Tag Archives: census

Four Southern Cities

This is way off topic, but back in March when the new Census population estimates came out, I tweeted about slow growth in Alabama and negative growth in Mississippi. I’m wondering why they aren’t part of the “new south”, generally taken to be fast growing Sunbelt cities like Charlotte and Atlanta. Why does Atlanta boom, but Jackson doesn’t? Many of the responses boiled down to “because it’s Mississippi” which is sort of circular logic.

I thought it would be interesting to compare population growth since 1860 in four southern cities: Jackson MS, Birmingham AL, Atlanta GA, and Charlotte NC. Since municipal boundaries in the US are illogical, often changing, and hard to trace, I’m using county level data, comparing the populations, based on the 2015 definitions of the metropolitan statistical area (MSA) for each city.

I also added an “Atlanta Redux” where I threw out the 9 counties (out of 29) in the Atlanta MSA that still, as of 2016, have not reached population 30,000. These counties are way out near the edge of the city and were only recently sprawled into the Atlanta MSA. Their inclusion in the regional population back to 1860 probably unfairly inflates Atlanta’s size at the outset of the Civil War, when counties 40 miles out would not have had much plausible connection to the city but still had some population. I’m including both the full MSA and the reduced version to let readers compare.

fsc-popa

Even the redux version of Atlanta was the biggest city of the four in 1860. Not much divergence is seen between Birmingham, Atlanta, and Charlotte until after World War 2. Jackson appears to have always grown more slowly, though this fate would not have been at all obvious to an observer in 1880, when Jackson was over 50% larger than Birmingham.

Plotting the population on a logarithmic scale can help us see patterns more easily, as the runaway growth of Atlanta makes the others look flat by comparison.

fsc-poploga

Plotted this way, the post-World War 2 growth of Atlanta and Charlotte doesn’t look unusual; it just looks like a continuation of previous trends. Atlanta, especially the redux version, starts growing a little faster than Charlotte after the war.

More interesting is Birmingham, which grew very quickly for decades after the Civil War, going from about 60% of Jackson’s size in 1870 to 120% of it in 1890. Birmingham even passed Charlotte for a few decades, going from 40% of its size in 1870 to larger by 1910. An observer in 1930 might have expected Birmingham to surpass Atlanta in another 10-20 years, especially the redux Atlanta. Jackson, meanwhile, experienced a strong decade from 1870-1880, but never grew very quickly again.

After 1930, Birmingham, which had been the rising star, began to fade, and was surpassed by Charlotte by 1960. So, what happened to Jackson after 1880? And what happened to Birmingham in 1930? I’ve yet to find out.

Another way to look at this data is to look at the amount of growth in the central county (where the main city is located) and compare that to the growth of suburbs. Here’s the breakdown for these four cities, with the central county on the bottom of the graph.

fsc-Jacksonfsc-Birminghamfsc-Charlottefsc-Atlanta

It is interesting that in Birmingham and Jackson, the central county stopped growing when the MSA as a whole started growing more slowly. However, it’s important to not try to read too much into this – did the MSA grow slowly because the central county was being neglected, or did the central county stop growing because there wasn’t much growth to be accommodated anyway?

One unappealing answer is that there is simply a great deal of luck in these outcomes. Obviously it helps for the city to be well run, but there are many factors making a complex result, and sometimes you just get bad luck. This rudimentary look is obviously not enough to tell us much about why these cities grew at different rates, but if anyone has any ideas, I’d love to hear them.

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Census 2016: The Sunbelt Strikes Back

Just some short thoughts for now, perhaps more soon if time permits.

The Census Bureau released its 2016 county population estimates late last week, and the numbers show a reversion to the trends of the 1990s and early 2000s: Sunbelt suburbs are growing faster than legacy cities. Blame land use policies if you like (I sure will) but those are the facts.

If cities are not growing as fast as once thought, though, it hasn’t been to the benefit of rural areas. Small counties were disproportionately represented among counties that lost population. The table below shows the number of counties gaining or losing population by county size.

census2016

Of the 37 counties that had a 3% or greater population loss, 27 had population under 10,000 and 36 had population under 50,000. The only sizeable county to lose 3% or greater was San Juan County, NM, which lost -3.05% of its 2015 population of 118,701 and has lost over 11% of its population since 2010. It is the only county of over 100,000 people to lose anywhere near that much; the next closest was Cambria County, PA, which lost 6%.

Further, of the 456 counties that lost over 1% of their population, 424 had population of 50,000 or less. Only 3 had population over 200,000 (St Louis city, Baltimore city, & Muscogee County GA). Of the 45 counties with population of 1,000,000 or more, only 6 lost population: Cuyahoga OH (Cleveland), Wayne MI (Detroit), Cook IL (Chicago), Suffolk NY (Long Island), Allegheny PA (Pittsburgh), and St Louis MO (St Louis suburbs). Six had population growth over 2% (Mecklenberg NC, Travix TX, Hillsborough FL, Clark NV, Orange FL, and Wake NC).

In short, the census estimates reflect long-standing trends of rapid growth in the Sunbelt and stagnation in the Rust Belt.

It’s a little unfair to compare small counties and very large counties, because it’s easier to have a large percentage swing in a small county. For example, Los Angeles County has over 10 million people, and there are probably some communities of 10,000 therein that shrank. The graph below avoids this problem by showing the distribution of counties gaining and losing population for counties up to 500,000 people. As we can see, the distribution skews towards the negative side for counties with population under 50,000 and toward the positive side for counties with population above 50,000.

census2016-2

For counties with over 1,000,000 people, the fastest growing counties are all in the Sunbelt, dominated by places like NC, FL, TX, and NV. Perhaps the most impressive county was Maricopa AZ (Phoenix) which grew by almost 2% and over 80,000 people. The fastest growing was Wake NC with 2.43%.

In California, the fastest growing big county (population over 250,000) was Placer, in the Sacramento suburbs, with 1.64%. Unlike many counties, growth in Riverside County actually picked up last year, with 35,000 people or 1.48%. Riverside was also the only big county in California to have a large positive contribution from domestic migration. The negative domestic migration from California counties is shocking: more domestic migrants (75,168) left LA County than the two largest domestic migrant gaining counties combined – not coincidentally, Maricopa County with 43,189 and Clark County NV with 27,735.

There will surely be many takes on the meaning of this census data, but the simple take here is that this is just a triumph of people doing what they’re allowed to do. A lot of economic growth in the US is in the Sunbelt, so people are moving there, and they’re moving to suburbs because that’s what you’re allowed to build. As for why growth is in the Sunbelt, that’s a more complicated question. The structural reasons for the decline of rural counties and the continued stagnation of Rust Belt cities are beyond the means of this blog.

However, given California’s high and still-rising cost of housing, our story isn’t very complicated: the economy is pretty good and lots of people want to live here, but we don’t build enough housing to let them do it. High housing costs are hurting California, and the sooner we do something about it, the better.