Common currency hasn't delivered even economies
The creation of the euro was supposed to smooth out differences in the economies of the nations that adopted the common currency. Three years into a smoldering crisis, euro-zone nations have diverged, and many analysts feel the currency zone’s future will not be secure until that trend reverses. The euro was introduced in 1999 and entered circulation in 2002. Read related article.
Sources: Eurostat, Organization for Economic Cooperation and Development, World Bank. The Washington Post.