[ameister14]

The problems aren't identical. They may appear so because some of the symptoms are the same, but the root causes in Ireland, for instance, are far different than in Greece.

Spain is closer to Ireland in terms of housing market effects on economic downturn, but ultimately each economy functions on a different system, so it's not entirely wrong to attribute economic problems to separate causes. There is some overlap, of course, but it's definitely not identical.

[lyudmil]

I agree the situations aren't identical, but what theory do you think best explains all the observations?

Just to be clear, my answer is: Each country's problems are rooted in the collapse of the US housing market and the resulting financial crunch. The country-to-country variations are there and they're significant, but secondary.