I found this interesting:
One of the underlying problems with the Euro is that the impetus behind the establishment of the single currency was political not economic. Procrustean rather than pragmatic, its 'one size fits all' approach has proved problematic when applied to wildly divergent economies and has, for example, played no small part in Germany's current difficulties. Goran Persson, Sweden's prime minister, seems to have learned nothing from this experience. His latest argument (quoted by Reuters today) as to why Sweden should sign up for the Euro seems to be based more on politics than the prosperity of the people he is supposed to represent. "I see a more influential European Union, " he says "as an ever more important actor on the international scene. For everyone who is scared of living in a world where there is only one big actor, there is every reason to attach more weight and effort to strengthening the European Union…We in Sweden can contribute actively by stepping forth to work constructively for the common currency." Now that's what I call scary.
I spent a summer in Denmark taking an course in International Business. For my final paper, I wrote about how a more integrated European Union would put pressure on the large social service budgets of most European countries. My logic was that with a standard currency and less regulation, there would be easier movements of captial and labor across borders. This would cause companies to locate themselves where they could make the highest after-tax profit, and thus cause EU countries to use tax rates as a way to compete for business. The lower tax revenues would strain the social care systems.
I think the initial reasons for an EU were economic, but they have become political. Now they are jumping into things without thinking them through all the way. Germany is already having problems, and I don't think we really seen the worst of it. There is still much integration to be done.