Why trailer parks are all over rural America, but not Iowa
Trailer-park America is vast - about 18 million people lived in a mobile home in 2015. In most counties, trailers outnumber apartments. In some, mostly in Florida and Georgia, they even outnumber standard single-family homes.
For the most part, the outline of this often-marginalized swath of America conforms to stereotype. It's rural, and it's poor.
The highest share of mobile homes are in the rural South and Southwest, in Sun Belt retirement communities, and on Indian reservations. They attract residents of every race and origin (with more American Indians and fewer African Americans than the population at large) and, outside of cities and densely populated coastal areas, they're everywhere. Everywhere, that is, but the Corn Belt.
For the purposes of this post, mobile homes or trailers are built at a factory and towed to their final destination. They are distinct from RVs, which are not used as stationary residences, and modular homes, which are manufactured in pieces and assembled on site.
It's an oddball correlation. What is it about corn that made it the antidote to mobile-home living? Is it just a coincidence?
Well, we think we've found the key factors, but we'd love to hear your explanations.
1. Farmland isn't likely to run dry or move to Mexico
The Corn Belt's deep topsoil, a legacy of the tall grass prairie that was plowed over by early white settlers and eventually replaced by maize, creates an economic base that isn't as likely to evaporate (at least within the next century or so) as it is in areas that depended upon manufacturing, mining or logging.
To be sure, farming is subject to near-catastrophic booms and bust cycles of its own, such as the crisis that inspired the Farm Aid concerts in the mid-1980s. Then, a few years of strong commodity prices encouraged farmers to borrow, invest in their farms and ramp up production.
When prices didn't hold up, the new production flooded the market, exacerbated the problem and left farmers with unsustainably high debt, triggering the now-familiar "farm bust." It's a familiar cycle: According to the Wall Street Journal, the country is in the midst of "the next American farm bust" at this very moment.
But in the long run, corn and other crops seem to have provided a buffer against the persistent poverty that has led to widespread mobile-home adoption in other regions.
2. Population in the Corn Belt peaked a century ago, and it hasn't needed extra housing since the dawn of the mobile-home age
According to Census Bureau figures, Americans made most use of mobile homes from the 1960s to the '90s. If a region didn't need affordable housing during those decades, then it probably hasn't added many mobile homes overall.
Mobile homes became a less attractive option around 2000, according to the Atlantic's Derek Thompson, when easy credit made it more affordable for low-income families to buy full-scale homes instead of manufactured ones.
Home manufacturers' problems continued during the Great Recession, when home and condominium values plunged. Why would you shell out for a trailer that would depreciate over time when you could instead buy low on a real estate asset that was likely to regain its value?
Meanwhile, the retirees who would have otherwise bought mobile homes in the Southeast hung on to their existing homes, waiting for their mortgages to pop back above water. And the ones who were in the market were increasingly looking toward modular homes, which are assembled on site instead of trucked in.
Rural Iowa, at the heart of the Corn Belt, has rarely found itself facing a housing crunch. The state has grown just three-tenths of a percent per year since 1900, making it the slowest-growing state in the country over that entire time. The corn-growing counties in particular have tended to lose population - many set their all-time high-water mark in 1900 or earlier.
Farmers needed those higher populations in the prewar era, because far more manual labor went into harvesting each acre. But as combine harvesters replaced farmworkers, the workers left their farmhouses, and a persistent housing surplus was born. It continued into the '70s and '80s.
Iowa State University historian Pamela Riney-Kehrberg said that while rural parts of the state have experienced some periods of growth during the mobile-home boom years, all of them occurred at times when there would have been plenty of cheap housing available.
"By the 1980s, the rural population was falling fast, leaving lots of available, inexpensive homes," Riney-Kehrberg said. "A lot of the rural, industrial growth in areas like meat packing also came after the depopulation of the 1980s, which meant that workers had access again to available, inexpensive housing left behind by departing others."
3. Corn prices made it more expensive to plow under crops to build mobile home parks
On the other side of the coin, it might have been getting harder to find affordable land to build trailer parks. Eighty-five percent of Iowa is covered in farms. There are only four other states above that level, and they're all nearby Great Plains states that host the western most tendrils of the Corn Belt: Nebraska, the Dakotas and Kansas.
During much of the period in question the price of farmland was either rising during a farming boom or the population was falling during the bust. There was little space in between in which demand for land for cheap housing overlapped with the availability of cheap land.
4. Corn is a highly mechanized crop that doesn't require as many migrant workers
Riney-Kehrberg also pointed out that because corn is less labor intensive, Iowa and its neighbors demand fewer migrant workers than other agricultural states. And while it's hard to find data on such a transient and poorly documented population, anecdotes suggest migrant workers are often lodged in manufactured homes.
The data we do have (immigration visas, which only cover a fraction of all migrant workers) support the Iowa State professor's theory. According to the Labor Department, more visas are granted for work on crops such as melons or sweet potatoes than on corn and Iowa ranks behind 17 other states in terms of visas granted, even though U.S. Department of Agriculture figures show it ranks behind only California in overall agricultural production.
5. Corn grows in the summer, but trailers are planted year-round
Trailer parks tend to be built in warmer climates, while corn is grown in colder ones. Riney-Kehrberg pointed out that the entire Upper Midwest, with the exception of some Indian reservations, tended to have fewer manufactured homes than the rest of the country. "Mobile homes are not the preferred place to endure cold temperatures and high winds," she said.
That brings us one more classic culprit: tornadoes. Those storms and manufactured homes are so intertwined in the national consciousness that the government explains tornado damage ratings based on how much havoc they wreak on trailer homes. An F-1 is "mobile homes pushed off foundations or overturned" while an F-2 is "mobile homes demolished." It goes all the way up to F-5: "Incredible phenomena will occur."
That hasn't deterred mobile homeownership in Mississippi and Alabama - which have some of the highest rates of mobile homeownership and tornadoes in the nation.
But for the Corn Belt, weather could be just one more good reason for choosing a home that would stay put.Story by Andrew Van Dam. Van Dam covers data and economics. He previously did similar work for The Wall Street Journal, and dissimilar work for The Boston Globe and The Idaho Press-Tribune.