There is a distinctive “stuck belt” across the middle of the country running from Pennsylvania, Ohio, Michigan, Wisconsin, and Iowa, down through West Virginia and into the Sunbelt states of Kentucky, Alabama, Mississippi and Louisiana. Mobility is largely a bi-coastal—plus Rocky Mountain state—phenomenon.America can be divided into two distinct classes, the stuck and the mobile. The mobile possess the resources and the inclination to seek out and move to locations where they pursue economic opportunity. Too many Americans are stuck in places with limited resources and opportunities. This geography of the stuck and mobile is a key axis of cleavage in the United States.
Emphasis added. The mobile are able to move to places where one can best explore personal economic development. There is a glut of underutilized talent in the Rust Belt. That's good news for industry. Captive labor is cheap.
Being stuck highlights the problem with retention strategies. It's a poor use of valuable talent. Shrinking cities are struggling because of too little brain drain and not enough attraction of the mobile class.