Blech. There has been a spate of news stories (here’s one) claiming that US birth rates have fallen to “the lowest level in at least a century.”

Color me skeptical.

US fertility rates - 1940-2009According to the National Center for Health Statistics (see the chart to the right) child bearing hit its 20th century trough in the mid-1970s, when the “total fertility rate”—the number of children women could expect over a lifetime—dipped down to 1.74. But since then, fertility has inched up. By 2008, the latest year for which we have reliable data, the US fertility rate stood at 2.06 births per woman; and as I read the numbers, even with the 2009 dip, total fertility rates remained well above the lows the nation reached on the trailing edge of the baby boom.

Of course, it’s certainly possible to jigger the numbers to show a “century long low” in childbearing. But you sort of have to cheat to do it.

  • The easiest “cheat” is to measure childbearing as a simple ratio: total babies divided by total population. That way, you include the huge baby boom generation—the youngest of whom are now 46, and well past their peak child-bearing years—in the denominator, which drives down the babies-to-population ratio.

    Yes, that ratio may have reached its lowest level in a century. But adding a bunch of 50-somethings to the calculation doesn’t make today’s 20- and 30-somethings less fertile—it’s mostly a statistical trick, designed to produce a headline.

    The especially odd thing about all this is that as recently as last year, the headlines were trumpeting a surge in childbearing, with more babies born in 2007 than at the height of the original baby boom. That, too, was something of a statistical trick—a headline squeezed out of humdrum data that showed, at most, a modest increase in fertility, coupled with overall population growth.

    None of this would matter much, if the coverage of year-to-year blips and statistical flukes weren’t obscuring a story that, in my mind, is far more important: the alarming share of births resulting from pregnancies that were unintended or unwanted at the time of conception. State and federal studies show that roughly one-third of all births are mistimed, coming earlier than hoped for; and that 5 to 10 percent resulted from pregnancies that weren’t wanted at all. Research shows that births from unwanted pregnancies are associated with worse health, behavioral, and educational outcomes for kids and families. So trimming unintended pregnancies—particularly by improving access to comprehensive reproductive health services—could be a key to boosting the well-being of both families and kids. And incidentally, it would also trim population growth.

    And yet, the data on mistimed and unwanted pregnancies aren’t updated as frequently and reliably as the stories about illusory reproductive booms and busts. The chart above, for example, is from 1999, fer goshsakes. In terms of what we measure, and what we pay attention to, it seems like a case of priorities misplaced, and opportunities missed.