The U.S. Has Had Stable Replacement Fertility for Forty Years

Another dispatch from the Schreyer Seminar on Marriage, Family, and Social Sciences

So argues Philip Morgan, an eminent Duke sociologist.

He says that the big decline in fertility has come from the disappearance of the third and fourth children that parents had during the Baby Boomer. There has not been a huge increase in women having no children at all in this country.

There is also the appearance of a decline in fertility because women have been delaying having their first child by about a year per decade. This means that fertility so far of women in their twenties is much lower than it used to be. However, most women will have those delayed kids, eventually.

The United States also benefits from the somewhat higher fertility of immigrants, especially from Mexico and points south. This higher fertility only lasts a generation, and will probably decline as the fertility of the sending countries goes down. Morgan estimates that higher Hispanic fertility accounts for about 9% of total U.S. fertility.

These elements - most women eventually have a couple of kids, and some women have more - has, Morgan argued, actually kept U.S. fertility at about a steady replacement level of 2.1 children per women for more than a generation. Moreover, he believes, we can keep this level of fertility steady, to produce long-term population stability. This would be a new thing in the history of America. Morgan believes it would be a good thing.