Childlessness in the US

Recent news on the fertility front in the US has included the fact that the birth rate seems to have stopped its recent decline, and the speculation that there might even be a baby boom on the horizon. Into this mix of ideas is a paper just published by Sarah Hayford in the journal Demography, trying to understand the factors underlying the increase in childlessness in the US (the applied manifestation of which is the increase in child-free zones in the US). In particular, she is interested in knowing how much the dramatic increase in education among women may have contributed to that increase in childlessness. I won't leave you in suspense. Using data over several decades from the Current Population Survey, she finds that increasing education contributes only very modestly to childlessness. Late marriage (after age 40) among women is much more important, despite the fact that there has been an increase in the likelihood of unmarried women having a child. This latter fact gets a lot of publicity, but she argues that childlessness among women who have postponed marriage is really a bigger deal. However, the single most important cause of childlessness is what Hayford calls "secular trends." 

Members of a birth cohort make decisions about childbearing and family formation in response to shared social and economic conditions. Dramatic changes in the social environment faced by cohorts over the late twentieth century, as well as changes in the composition of cohorts of U.S. women, have the potential to explain long-term trends in childlessness in the United States.

In other words, women do not make decisions about marriage and childbearing in a vacuum. They are responding to social cues all around them. On that note, one of the most important points she makes in the article, at least in my opinion, is relegated to a footnote:

Postponement is, of course, mechanically linked to childlessness: women who have an early birth cannot then be childless, and childless women are those who have avoided having children first at young ages and then at successively older ages. Research also suggests that intentions to be childless are rare at young ages, and most permanently childless women reach terminal childlessness by repeatedly postponing the first birth.

This is a key point--few women start out with a preference for no children--they arrive at the situation of childlessness a step at a time as they pursue the increasingly wide range of options open to them in modern western society.