The Eurozone: seventeen countries divided by a single currency

Reading an interesting article on VoxEU.org which reveals that, inside the Eurozone, "national supervisors require banks not to transfer cash out of their country so as not to be exposed in the event that the crisis degenerates".

I had no idea that that was happening. Though of course I had heard, along with everybody else, that European banks are entirely unwilling to extend credit to peripheral-country banks generally and selected weaker banks in core countries, I had assumed that that was simply every-man-for-himself prudentialism. Though that news is stunning enough, it's the conclusion the author draws from it that had me admiring its neatness:

We have arrived at the paradox of having a single currency with 17 bank and public debt markets segmented by national borders, charging their customers different interest rates. Such a situation cannot last long.