Just a note: I see that some readers are confused when I talk about how the coming of the euro led to low interest rates in the European periphery.

It’s actually very clear in the data:

Eurostat

As the euro became a done deal, countries that had previously had to pay a large interest premium found themselves able to borrow on the same terms as Germany; this translated into a big fall in their cost of capital. The result was bubbles, inflation, and in the aftermath of the bubbles and inflation, what you see now.