Want a Larger Family? Better Stay in School

Despite spending more time working than any other group, women with advanced university degrees are having more children than other college-educated women. Why? Because the growing divide between the rich and the poor has created a willing pool of mommy-substitutes that the wealthy can afford.

It is fairly well known that fertility rates in the West have been falling for over 200 years. In 1800, for example, the average American woman gave birth to seven children. That rate fell every decade of the 19th century, reaching its current low level of two children per woman by the 1930s. The baby-boom increased fertility temporarily mid-century, when the biggest change came from an increase in the number of women who went from having no children to having at least one. Fertility rates have been in decline fairly consistently since that time.

Part of the explanation for this trend in declining fertility is that as education has become more important in the workforce, families have traded child quantity for child quality – fewer, better educated children are preferred when brains are more important than brawn in generating income.

Starting at the beginning of the 19th century women began taking advantage of this trend (i.e. becoming better educated and spending more time at work and less time at home) and ever since that point family sizes have been tied to the education levels of mothers. Educated women not only lose more income in the time they take away from work to have their children, but work disruptions reduce the future earning potential of educated women by more than less educated women. Add to that the fact that, in general, highly educated parents want to produce highly educated children – which is costly – and we have come to expect that the more educated the woman, the fewer children she will have.  

New research, though, suggests that this is not entirely true. The authors of this study find there is a U-shaped relationship between a woman’s education and her total lifetime fertility. The women having the least number of children are those that started college but did not finish (1.79 on average). The next lowest group is women who have a college degree (1.93). And among women with education greater than high school, the ones with the most children are those with advanced college degrees (1.98).

If you think these fertility rate differences are small then consider this: These numbers include women who have exactly 0 children. The US Census Bureau finds the share of women who have not had a single child before the age of 40-44 increases from 18% for women with some college education to 22.5% for women with an advanced degree. If this is the case, then the differences in fertility rates by education for women who choose to become mothers (as opposed to those who do not) are actually greater than they appear.

What is the explanation for why woman with more education are now having more children despite also spending more time out of the home and in the workforce? Inequality in the US has been growing over the past thirty years with the real wages of workers in the bottom the income distribution falling by 30% since the mid-1970’s by some estimates. This fall in wages of unskilled workers combined with an increase in the wages paid to the highly educate has meant that women with more education can now afford to buy on the market the services that other mothers (and presumably fathers) have to supply themselves.

Housekeepers and nannies are taking educated mother’s place in the home not only allowing her to spend more time at work but also to have more children.

Evidence that inequality can explain why more educated women have more children can be found by comparing the experience of mothers in Western Europe (where incomes are much more equal) with that of mothers in the US. Women in European Union countries have far few children than women in the US – on average one-half child per woman. The authors of this paper argue that the international difference in fertility rates can be explained by low levels of inequality that prevent European woman from substituting their services for those that can be bought on the market. European women spend on average 10 hours a week more on housework than do American woman and 8 hours less in the labor force – despite only having 1.6 children on average.

When I think about the women I know, most of whom have advanced degrees, they really fall into two camps – women with no children and women with 2 or 3 children. The women with no children work long hours. The women I know with children, particularly those who have 3, take advantage of their high education levels to earn a high income but they also tend to have educated spouses that contribute significantly to child care and housework. This paper controls for fathers work hours, but it cannot control for the amount of a man’s non-work hours he spends taking care of his family. If educated women are in a better position to negotiate with their husbands and, as a result, those men are taking more responsibility for children in his non-work hours then this could explain why these woman have more children, independent of their ability to buy  services on the market.

One more thought, is this phenomena of well educate women having more children good for economic growth? If human capital matters (it does) then it should be very good for long-run growth. Especially if women don’t feel they face a trade-off between having children and having an education. This is one more aspect to consider in the on-going debate on how inequality will affect us all in the long-run.

Reference: Moshe Hazan and Hosny Zoabi (2011). “Do Highly Educated Women Choose Smaller Families?” CEPR Discussion Paper No. DP8590.