I can name the fastest growing national economy in the USA. It's easy...there is only one nation. In Europe, there are 50... how hard to get can this be?
The question of which US state has the fastest growing economy is equally interesting as the GP's question about European economies.
http://en.m.wikipedia.org/wiki/List_of_U.S._states_by_povert... http://www.sciencedaily.com/releases/2008/10/081031102640.ht... Between states it ranges from 5% to 20%. Between countries in Europe it ranges from 10% to 20%. I'm sure the figures aren't directly comparable, but it at least suggests that there's a similar level of economic diversity.
Your statistic shows poverty rate. The fact that there is greater variation between states in the US than between countries in Europe just shows what many of us have known for years: even if your economy sucks, the worst-off do better in Europe than in the US. In other words, the US is a great place to be if you are wealthy and successful. Europe is a much better place to be if you are anyone else.