>really? source on that? What states exactly does that entail?

Is that really that surprising? The Census Bureau defines the midwest to be 12 states: Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin. Their accumulated GDP is 3.6 trillion vs California's 2.4 trillion or approximately 50% more(numbers found on wolfram alpha). But then that is 12 against one, not exactly exciting that the Midwest isn't a third world country.

Not sure how CMU and Pittsburgh ended up there though that is Midatlantic not Midwest. Probably just makes the math more favorable.