Longevity and Hours over the Lifetime: Data and Implications

Recent growth papers have utilized the Ben-Porath 1967 mechanism according to which prolonging the period in which individuals may receive returns on their investment spurs investment in human capital and cause growth. Implicitly, one implication of these models is that total labor input over the lifetime increases as longevity does. We propose a thought experiment to empirically evaluate the relevancy of this mechanism to the transition from "stagnation" to "growth" of the nowadays developed economies. Specifically, we estimate the expected working hours over the lifetime of ten consecutive cohorts of American men born between 1850 and 1940. Our results show that despite a gain of almost 11 years in the expectations of life at age 20, the expected working hours over the lifetime have declined from more than 125,000 hours to less than 100,000 between the oldest and the youngest cohorts. We conclude that the Ben-Porath mechanism have had a lesser effect than previously thought on the accumulation of human capital during the growth process