In a way the net contributors are just circulating tax money, the net takers then buy the products from the contributors and so the money returns, in addition new industries slowly arise in the poorer member states, see Poland for instance, once with a lower standard of living than East Germany and now the fastest growing economy in Europe, they, unlike the UK, can afford a large modern army for instance, they are getting richer through their own efforts now while the UK's average citizens are getting poorer.