health conditions and endogenous health behaviors with clear implications for the health economics literature. ∗We are grateful to seminar participants at the 2005 NBER Summer Institute, 2006 Society of Labor Economics Annual Meeting, 2006 American Society of Health Economists Meeting, 2006 Canadian Economics Association meeting, 3rd Economics and Human Biology Conference, 2006 TARGET Conference at University of British Columbia, University of Toronto, University of Illinois Chicago, Fudan University, Shanghai University of Finance and Economics and BU/Harvard/MIT Health Economics seminar for helpful comments and suggestions. We would also like to thank Paul Wileyto for answering our numerous questions about the data employed in the study. Lehrer wishes to thank SSHRC for research support. Rosenquist wishes to thank AHRQ for support. We are responsible for all errors.