Medical Progress, Fertility, and Women’s Work in the Twentieth Century

We first build a theoretical model where improvements in maternal health determine a decline in the cost of having children and reduce women's comparative advantage in home activities. Medical progress has two opposite effects on fertility: a positive direct effect that arises from the reduction in the cost of children and a negative indirect effect stemming from the rise in women’s incentive to invest in market skills. The model endogenously generates the rise in fertility and women’s participation starting in the late 1930s, as well as the decline in fertility and the continued rise in participation from the 1970s on. We then quantify the effect of medical progress on women’s fertility, human capital investment and labor force participation. Our empirical strategy is to use the decline in maternal mortality between 1935 and 1955 as a summary measure of medical progress. We exploit geographical variation in the timing and intensity of this decline to gauge its impact on different cohorts of women at varying points of the life-cycle. We find a very large effect of medical progress on the fertility of women who were affected by the shock. At each point of these women’s life-cycle, a 1% difference in maternal mortality decline across two states translates into a 1% higher fertility in the state that experienced the larger drop.