The sign applies to migrants, apparently.

How Migration Changed in 2015

Evidence from the 2015 County Population Estimates

You know it’s springtime, because the Census Bureau has released its county population estimates, with components of change. Jed Kolko has done a great summary of these estimates, especially showing how the “urban inversion” continues to fade, with suburbs reclaiming their demographic pre-eminence. Here’s his chart:

Source. Read it, seriously.

So, yeah, city centers aren’t at their early-2000s lows, but they’re well off their recession-era highs. And insofar as they remain high, it’s not because they’re beating the suburbs, but because cities are enjoying historically low population growth in more small-town and rural areas, as well as the least dense suburbs.

He also points to regional trends, with stronger performance in the South and West. But the really interesting chart is a bit wonkier. He shows that, on average, what’s really happening is a national return to the average growth rates seen from 1980–2000. Here’s the graph:


That’s pretty interesting. It suggests that maybe we did have some weird demographic/migration activity destabilizing growth from 2006–2011 or so, but that we’re now returning to “normal.” If that’s the case, then the “urban inversion” I’ve discussed should properly be seen as anomalous, or, perhaps too colloquially, a “bubble.” In policy terms, that means urban planners need to, well, plan: for a very near future where current growth rates subside and previous struggles return.

But regular readers will recall I’m not a fan of big aggregates. The charts above are interesting and informative… but what happens when we break the data down into tinier bits?

County-Level Migration Estimates

I Spy Kinda-Sorta Regions, But Not Too Much

The above maps show Census’ most recent estimates of net domestic migration rates in 2011 and 2015. I include both because it’s worth noting, when Census releases new PEP estimates, they don’t just revise that year, they revise back years to the most recent Census. So the 2015 estimates can present different 2011 numbers than the 2014 or 2013 estimates did.

But more importantly, I wanted to highlight a remarkable trend. The 2011 map, on the left, is muddled by lots of patches of different colors. Sure, we can see some strong patches in North Dakota, Florida, Virginia, south-central Texas; and some weak patches in Mississippi and Georgia, southern Idaho… but the dominant impression is of variation. Looking at the 2011 map of migration, a reasonable person would tend to resist regionalist explanations of migration.

Now look at the 2015 map. That’s a different world. There are huge blocks of Texas, Florida, the mid-South, and the Pacific Northwest were every county has positive migration. Meanwhile, negative areas seem to have sharpened as well: in southern Appalachia, upstate New York, Mississippi/Arkansas, there seems to be a hardening of outflow patterns. Domestic migration in 2015 looks much more regionally correlated than in 2011.

This could reflect the same kind of “return to the mean” that Kolko finds. Maybe the recessionary period was a weird time where regional inertia could be broken up or resisted. Maybe the uneven impact of the recession caused local amenities and costs to matter more. Maybe the recovery has been highly regionally localized, in a way the recession was less so. It’s not clear what exactly is going on, but it does seem that regionalized migration is making a comeback. We’ll see if it sticks.

It should also be noted that areas of great migratory diversity still exist. Throughout the west, the plains, the upper south, and along many regional borders, areas of great local migratory differences persist. So there may be meaningful regionalist explanations for some areas, like Texas, but not for others, like Missouri.

Migration, It Is A-Changin’

Maybe Just Changing Back to 2000s Norms

The two maps above show changes in net migration. The left map shows changes from 2014 to 2015, the right map shows changes from the 2010–2012 average to the 2013–2015 average.

The left map does not evince many obvious regional trends. If you tilt your head and squint, you might see some improvement running through Colorado and New Mexic, an area in Texas, a bloc in the Pacific Northwest, and in Florida, but there are many interruptions, and its not clear these are all meaningful units. Certainly no area seems to have a regionally-shared worsening of migration.

On the other hand, longer-term changes from 2010–2012 to 2013–2015 seem to show some strong regional patterns. Both southeast and west Texas have seen separate and robust growth. Fracking, of course, accounts for west Texas. I’m not sure it accounts for east Texan growth, however. Meanwhile, Florida is basically one big bloc of growth. The recession hit Florida extremely hard: it makes sense it would now see serious recovery. There’s also an extended bloc of improvement in the mid-South cities around Nashville, Atlanta, and North Carolina. Finally, there seems to be a persistent improvement from Silicon Valley to Seattle.

Meanwhile, some areas have seen worsening migration patterns amidst the economic recovery: southern Appalachia, upstate New York, New Mexico to western Kansas, central Illinois. There remain areas of highly varied performance, where neighboring counties saw offseting changes, of course. But what is striking is that very large segments of the country seem to be seeing regionally correlated migratory performance.

Again, I’m hesitant to ascribe this to any single cause. Nashville’s growth is not Atlanta’s growth, and regional neighbors, if anything, are natural competitors, not natural co-growers. So we should not assume that a regional correlation in migration means a shared cause of improving (or worsening) migration, but such regional patterns are certainly suggestive. And in some cases, like west Texas, it seems obvious there is basically one factor driving migration throughout the region: oil.

It is notable that, from 2014 to 2015, migration seems to have slowed down significantly in North Dakota and west Texas. Compare the longer-term growth to the annual change: many half-decade big-growers are annual shrinkers. In other words, the slump in oil prices is having a rapidly-felt effect on county- and state-level demographics. From a researcher’s perspective, that’s pretty cool. From a state policymaker’s perspective, that’s really, really scary.


Census 2015 PEP data shows a return to more historically normal migration patterns, including some simplification of regional migration trends. The exact cause of this is not clear, but it’s likely that the recently extreme business cycle is a key driver, alongside various local or regional factors. The strongest growth in migration and population has been in southern and western areas, especially in suburbs. This will undoubtedly come as a frustrating piece of data for many urban enthusiasts. For those of us who’ve been saying the urbanizing trend would soon fade, however, the 2015 PEP data is unsurprising.

See my previous post, how student loans impact urban migration choices.

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I’m a graduate of the George Washington University’s Elliott School with an MA in International Trade and Investment Policy, and an economist at USDA’s Foreign Agricultural Service. I like to learn about migration, the cotton industry, airplanes, trade policy, space, Africa, and faith. I’m married to a kickass Kentucky woman named Ruth.

My posts are not endorsed by and do not in any way represent the opinions of the United States government or any branch, department, agency, or division of it. My writing represents exclusively my own opinions. I did not receive any financial support or remuneration from any party for this research. More’s the pity.

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