I investigate the extent to which negative alcohol use coefficients in Grade Point Average regressions reflect unobserved heterogeneity rather than direct effects of drinking, using 2001 and 2003 Youth Risk Behaviour Survey data on high school students. Results illustrate that omitted factors are quite important. Drinking coefficient magnitudes fall substantially in regressions that control for risk and time preference, mental health, self-esteem and consumption of other addictive substances. Moreover, the impact of binge drinking is negligible for students who are less risk averse, heavily discount the future or use other drugs. However, effects that remain significant after accounting for unobserved heterogeneity and are relatively large for risk averse, future-oriented and drug-free students suggest that binge drinking might slightly worsen academic performance. Consistent with this, the relationship between grades and drinking without binging is small and insignificant on the extensive margin and positive on the intensive margin.