This article measures the effects of college drinking on study hours, grade point average (GPA), and major choice using simultaneous equation models and data from the 1993 College Alcohol Study. Binging and intoxication decrease GPA directly and indirectly by reducing study hours. Greater frequency of drinking increases the effect on study hours but not the total effect on GPA. College drinking increases the probability of choosing a business major but decreases the probability of choosing engineering. Simulations show that the effects of heavy drinking on GPA and major choice reduce future weekly earnings by between 0.3 and 9.8%.