State economies do differ dramatically though, and monetary policy can indeed affect them in opposite ways at least for a while. And state revenues are almost entirely collected by the state aren't they? There are funds for interstates and railroads, and schools, but often schools are primarily funded at the city level by property taxes.

There is really just the US economy. We would not say that Pennsylvania is in recession but New York is not.

The major difference between states is tax rates. Labor, transacting, anything else economically is practically transparent and frictionless.