David Lam (Population Studies Center, University of Michigan), Leticia Marteleto (Population Studies Center, University of Michigan)
12/01/2008, at noon in room 6050 ISR-Thompson.
This paper analyzes the links between declines in the family size of women and declines in the family size of children during the demographic transition. We extend Sam Preston’s classic 1976 paper on the relationship between women’s family size and children’s family size in two ways. First, we derive the relationship between the variance of women’s family size and children’s family size. Second, we analyze family size from the perspective of children of a given age rather than women of a given age. We show that the mean family size of school-aged children can be approximated by a simple function of the mean and coefficient of variation of fertility for women born 15-40 years earlier. Applying the framework to micro-census data, we show that mean family size for children is a surprisingly constant multiple – around 1.2 to 1.6 – of the mean family size of women across a wide range of countries and time periods. In contrast with Preston’s predictions that family size of children would fall more slowly than fertility during the demographic transition, we find that the mean family size of children falls at roughly the same rate as the mean family size of women for almost all countries we consider.