It might be wise to remember that this map will reflect persons in the military moving also.
Orange county California looks like a red explosion!
I was wondering about that. I checked El Paso County, CO (Air Force Academy) and noticed far more red than I expected. Part of it might be due to the graduating class spreading out to fewer places than the incoming class is arriving from. Plus, the IRS knows about each graduate, but might not find out about you until you arrive, so your move in doesn't get counted.
I wonder if there's a map adjusted for things like college attendance and military transfers.
Those are the people came here and then lost their jobs, homes, and or just could not afford to live there, and are now heading back to where they came...Broke....