Falling U.S. fertility rates have been making headlines.
These reports tend to focus on a single measure: the average number of children that women have, nationally. However, this one number masks large and interesting variation in people’s childbearing behavior.
The National Survey of Family Growth – one of the best sources of information on this topic – released a report in July that points to some of this variation.
It shows that the number of children and the timing of childbearing differ meaningfully across women and across groups, reflecting some of the significant demographic divides in the U.S.
There’s a lot of variation in family size – but the data show that large families are unusual.
Among women who have recently completed their childbearing, the most common number of children in the national survey was two, followed by three and then one, and then none. Large families are the least common: Only 13 percent of women have four of more children during their lives.
By historical standards, the current dominance of the two-child family is notable. Before now, societies had not converged around a particular number of children to such a large extent. And yet, only about one-third of women have two children – so the majority don’t conform to this standard.
Women may start reporting fewer children on average in upcoming years, as generations who were hit hardest by the Great Recession finish out their childbearing years.
There are also interesting differences by gender. Men were more likely to report lower numbers of children compared to women. This is likely due to men not reporting some children they fathered, particularly those fathered at younger ages.
The first child
The timing of childbearing differs substantially across groups.