Iowa’s Migration Story
Past, Present, and Policies for the Future
Last week, I spoke at the SMART Economic Development Conference in Des Moines, Iowa, on Iowa’s migration record. I have nothing but good to say about the folks in Iowa and the warm welcome I’ve received every time I’ve visited. For the benefit of conference attendees who want more data and graphs, and for the vast majority of my readers who didn’t get the unparalleled pleasure of hearing me speak (my jokes are great), I’m posting a version of my presentation here.
Why Do We Care About Migration?
I’m always interested to hear the reasons people give for why migration matters (or doesn’t). What I heard in Iowa was similar to anywhere else: concerns over workforce recruitment, “brain drain” and educational retention, and the growth or decline of the population. Moreover, as a nation, we have a powerful migration story embedded in our national identity, from the settlers at Jamestown and Plymouth to the Oregon Trail. We actually have national holidays about migration. So migration in the United States almost has a moral tone to it: places with net inflows are “winning” and places with net outflows are “losing.”
Beyond that, migration is the most volatile and determining component of population growth for localities. While the rate of international migration according to the Census Burea has just a 0.22 correlation with the overall rate of population growth, and natural population growth just a 0.32 correlation, the rate of internal migration has a whopping 0.91 correlation with the rate of population growth at the county level. In terms of raw numbers, the absolute amount of population change driven by internal migration is larger than the other components too: differences in migration led to a net change of 2 million people in various counties in 2014, compared to 1.5 million for natural increase or decrease, and just 1 million for international migration. Internal migration is the largest and the leading component of local population growth or decline.
In other words, we care about migration because migration matters: economically, culturally, politically, and demographically.
Migration Mythology
Vans, Blizzards, and Migrating Money
There’s a lot of dubious data out there on migration. Because it’s such a big factor in local success, there’s no shortage of opinions on the matter, and anybody who’s got information tangentially connected to the issue wants in on the fun. For example, Atlas Van Lines and United Vans publish maps of which states get the most and least van drop-offs and pick-ups, allegedly a proxy for migration.
There are problems with these maps, of course. First of all, individual companies may not be representative: because they have different levels of coverage of the nation, and because they may even pick a market strategy based on perceived migration trends, their data is likely to be skewed.
Beyond that, van rentals may not even be a very good proxy for migration. Many people will migrate without moving vans, either because they have few possessions, sell many of those possessions, or are temporarily separated from “home” for just a year or a few months. Moreover, vans may be rented and used without any migration: there are plenty of reasons beyond migration that can motivate the rental of a truck.
Another common migration story is about money, and specifically how money is leaving some states (New York, Illinois, California) and moving to others (Texas, Florida, Arizona). This story is based on IRS data that tracks relocated tax filers and their associated dependents and AGI. It’s one of the most comprehensive databases out there.
But IRS data doesn’t actually track movement of money. When a person moves from Iowa to Virginia for a job, for example, their old income in Iowa doesn’t move with them: they leave that job, and someone else can take it. IRS data does not link across years and tell us how a person’s income changed through migration, and it misses lots of migrants, like college students who don’t file taxes.
This map purportedly shows the “Snowbelt” and the “Sunbelt.” Aside from the odd color choices (shouldn’t the Snowbelt be white and the Sunbelt be red?), it is problematic for its generalities. Maine and Vermont are rather cold places, but kept electoral college votes, while New Jersey and Missouri Connecticut are substantially warmer, but lost people. Frigid Minnesota did better than comparatively warmer Missouri. Meanwhile, sweltering Louisiana and Mississippi lost people, while rainy and frequently sunless Washington and Oregon gained. So much for weather. Big regional generalizations like these are frequently wrong as they elide crucial nuance and detail.
Migration Mythology
Wanted: Reliable Data
Migration data has many sources: private companies, nonprofits, authors, governmental agencies, the Census, universities, academic research, and others. While some of these sources agree, the reality is that different sources of migration data often provide remarkably different estimates of migration. To make matters worse, many sources of this information, whether van lines hoping for some viral marketing or pundits making a political point, are what we might call highly motivated information providers. There interest is sometimes less in the technical quality of the data and more in a highly desirable interpretation.
Furthermore, all of the data shown above is aggregate data. It’s not broken down by income, or sex, or education, or ethnicity. It’s just a net measure, so you don’t know inflows and outflows, just a balance. This is a problem, as migration varies widely across different groups, and areas with similar net flows may still have hugely different migration patterns.
Finally, state-level data is not necessarily the most useful data. States are fun levels of analysis because there’s tons of data, and the policy choices are still high-stakes enough to merit political and media attention. But in reality, people don’t move to a state. Migrants move to a house on a street in a neighborhood that’s part of a city located inside a county within a region in a given state. “Location” is like a Russian doll: you can always take it one level further down, and how you define your region will determine many of your conclusions.
Migration Mythology
Mythbusting Questions
Facing large amounts of mythology, policymakers need tools to get to the facts. The first thing they can do is ask questions of whoever presents them with data. While there’s no perfect list, these are a few questions I like to ask when I analyze migration for a given region, or when encountering a given “migration” dataset:
- Who are the migrants being measured? If there’s a policy question being debated, do these specific migrants actually matter or relate to that policy question?
- Where are migrants actually going, and how long do they stay there?
- What are out-migrants doing after they leave, or in-migrants doing once they arrive?
- When did these migration flows begin? How do they compare to previous flows? Has anything changed recently?
These questions help lead us to the big one: Why does migration, as presented in a given set of data, look a certain way? Once we have a historical frame of reference, know how a given region like Iowa relates to other regions, know who migrants are, and know what they are doing, we can talk about what’s causing migration. After we do that, there’s a second round of questions to ask:
- Does migration even matter? Fairly frequently, the answer is “No.” Migration simply does not have a meaningful relationship with every policy question or current event, as much as migration and demographic professionals might like.
- What do migrants say matters to them? Is there survey data?
- Are we telling a just-so-story? You know those stories about how the monkey got its tail. Are we making neat-and-tidy migration connections as a way of telling a moral lesson about society, and thereby missing essential details? For a good example of this, see my writing about the alleged revitalization of American inner cities.
- Are we forgetting anything obvious? I have a checklist here when I review migration for a given region: military, colleges, oil, disasters, and huge foreign investment. It’s surprisingly easy to forget these things when we drill into migration but their impact can be genuinely enormous. Always start with the big, obvious shocks when looking for an explanation.
Once we understand more about migrants, and once we’ve asked the above “control questions” to make sure we aren’t being misled by obviously faulty or ignorant reasoning, we’re prepared to start asking: How will a policy change alter migration?
Who Migrates?
Inflows are Less Educated and More Foreign
Iowa has a lower rate of in-migration for degree-holders than the typical US state. This gap is large: the median US state has inflows over a third higher than Iowa. At the same time (as you can see if you click the interactive link), Iowa also attracts fewer non-degreed people, though the gap is smaller. So we can say that Iowa has lower inflows than the nation on the whole regardless of education category, but especially for degreed migrants.
We can also assess migration by foreign origin. I’m not talking about international migration here, just domestic migration of foreigners versus the native born. Iowa attracts much more in-migration of the foreign born than the typical state, but loses the native-born.
Finally, breaking the data down by income levels, Iowa has roughly typical inflows of both individuals earning under $25,000 and those earning over $75,000.
So overall, inflows are less educated and more foreign than the national average.
Who Migrates?
Outflows are More Educated and More Foreign
As the above graphic for out-migration shows, Iowa has higher outmigration of degreed people than is typical. Outmigration of the non-degreed is slightly lower than is typical for other states. Overall, we can say that Iowa’s outflows tend to be more educated.
For the foreign vs. native comparison, we see that Iowa has much higher out-migration of foreigners than the national average, but slightly lower native-born out-migration. Finally, based on income, Iowa has slightly higher out-migration for both categories.
For outflows, Iowa tends to be a disproportionate loser of degreed migrants, as well as foreign-born migrants.
Who Migrates?
Net Flows Show “Brain Drain”…
Or Do They?
When you take inflows and outflows together, you get net migration. Iowa’s net migration, based on just this data, looks like something out of an economic development authority’s nightmares. Let’s do some really terrible stereotyping here and think about what the above chart could mean.
Poor, uneducated foreigners are moving in and taking jobs, while Iowa’s higher-earning, educated native-born are fleeing the state! Oh no! Think of the tax revenues, think of the cultural change, think of the children! How can Iowa survive this terrible flight of “job-creators” and the “creative class”?
To understand migration, we can’t just look at any targeted set of data, but rather have to find the right set.
Who Migrates?
Migration Has a Life Cycle
Iowa’s apparent “brain drain” is in fact exactly the opposite. When we look at migration by age group, this becomes crystal clear. Iowa gains minors (who mostly move with parents: so we can see this as Iowa gaining families). Iowa gains 30-somethings, who are probably parents and early- or mid-career workers. Iowa loses folks later in their career or retiring.
But holy cow, Iowa gains a lot of 18–19 year olds! That’s a 5% net migration rate. That’s quite large. Now it’s true, Iowa loses 20-somethings, but the effects don’t offset. From 2008–2013, Iowa lost about 8,000 people in their 20s, but gained about 22,000 people aged 18 to 19.
With this in mind, let’s revisit the net data shown above. Who has a higher income: a college student, or a pensioner in their 60s? Well, the pensioner, of course. Even if the student works full time as a minimum wage worker, chances are they will still make under $25,000, while at least some retirees (and many late-career workers) will make over $75,000. So if college students move in and retirees move out, it will look like the poor replacing the rich: but it’s really just the upwardly mobile replacing the already accomplished.
The same is true for educational attainment. How many 18 to 19 year-old college students already have a degree? I think it’s safe to say very, very few! But how many people in their 50s and 60s have a college degree? Well, at least some; maybe as many as 30 or 40 percent in some cases. So if college students move in and retirees move out, it will look like the uneducated replacing the educated: but it’s really just the natural cycle of education and training.
Finally, even foreign vs. native born discrepancies can be accounted for. Millennials are far more likely to be foreign-born than individuals now in their 60s, and many foreigners come to the United States to study. This also explains why many foreigners leave Iowa: they disproportionately come on J-1 visas, so are likely to stay temporarily, or apply to graduate school, often in other states.
So is Iowa experiencing brain drain? Hardly. The balance of the evidence suggests that Iowa is actually experiencing brain gain. Sure, a lot of degreed people move out, but that’s a good sign! Why? First of all, most of these young migrants stick around. Again, if we assume all of the migrant flows from 18 to 29 years old are educationally driven (not true, but a thought-provoking hypothetical), then Iowa’s net gain in “skilled migrants” would be 14,000 college-educated people. Sounds pretty good to me.
Second, we have to ask what motivates education. People don’t just go to school for the kicks: they have goals, ambitions, and aspirations. Many of those goals include opportunities beyond Iowa, perhaps for a whole life, perhaps just a few years. Iowa’s negative flow of degreed people is a sign that Iowa universities do a good job attracting, training, and then sending students to lives of success. This “negative” migration is in fact a symptom of a relatively successful university system.
By having more people connected to Iowa around the nation, Iowa businesses, workers,and researchers can develop wider networks of social and economic support, providing them an additional safety net in hard times, greater economic and social mobility, and greater exposure to new ideas that lead to innovation. And as a new project gets underway to actively engage this “Iowan diaspora,” the state may begin to enjoy even larger benefits from out-migration.
Who Migrates?
Iowa’s Migration Varies by Age
It turns out, Iowa has a fairly strong record on “young adult” migration. Numerous Minnesotan and Illinois young people end up in Iowa for their college education, and many of them end up staying in Iowa. While other states like Colorado, Delaware, Vermont, North Dakota, or Rhode Island have an even more positive young adult migration record, Iowa does better than most of its neighbors and regional peers.
By the way: notice that California is not particularly attractive to young people. Yet another migration myth.
For individuals over 40, Iowa’s migration rate is somewhat negative. It’s not the worst in the region, faring considerable better than Illinois or Michigan, and it’s quite similar to Minnesota. But it does perform worse than Wisconsin, South Dakota, Nebraska, or Missouri in terms of hanging onto people at the peak of their career, as well as retirees.
So what can we say about Iowa’s place in the migration life cycle? It draws in people hoping to improve on their skills and knowledge. Many stay, but many are equipped to go elsewhere, and to so, presumably to their benefit. Iowa attracts people in their 30s as well. But by the time they’re getting middle aged or older, many Iowa residents begin looking for other states to call home.
Where, you might ask? Well, let’s look and see.
Where Do Migrants Go?
Do Iowans Leave for Sun and Taxes?
Let’s start with two simple stories about “where” migrants go: they head to warm, southerly climes, and they look for low taxes. Let’s start with the weather narrative.
The above map shows Iowa’s “replacement rate” with each of several regions. A number under 100 means Iowa loses people to the region, over 100 means it gains. As you can see, Iowa gains the most from the frigid New England states, and loses the must to the sunny southwest. Score 1 for the “weather hypothesis,” right?
Then we have this map, divided into three regions: states with no income tax, states with the highest income tax rates, and the other states. As you can see, Iowa has the most lopsided and positive flows with the high-tax states, and the most lopsided and negative flows with the low-tax states. Point for the “tax hypothesis”!
Where Do Migrants Go?
Iowa’s Migration Corridors
But when we look at Iowa’s migration flows for each individual state, these stories break apart pretty quickly. Iowa loses to Arizona and Texas, but gains from Nevada and New Mexico. There are gains from New York and Connecticut, sure, but losses to Maine. And it’s true that Iowa loses people to Florida and Georgia, but it gains from North Carolina and Mississippi. For every region, there are winners and losers.
The states with the largest net flows with Iowa are Illinois, Arizona, Missouri, South Dakota, and Minnesota.
The regional explanations may have been tempting, but they just don’t hold water. The tax explanation is only a little better. Sure, Iowa loses to Florida, Texas, Washington, South Dakota, and Tennessee. But it gains from New Hampshire, Nevada, Wyoming, and Alaska: so having no income tax is no solution. On the other end of the spectrum, Iowa does gain or break even with every high-tax state. So do taxes impact migration? Sure, but not the way you think. I’ve written before on this topic at some length, so I won’t dwell on the taxes-migration debate here.
The above chart showed which states had large net migration balances with Iowa as a percent of Iowa’s population. Another way we can look at the data is to assess the net migration as a percent of the other state’s population. The above map shows each state color coded by its net migration balance with Iowa as a percent of its population. This shows that, from Illinois’ or Arizona’s perspective, Iowa looks rather less important than those states appear to Iowa. Meanwhile, from the perspective of the Dakotas, the migration balance with Iowa is very important, even as, from Iowa’s perspective, those states aren’t as big a deal.
This map, instead of showing the size of net migration compared to population, simply divides Iowa’s inflows from a given state by its outflows to that state. This shows how “lopsided” or uneven its flows are. For the most part, Iowa’s flows with neighbors are fairly balanced: gross flows are fairly large both directions, and Iowa just happens to have the edge against some, and be edged out by others. But for long-range migration, flows are much more lopsided. Flows from North Dakota, Connecticut, West Virginia, Mississippi, or Nevada are pretty much one-way, while flows to Virginia or Arizona are, likewise, pretty much one-way. Few Arizonans move to Iowa.
Where Do Migrants Go?
Iowa’s Migration Regions
I’ve defined 8 regions within Iowa based on metro areas, transportation networks, commuter zones, local migration flows, and other factors, as a way to take a closer look at Iowa’s migration. The above map shows how I’ve divided the state, and is also color-coded to match an interactive graph I’ll link to further down.
Interstate migration in Iowa heavily favors the Cedar Rapids and Iowa City area: which is unsurprising, given that this region includes the University of Iowa. Since Iowan migration is dependent on educational migrants, the localities with major universities (including Des Moines and Ames as well) will tend to get interstate migrants. This is especially true for the University of Iowa, which has a large postgraduate program that recruits out-of-state. Davenport and Dubuque also receive many cross-border migrants from Illinois.
Meanwhile, the Greater Council Bluffs area loses the most interstate migrants. This trend is overwhelmingly focused on migration just across the border into Nebraska, mostly by individuals who are between 30 and 60. The region also suffers some out-migration to Missouri.
For the rest of the state, and especially the more rural areas, interstate migration is comparatively small in terms of its aggregated net effects.
Where Do Migrants Go?
Some Excessive Detail on Iowa’s Regions
Have you ever found yourself thinking, “My life would be so much better if I knew the exact migration rate between Northern Iowa and states with no income tax”? No? Well, sometimes I have those thoughts. So I built a way for you to have an answer, just in case, like me, you have an unhealthy interest in specific migrant flows.
If you click the link to the interactive version of this graph, you’ll notice that there’s a dropdown menu. It has lots of options for various states and regions. Basically, you select a region, and it spits out the net migration rate in 2013 (as a percent of the Iowa region’s population) for each Iowa region. This is a pretty cool tool. For example, we can ask whether or not Iowans are fleeing to Arizona generally, or just from specific places:
Answer: almost every Iowa region loses people to Arizona. This is not a phenomenon driven by just one or two cities, but a statewide issue.
Or we could ask which regions attract the most Illinois migrants, on balance:
Well done eastern Iowa.
But maybe we don’t care about specific states. Maybe we’re interested in the “Rust Belt.” Here you go (with Illinois excluded, but there’s an option to include Illinois as well):
Cedar Rapids, Sioux Falls, and Davenport all gain from the Rust Belt, while Des Moines actually loses out to the region.
Check it out. Feel free to pass it along to others. And if you find yourself thinking, “Boy, I’m not from Iowa, but it would be cool if I had this for my state,” please get in touch with me.
Where Do Migrants Go?
From Iowa to Iowa
While we’re talking about Iowa regions, it makes sense to at least glance at migration within Iowa.
For in-state migration, the dominant trend is migrants from rural southern and northern Iowa moving to Des Moines. Some come for jobs, some for suburban living, and many for education, especially at Iowa State University.
Has it Always Been This Way?
A Brief History of Iowa Migration
Once upon a time, Iowa had far fewer people than it now has. Before it became a state in 1846, Iowa was peopled by settlers and Native American peoples, but their numbers were comparatively few next to the state’s current population. Iowa was peopled largely through migration. So sometime in the far distant past, the state received positive migration.
But has that happened since? Is Iowa fated to lose people to sunny low-tax states?
Iowa has had periods of in-migration, and in fact has had them quite recently. In just 2012, the ACS estimates that Iowa gained 3,000 people. In 2007, the state gained about 12,000 through migration. But of course, it lose 4,000 in 2011, and spent the entire decade of the 1990s losing people to migrants. Most of the 1980s too. And 1950 to sometime in the 1970s.
But the point is, Iowa’s migration hasn’t been flat: it changes over time in response to various outside factors and choices made within the state. It’s also worth noting that I use 4 sources to estimate migration. The orange and blue lines are, I think most accurate, coming from the Census and the American Community Survey. The red line comes from “Intercensal Estimates” that are fairly limited in scope. The green line comes from IRS Statistics of Income data, and track tax filers. Because many Iowa in-migrants are college students who may not file taxes, IRS data underestimates inflows and may overestimate outflows.
So what causes changes in Iowa’s migration rate?
Iowa’s net migration rate is correlated with the ratio of state personal incomes to national incomes. When Iowa incomes were high, migration was high, and vice versa. The most dynamic component of migration comes from the cycle of employment and unemployment, so anything that boosts jobs and income will tend to boost migration. Obviously numerous other factors are in play, but, in terms of a “single variable,” this is probably the best explanation.
Has it Always Been This Way?
Migration Corridors Over Time
The gray line above tracks Iowa’s overall migration according to the Census and ACS. The colored lines show Iowa’s migration balance with specific states.
Draw your attention first to the blue line. Iowa has gained people from Illinois every year since 1975. The size of that gain has fluctuated from 10,000 people to a few hundred, but it’s never gone negative.
Meanwhile, Iowa has fairly consistently lost people to South Dakota, Arizona, and Virginia. Notice the Arizona-Illinois relationship in particular. The blue and yellow lines are almost mirror images. When somebody moves in from Illinois, somebody moves out to Arizona. It’s kind of eerie. What could explain this relationship?
I don’t know for sure, and don’t have sufficient data to say with total confidence. But one thought is this: economic growth creates jobs and higher income. Higher income and higher migration of workers leads to higher prices, especially for scarce goods like housing. Furthermore, most migrants to Arizona are retirees, who may be very price sensitive. It seems likely to me that the same economic growth that attracts labor migrants may ultimately repel retirees: they don’t get new income (after all, they’re retired), but they do experience rising cost of living. If this is true, then Iowa and other states may face a kind of generalized tradeoff: you can either have worker migration or retiree migration, but, in the long run, probably not both. Certainly some states will be exceptions, especially if they are large enough to have very segmented markets within their borders.
Will it Always Be This Way?
How To: Mess Up Migration
With all this data about migration, you’d think I would be able to offer a “migration policy” for localities. Some set of incentives, programs, plans, and regulations could presumably maximize a locality’s migration. But ultimately, I have no such plan. There are several reasons why.
First, while migration has huge impacts on a person’s life and future income, it’s both challenging and ethically dubious to govern. People have a right of movement within the United States, so efforts to encourage or discourage migration can sometimes run into thorny constitutional territory. Moreover, the reality is that “potential future in-migrants” are not yet constituents: there’s a very real debate to be had about what duties a local policymaker may have towards such non-constituents. This is especially pressing for investment, when new firms may be given sweetheart deals ultimately paid for by tax revenues from existing firms. Programs intended to “target” migration may similarly create questions of justice and accountable government.
Many policies impact migration, from taxes, to occupational licensing, to military spending and personnel policies, to the structure and funding of higher education. In order to maximize the benefits of migration, policymakers should do the same things they should do anyways: pursue pro-growth, neutral tax policies, adequately fund essential public services, promote welcoming, community-friendly laws and law enforcement practices, avoid artifically inflating the local cost of living, and other factors. The reality is that migrants don’t move for migrant-friendly policies: they move for a chance to live a better life, in the stage of life they’re at.
Read the next post, where I outline migration trends around North America!
See posts on Kentucky, Georgia, North Carolina, Cincinnati, Atlanta, Minneapolis, the Bluegrass, and Eastern Kentucky.
See the previous post on my site!
Start the series from the beginning!
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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.
My posts are not endorsed by and do not in any way represent the opinions of the George Washington University nor the United States government or any branch, department, agency, or division of it. My writing represents exclusively my own opinions.
