[gph1]

The problem with EZ countries is precisely that you can't "take them together" because there is no centralized fiscal agent. You need this because there has to be fiscal transfers between weaker and stronger nations or else face growing imbalance of payments, and with the right catalyst, financial crisis. That's why the U.S. works as a monetary union.

[fauigerzigerk]

There are fiscal transfers within the EU and there are other ways to rebalance like freedom of movement for workers. But you are right that it doesn't go far enough. Deeper integration is undoubtedly needed.