why is northern Italy so rich and southern Italy so poor?

by idontIikecats

I was reading article today claiming that northern Italy is richer on average then most of Germany while southern Italy is poorer on average then most of Greece, why the discrepancy?

SirHerpMcDerpintgon

Here's a few previous discussions relating to this topic as posted by /u/Searocksandtrees.

http://www.reddit.com/r/AskHistorians/comments/2glnfr/why_is_northern_italy_so_much_richer_than_the/ckkdrcd

ouat_throw

I guess a piggyback question, did the reconquest of Italy by the Eastern Roman Empire have anything to do with this disparity at all?