National Health Statistics Reports covering births to women in the United States between 2007 and 2017 show the Total Fertility Rate on a level or downward sloping line few babies per woman.

Rural counties report the highest fertility rate, an estimated 1.95 total births per woman, and large metro counties report the lowest: 1.71 total births per woman.

Age of first birth, also a reliable predictor of completed family size (women who start childbearing late tend to have smaller families), varied in 2017 between 24.5 in rural counties, 25.8 in small or medium urban counties, to 27.7 years of age in large metro counties.

A fertility rate below 2.1 total births per woman is less than the number needed just to replace parents. Barring a push from immigration, it entails population decline.

However, this demographic future is unlikely to materialize. The currently thriving economy should be reflected soon in a rising fertility rate. The 2020s baby boom beckons.

The fertility opportunity hypothesis, which I first proposed in 1979, holds that women and couples want and typically have larger families when they perceive expanding economic opportunity. Conversely, potential parents limit family size when economic prospects appear dim. The hypothesis is supported by cross-cultural and historical data. Two opportunities also allowed testing the predictive validity of the hypothesis, with gratifying results.

There are both practical and ethical limits on testing such human behavior, but sometimes sudden political or economic change provides the evidence. This occurred when the economies of nine Asian countries imploded in the summer of 1997. The Thai baht was devalued by 40% percent, and, to varying degrees, all nine countries, then known as the Asian tigers, were affected. Japanese unemployment rates in 1998 and 1999 rose to a level higher than at any time since 1953; personal bankruptcies rose by 50%, and the suicide rate reached the highest on record.

At that time, fertility rates in all nine countries were slowly declining, but I predicted a sharper drop-off, which was later validated at a statistically significant level.

Since the mid-1970s in the United States, the less affluent 80% of the population have labored under income growth that barely kept pace with inflation. Many women entered the labor force to supplement the family income. Only recently have those bottom 80% begun to see real income gains. In this months State of the Union address, President Trump referred to this as a blue-collar boom. Call it what you will, but the increased buying power is reflected in a healthy housing market, driven, reportedly, by millennials, who are squarely in the period of life where people form families.

I predict that the new affluence will manifest itself in childbearing as well. With relevance for the culture, one 30-year-old Tennessean woman remarked that childbearing is the new status symbol."

Further, women watching the biological clock know that their best childbearing years come before age 40. They are probably now in a hurry. This is why the current economic boom will give way to the 2020s baby boom.

The last U.S. Baby Boom spanned between 1947 and 1962, corresponding to a labor market that featured ample job opportunities and fast promotions. The average family size was above three children per woman.

The baby booms underlying causes were an expanding economy paired with a small labor force. Very low fertility rates during the 1930s Depression resulted, one or two decades later, in relatively few entrants into the labor market; the condition was exacerbated by educational alternatives to work afforded through the post-war GI Bill of Rights. The abundance of jobs, combined with the paucity of job-seekers, drove wages and benefits upward and made working conditions better.

The perception of economic opportunity turns people into parents. Steady as she goes, and the current healthy labor market in the United States will lead to enthusiastic family formation and a growing population.

Virginia Deane Abernethy is a professor emeritus at the Vanderbilt University School of Medicine in Nashville, Tenn.

Excerpt from:
Is the American baby boom of the '20s on the way? - Washington Examiner