This paper studies the determinants of college major choice using an experimentally generated panel of beliefs, obtained by providing students with information on the true population distribution of various major-specific characteristics. Students logically revise their beliefs in response to the information, and their subjective beliefs about future major choice are associated with beliefs about their own earnings and ability. We estimate a rich model of college major choice using the belief data. While earnings are a significant determinant of major choice, tastes, which are heterogeneous, are the dominant factor in the choice of major. We also investigate gender differences in major choice.