Planet Money recently did a report on the difficulty of maintaining high economic productivity in southern Italy. I won't rehash the specifics of the story, but, I think it is important to get a visual sense of just how large the contrast between the south and north of Italy is. Too often we speak of nation-states. Nation-states are real, and they are important, but they are often not comparable. Just like comparing the USA to Sweden is only marginally informative, so comparing a small nation like Ireland to a more substantial one like Italy is deceptive. Here is a 2008 regional GDP map with sub-national breakdowns. Though some of the values are certainly lower now (basically, everything outside of Germany and Sweden), the relationships still hold.
There has been a gap between the north and south of Spain and England, as well as the west and east of Germany, but ...
