I really love the work by William Frey. He’s a demographer at Brookings. He produced a great report on notable trends in the 2020 Census. What really caught my eye was the decline of the number of youth in the United States:

These trends were shocking! For the first time in 30 years, the absolute number of children declined, while the percentage of the population under 18 continued to shrink, from 35% in 1960 to about 22% in 2020. Declining fertility, delayed childbearing, increases in educational attainment, and female labor force participation all contributed to these trends.

With that said, I was initially a little freaked out by these figures. There are few ways to produce adults in a society without first having children be in that society. Frey makes the case more elegantly:

“The 2010-to-2020 loss of over 1 million youths contrasts with gains in that population during the previous two decades. While this is not the first decade to register a loss in the nation’s youth, it is occurring at a time of greater aging of the population. This differs from the situation in the 1960s, when much of the large baby boomer population was under age 18, and comprised 35% of the total population. This youth share dipped over time and has now reached 22%.”

It seems like there are a few aspects to interrogate to determine how concerned I should feel:

The percent of the population under 18.
The inter-decade absolute change in the number of youth.
The relationship between youth share of the total population and the absolute change in youth population.
The association between youth population change and change in the non-youth population.

Let’s situate these in the last century or so to get a sense of how the 2010-2020 change compares to previous changes. I grabbed decennial census data, for total population and under 18 population.

hmmm….we’re seeing a secular decline, with a brief baby boom pause, for the past century+. The anomaly was the high % of kids in the baby boom era, not the decline in recent decades.

OK, what about the absolute change in youth between decades?

Welp…not the first time we’ve seen an absolute decline in the absolute number of children. I suppose if we have two plus census waves of child decline there would be cause for concern. But nothing in recent decades sticks out as a massive shock.

Does the absolute change in # of children do much to affect the percentage of children in the country?

…meh. Not really. There’s just a declining % of children in the country over time. That’s probably more a function of stretching out life expectancy. Absolute change doesn’t really seem to do much. What of the comparison of child population change versus non-child population change?

Nothing too remarkable. It looks like the non-child population can keep climbing regardless of the child fluctuations.

If we look at lagged child population change against non-child population change … there’s not a lot going on. I’m not much of a demographer, so I don’t know the optimal way to assess the link between child population change and non-child population change. But it looks like we’re not seeing any kind of demographic catastrophe driven by child population trends. That’s likely a mixture of immigration and extension of life expectancy.

Overall, it seems like the 2020 Census didn’t tell us anything we couldn’t have predicted from the preceding 10 censuses. I’m not as alarmed as when I first saw Frey’s post. It seems like the US has occasionally had declining child populations, but that hasn’t necessarily resulted in a long-term decline of children or the overall US population. The 2030 census will be informative. But until then, I’m probably not going to spend too many sleepless nights worrying about the trends from the 2020 census.