Endogenous Mortality and the Quantity and Quality of Children

Javier A Birchenall, University of California, Santa Barbara

This paper examines the effect of endogenous mortality and parental care on the well-known quantity-quality model of population growth. We associate child quality to nutrition and other parental investments targeted to lower mortality. We show that, due to the quantity-quality trade-off, parents in poor countries have large incentives in favor of more births as changes to the average quality of children represents an expense that has to be applied to a large number of births. As income increases, the incentive for child quality raises so parents asymptotically prefer investments in child quality at the expense of a fixed number of births. In between, we observe an inverse U-shape relation between income and population growth characteristic of all demographic transitions. We test the trade-off with the use of twins as an instrument for unexpected increases in family size. To obtain a sufficiently large and representative data, we combine demographic and health surveys in 37 less developed countries.