KC and Pittsburgh metro areas have populations over 2M. There are a lot of smaller metro areas that are far rural, but aren't big cities - for example, my home

KC and Pittsburgh metro areas have populations over 2M. There are a lot of smaller metro areas that are far rural, but aren't big cities - for example, my hometown - Erie, PA, which has a metro population of just over 275k - is very much a city - but is too far from Pittsburgh to benefit from their economic growth. Pittsburgh is fine, but Erie is in decline. If "middle america" refers to every non-rural city between the coasts, then it is a meaningless term. There is too much economic variation to lump them all together for a single analysis.