Seems a little inaccurate. My county in Appalachia is showing 17% higher and blue. The mean salary there is about $20k/yr and the unemployment rate is at least 20%.
I need to dig into the paper's methodology myself, but a similar situation struck me as possible for the high income areas that show low gains.
For example, say you grow up rich in the Bay Area. Then move to the midwest for work. Your household income in the Bay growing up might have been 300k. Then in Minneapolis, MN you and your husband earn 200k total.
You're standard of living has stayed the same or even increased, even though your household income has gone down by 33%.
