This brings to mind an interesting point- economic migration. An Alabaman(?) wanting to set up a start up is likely to move to california or new york- suppressi

This brings to mind an interesting point- economic migration. An Alabaman(?) wanting to set up a start up is likely to move to california or new york- suppressing the GDP of Alabama and increasing it for CA/NY. The same migration applies to the already-rich. Similarly, on an international scale, the USA is likely to be the destination of choice today. So as we see China begin to surpass the USA economically, the effect of any change of 'preferred economic migration destination' will likely amplify the natural GDP changes.