The most incisive guide to issues facing the American family today . . . An invaluable resource for anyone wishing to stay on the cutting edge of research on family trends.

-W. Bradford Wilcox
Associate Professor of Sociology, University of Virginia 

Silent Wedding Bells, Half-Empty Maternity Wards

Bryce J. Christensen and Nicole M. King

Economists and policymakers worry about U.S. fertility rates falling to all-time lows. But can America remedy this alarming birth dearth without reversing the downward trend in marriage rates in recent decades? Some progressive social theorists think we can. They point to the growing number of children born to cohabiting couples, and they reason that as cohabitation grows more common and more socially acceptable, it will increasing serve as the functional equivalent of wedlock. Childbearing among such couples will accordingly increase, raising the country’s overall fertility rate. But before policymakers conclude that the birth dearth is as good as over, they should examine a new study showing that while first births are indeed up sharply among cohabiting couples, second births are not. And a nation of one-child couples is a nation on the fast track to demographic winter.

Conducted by demographer Brienna Perelli-Harris of the University of Southampton, this new study compares fertility patterns for married couples with those of cohabiting couples in the United States and Europe. Perelli-Harris bases her analysis on retrospective survey data collected in America and fourteen European countries: the United Kingdom, France, Spain, Austria, Belgium, Bulgaria, Estonia, France, Italy, Lithuania, Norway, Poland, Romania, and Russia. These data do indeed reveal a marked increase in births among cohabiting couples in the United States and across Europe. Perelli-Harris thus remarks that “cohabitation is becoming more common as a setting for childbearing.” 

But when Perelli-Harris looks more closely, she concludes that the surge in births among cohabiting couples is overwhelming in first births. For the United States and eleven of the fourteen European countries, the data indicate that “cohabiting mothers with one child have significantly lower second conception risks than married mothers with one child.” Perelli-Harris remarks that “for these countries, the results are remarkably consistent, with cohabitors having between 40% and 50% lower second conception risks than married women, even when controlling for duration of union before first birth.” The analysis indicates that the gap in rates for second conceptions remains “robust” even when the statistical model takes into account the significantly higher incidence of “union disruption” found among cohabiting couples.

Perelli-Harris labels the “consistent difference between married and cohabiting women across countries” in second conceptions as “striking.” She even frankly concedes that her results run “counter to expectations for Norway and France, where cohabiting and married women were expected to have similar second-conception risks.”

The data allow for only one plausible interpretation: “with respect to childbearing, cohabiting women are different from married women.” And this difference means that “although marriage and cohabitation may become slightly more similar early in the diffusion process, as first births in cohabitation become more normative, cohabitation will not replace marriage as a setting for additional childbearing.”

Because “childbearing within cohabitation has been one of the fundamental indicators of whether a relationship has become more marriage-like,” Perelli-Harris must inform her colleagues that “cohabitation should not be considered ‘an alternative to marriage’ or ‘indistinguishable from marriage.’”

Indeed, Perelli-Harris interprets her own findings in the context of previous studies finding that “cohabitors and married people are quite different,” with cohabitors evincing decidedly “less traditional family-oriented attitudes” than married people.

Sober commentators have every reason to fear the long-term consequences of the American retreat from childbearing. And they have no reason at all to hope that the rise in cohabitation will alleviate those consequences. Quite the contrary.

(Brienna Perelli-Harris, “How Similar Are Cohabiting and Married Parents?  Second Conception Risks by Union Type in the United States and Across Europe,” European Journal of Population 30.4[2014]: 437-64.)