Warning: You can't have One Economy if you don't have One Government

Sadly, this warning comes a little late. But Bill Mitchell makes the same observation today:

All the prior studies of potential economic and monetary integration in Europe like the 1970 Werner Report and the 1977 MacDougall Report had concluded that the only viable architecture for a common currency would require a substantial ‘federal’ fiscal capacity, legitimised politically, by a properly constituted federal parliament.