The Mendoza Line

By David Mendoza - Monday, May 5, 2014

The great Walt Hickey of FiveThirtyEight wrote two excellent articles about the ambiguity of which states constitute the Midwest and the South. On Wednesday, Hickey released the data from his posts on GitHub and asked readers to remix his work. Specifically, Hickey wanted people to use the zip code data from his SurveyMonkey Audience poll results to answer these questions:

Where are the Southern and Midwestern expatriates? Do local definitions of regions explain the Midwestern inability to agree on the core states? And how split are residents of difficult-to-categorize states, such as Missouri and Virginia, on their own identity?

Where are the Southern and Midwestern expatriates?

For the purpose of this question, a Southern or Midwestern “expatriate” is someone who does not live in the states that a majority of survey respondents identified as either part of the South or Midwest.

According to the zip code data, the most Southern expatriates were located in states just outside of the South: Oklahoma and Maryland. As the map below shows, there were 30 zip codes in Oklahoma and 21 zip codes in Maryland with self-identified Southerners residing in them. The next two states were much farther from the region: California and Washington. Interestingly, there were no Southern expatriates living in the Yankee stronghold known as New England.

The state with the most Midwestern expatriates was Colorado. There were Midwesterners living in 37 different zip codes within the Centennial State. Other states replete with Midwesterners included Oklahoma, Pennsylvania, and California. Again, no self-identified Midwesterners lived in New England.

Where do the people who excluded Illinois from the Midwest live?

Eighty-one percent of Midwesterners considered Illinois to be part of the Midwest — the highest percentage of any state in the SurveyMonkey Audience poll. Yet, as Hickey noted, this was a surprisingly low number for a state that is quintessentially Midwestern.

The embedded Google Map above displays the percentage of respondents who classified Illinois as part of the Midwest by zip code. More than 75% of respondents in green zip codes agreed that Illinois was part of the Midwest, while red zip codes agreed less than 25% of the time. Zip codes that appear orange (25-50%) or yellow (50-75%) were more divided. You can click on individual zip codes to see the exact percentage of respondents who agreed Illinois was in the Midwest.

So in which zip codes do the doubters of Illinois’ Midwesternness live? Mostly outside of the Midwest. For example, majorities of the respondents who resided in zip codes located in Nebraska, Montana, North Dakota, and Wyoming rejected the Prairie State’s status as part of the Midwest. However, even within the Midwest, there were pockets of dissent. Less than two-thirds of the zip codes in Minnesota and less than half of the zip codes in Kansas included Illinois part of their regional union. There wasn’t even a unanimous decision about Illinois in Illinois. Respondents in three zip codes located in Hampshire, Savoy, and Schaumburg didn’t agree that the state they live in was in the Midwest.

Does anyone know what’s going on with Missouri?

Hickey described Missouri as the “geographic equivalent of the last kid picked during dodgeball.” If this were a dodgeball game, 56% of Midwesterners would select the Show Me State for their team and only 15% of Southerners would do the same. But if it was up to Missourians, which side would they choose?

Below, I mapped the results from each regional SurveyMonkey poll by zip code. The map on the left uses the data from the survey of Midwesterners and the map on the right uses the data from the survey of Southerners.

Immediately, we can see that there are more green zip codes on the map on left than there are on the one on the right. Among the 60 zip codes in Missouri included in the SurveyMonkey results, 98% agreed that Missouri was part of the Midwest. By contrast, in the other survey, there were only 4 zip codes in Missouri with self-described Southerners in them. So, at least among Missourians, they consider themselves to be part of the Midwest and not the South.

Is Pennsylvania part of the Midwest?

On Twitter, the editor-in-chief of FiveThirtyEight lamented the fact that “almost no one” agreed with him that Pennsylvania was in the Midwest. Indeed, according to Hickey’s original article, only 6% of respondents identified the commonwealth as part of the Midwest — half the number that included Colorado. Only West Virgina was considered less Midwestern than Pennsylvania.

In 2006, Meghann Marco explained in McSweeney’s why Pennsylvania should not be acknowledged as Midwestern.

People in Pittsburgh sound Midwestern. They say “pop” rather than “coke” or “soda,” but Pennsylvania also has Philadelphia. Philadelphia is not Midwestern. Also, Pennsylvania is a Commonwealth—very un-Midwestern-y.

Among respondents in zip codes inside of Pennsylvania, 83% disagreed with Silver. Pennsylvanians in 25 of the 30 zip codes concurred with other Midwesterners that they are not in the Midwest. Of the five zip codes in the minority, four were located around Pittsburgh and one was outside of Philadelphia. Additionally, 27% of the 117 zip codes in Ohio included their neighbors as fellow Midwesterners.

If you have any questions or would like to request an additional map not included here, please leave a comment below.