Inequality and Growth: Why Differential Fertility Matters
We argue that inequality and growth are linked through differential fertility and the accumulation of human capital. We build an overlapping-generations model in which dynasties differ in their initial endowment with human capital. Growth, the income distribution, and fertility are endogenous. Due to a quantity-quality tradeoff, families with less human capital decide to have more children and invest less in education. When initial inequality is high, large fertility dif-ferentials lower the growth rate of average human capital, since poor families who invest little in education make up a large fraction of the population in the next generation. A calibrated model shows that this fertility-differential effect is quantitatively important. We also provide empirical evidence to confirm the links between inequality, differential fertility and growth suggested by the model.