[goodcanadian]

I don't necessarily agree with the grandparent comment, but I think the mechanism at work is exchange rates. Because of the strong German economy (for example), if Germany still had a separate currency, that currency would be much more expensive than the Euro currently is thus making German exports more expensive. Conversely, the Italian Lira would be much cheaper making their exports relatively cheap. An argument can be made that the Euro therefore benefits the richer countries at the expense of the poorer ones.

There are other factors at play, of course, and I think that a complete analysis would defy any simplistic explanation. Compare to the US dollar: does New York benefit from a common currency at the expense of Louisiana?

[mattmanser]

Not entirely, as federal dollars pay for army bases, manufacturing projects, etc. across the country, resulting in significant redistribution of wealth.

The EU has far, far less tax income, and for the last 10 years been spending all that money on the new entrants instead of Greece, Spain or Italy as it did pre-EU27. (And I would argue of course they should spend the money there for the greatest good).

So there's no redistribution through tax, and Germany benefits from a much weaker currency, while struggling countries can't use currency controls to kick start their trade.