An average person born in the United States in the second half of the nineteenth century completed 7 years of schooling and spent 58 hours a week working in the market. By contrast, an average person born at the end of the twentieth century completed 14 years of schooling and spent 40 hours a week working. In the span of 100 years, completed years of schooling doubled and working hours decreased by 30 percent. What explains these trends? We consider a model of human capital and labor supply to quantitatively assess the contribution of exogenous variations in productivity (wage) and life expectancy in accounting for the secular trends in educational attainment and hours of work. We find that the observed increase in wages and life expectancy account for 80 percent of the increase in years of schooling and 88 percent of the reduction in hours of work. Rising wages alone account for 75 percent of the increase in schooling and almost all the decrease in hours in the model, whereas rising life expectancy alone accounts for 25 percent of the increase in schooling and almost none of the decrease in hours of work. In addition, we show that the mechanism emphasized in the model is consistent with other trends at a more disaggregate level such as the reduction in the racial gap in schooling and the decrease in the cross-sectional dispersion in hours.
