We document a robust negative relationship between the log of mean annual hours in an occupation and the standard deviation of log annual hours within that occupation. We develop a unified model of occupational choice and labor supply that features heterogeneity across occupations in the return to working additional hours and show that it can match the key features of the data both qualitatively and quantitatively. We use the model to shed light on gender differences in labor market outcomes that arise because of gender asymmetries in home production responsibilities. Our model generates large gender gaps in hours of work, occupational choices, and wages. In particular, an exogenous difference in time devoted to home production of ten hours per week increases the observed gender wage gap by roughly eleven percentage points and decreases the share of females in high hours occupations by fourteen percentage points. The implied misallocation of talent across occupations has significant aggregate effects on productivity and welfare.