This paper examines faculty time allocation decisions that are fundamental to the functioning of a university. A random-utility approach yields a grouped-data, multinomial legit model and predicts that time allocation decisions depend systematically on both personal and institutional attributes. The empirical results for a random sample of U.S. arts and sciences faculty indicate that structural differences between universities with different research orientations account for most of the significant differences in faculty time allocations. Faculty characteristics reinforce institutional missions, however, and thus condition university policies for change (for example, attempts to mandate greater time to teaching in research universities).