The High and Increasing Fertility of American Billionaires

Felix Roessger, Max Planck Institute for Demographic Research

Economic theories of fertility, although aimed at explaining why fertility seems to fall as income rises, leave open the possibility that beyond some level the effects of income and wealth on fertility will be positive. Most survey data does not allow the study of the very rich, because of non-response and the top-coding of income. Using a unique source, the lists of the Forbes 400 richest men and women, we study how the fertility of the richest differs from the rest of the population. We find (1) the richest Americans have more children than average, and that this difference has growing in recent decades (2) consistent with theoretical expectations, those who inherit their wealth have more children that those "self-made" billionaires (3) and,also consistent with theoretical expectations, billionaire men have higher fertility than billionaire women. The behavior of the extremely rich sheds light on general theories of fertility behavior.