American Women are Over- (and Under-) Estimating How Many Children They Will Have

(PhysOrg.com) -- Regardless of their level of education, most women in the United States expect to have two children. But women with more education tend to have fewer than two while those with less education tend to have more than two, according to a new study using the most detailed data ever collected on fertility intentions and subsequent fertility behavior.

The two trends balance out for the country as a whole, leaving overall U.S. fertility levels steady even as millions of American women discover their dreams for childbearing diverging from the reality of their lives, says Duke University sociologist S. Philip Morgan, author of an article detailing the study in the March 2010 edition of Population and Development Review.

“The average woman misses her target by one birth,” says Morgan, the Norb F. Schaefer Professor of International Studies and director of Duke’s Social Science Research Institute. “Women are more likely to miss their target than to hit it, and their level of education is an excellent predictor of whether they will miss the target high or low.”

Morgan and his colleagues studied a sample of 7,367 respondents from the Bureau of Labor Statistics National Longitudinal Survey of Youth, who were asked about their fertility intentions a total of 16 times over a 27-year period (1979-2006).

The researchers found a number of biological and social issues affecting whether a woman achieved her target fertility, such as whether she is married or in school when asked about her childbearing plans. Other factors include the type of job or career she has and how long she expects to postpone having children.

“We found that both women and men who postponed childbearing and married late were much more likely to have fewer births than they intended,” Morgan writes in the paper. Childlessness in the United States is a story about postponement, he says, explaining that people’s lives often unfold in ways that aren’t amenable to childbearing.

Morgan says the U.S. data provide clues to understanding why many of the world’s economically advanced nations, including many countries in Europe, are now experiencing very low fertility rates. In countries where low-fertility is an issue, he says, both women and men need to be realistic about their fertility goals and may need to make changes in their lives if meeting intended fertility targets is important to them.

“In low-fertility countries, women are having far fewer children than intended,” he says. “A major part of the explanation is the disjunction between fertility intentions and behavior.”