From the NYT:
How Connected Is Your Community to Everywhere Else in America?
By EMILY BADGER and QUOCTRUNG BUI SEPT. 19, 2018
America is often described as a place of great divides — between red and blue, big cities and rural towns, the coasts and the heartland. But our social lives are shaped by a much stronger force that ignores many of these lines: distance.
In the millions of ties on Facebook that connect relatives, co-workers, classmates and friends, Americans are far more likely to know people nearby than in distant communities that share their politics or mirror their demographics. The dominant picture in data analyzed by economists at Facebook, Harvard, Princeton and New York University is not that like-minded places are linked; rather, people in counties close to one another are.
Here’s the academic paper.
Even in the age of the internet, distance matters immensely in determining whom — and, as a result, what — we know.
So, what happens is that there aren’t all that many interesting findings of cross-country links. Here’s one: People in Cook County (Chicago), IL have a lot of Facebook ties to relatives in the Mississippi Delta, due to the Great Migration of Mississippi blacks up the Illinois Central Railroad to Chicago. (There also a Milwaukee-Mississippi connection.)
A commenter with excellent eye-hand coordination got his cursor on tiny New York County (i.e., Manhattan):
Lots of connections to Fr. Lauderdale, Rocky Mountain ski towns, midwestern college towns like Ann Arbor and Madison, plus Atlanta, Austin, LA, the Bay Area, and Seattle. A broad connection to the coastal Carolinas: I wonder whether that is people in Manhattan having come from there or going there?
A few other connections are that college towns are connected to each other and so are American Indians:
College towns are all super connected to each other. This map shows Tompkins County, New York, home of Ithaca and @Cornell University. All the random bold blue spots around the Midwest are other college towns. pic.twitter.com/1S9CfegGda
— Nic Moe🗽 (@NicWillMoe) September 20, 2018
The Okies of Kern County, CA are connected to Sooners back home in Oklahoma.
Houston is connected to the new oil patch in North Dakota.
But mostly people are connected on Facebook to people in their general vicinity.
One perhaps unexpected finding is that state lines matter to Facebook friends.
For example, if you pick out random counties in the middle of Iowa, Oklahoma, or Alabama, you can see the outlines of the states.
There tends to be a sharp falloff in Facebook friends right across the state lines.
I suspect this is tied to state colleges. People from Alabama are more likely to go to college in Alabama than in Georgia, Mississippi, Kentucky, or Florida. If you live just east of the Alabama-Georgia border, it costs something $100k less to go to the U. of Alabama than to the U. of Georgia.
So they keep up on Facebook with their friends in Alabama. Plus, people in Alabama pay a lot of attention to college football in the two big public colleges, U. of Alabama and Auburn.
– This could also be tied to state government.
– Another possibility is that, all else being equal, people are less likely to move across state lines, perhaps due to sports rooting rivalries. Interestingly, the Upper Peninsula of Michigan is more tied to Green Bay, WI on Facebook than to the Lower Peninsula of Michigan, suggesting that ease of driving and possibly NFL rooting matters more than state government ties.