I was doing what everyone does last week, meandering around the Census Bureau website checking out the various data sets they make available to the general public. While there, I came across something I hadn’t noticed before: a state-level database of people’s ages for each year from 2010 to 2020. I, like everyone, have a favorite Census Bureau data set, and as you no doubt recall from an article I wrote in June 2021, single-year-of-age data are my favorite.
In part that’s because it allows us to do interesting comparisons about generations. Generations are nebulous things (here’s where I quickly note that I wrote a book on the subject) but, if we use Pew Research Center’s definitions, we can get a sense for how age cohorts in the U.S. have surged and waned since 2010 — and where.
I started by just breaking down the population of each state into six buckets: the four most common generations — baby boomers, Gen X, millennials and Gen Z — and then everyone older and younger. There were no “younger” Americans in 2010, based on Pew’s definitions, so you see them emerge only a few years into the process.
The result was this map, showing the gradual shift from old to young in each state over time.
This is admittedly hard to read, however accurate or aesthetically appealing. How does Georgia compare to Florida, for example? It’s hard to say.
So I made the data into line charts. Here, each generation is shown as a percentage of the total population over time. I left off the oldest generational groups largely because I wanted to focus on the contrast between boomers and millennials (with always-overlooked Gen X floating there in light gray, ignored and riddled with angst).
Now we see some differences. We see a lot of states where the purple boomer line is consistently above the black millennial one and several states where those lines intersect. We see, too, that the millennials line for D.C. is off the charts, extending up and out of the bounding box.
I figured that a direct comparison of the two largest generations — the boomers and the millennials — might be worthwhile. I took the annual percentage of the population each represented in each state and compared them. The result? A clear sense of where America is older (the Northeast) and where it is younger (the Southwest).
Again, D.C. stands out, but so does Utah, where the population is much heavily younger than most other states. You can also see the effects of the fracking boom in North Dakota as the population suddenly shifts a lot younger. One thing that the younger states have in common, it’s worth noting, is that they are often much less heavily White.
That the population of millennials is surpassing that of the boomers is not a surprise both for the reason that we all understand how age works and because this has been covered before. A few months ago, in fact, I pointed out that in the general period indicated above, the workforce had gone from more-heavily boomer to more-heavily millennial.
Still, the third chart above shows that shift in a way I hadn’t seen before. This transition, one that’s undergirding a lot of the political and economic tension in the country, is not a uniform one. And the way it’s not uniform itself tells us a lot about those tensions.