"Each of the 380 million residents of the 15-nation EU produced $25,200 in goods and services last year, while 287 million Americans produced $35,500 apiece, according to the Paris- based Organization for Economic Cooperation and Development."
This says it all. I have been the most vocal proponent of PRODUCTIVITY as the MAIN economic indicator of a nation/region's health. Here 'tis again.
Searching for statistics I have found a lot of areas with pro-capita GDP above 30.000$ (Bavaria of Germany, Inner London, Luxembourg...). I also found regions with values between 10,000 and 15,000, that are quite low (large areas in Spain,Portugal,Greece,Southern Italy,Eastern Germany...). Such differences are astonishing, considering that rich areas have unemployment firmly below 5%, while the poorest usually have more than 15% (and sometimes 21%) of their workforce unemployed. First, Europe must enhance mobility A LOT.
I have found a lot of papers on the argument but no detailed statistic , by now.