At the time of the formation of the euro, I would say most American economists said that's not a good idea; that's not a currency area that makes sense. And the answer from Europe was, 'How is Missouri and Mississippi a currency area?' But the flaw in that was not recognizing the importance of mobility.

A lot more people are willing to invest in bonds denominated in euros. And there was the fiscal discipline argument, which is that this tied the hands of countries the market hasn't always trusted, which also helped them borrow at low rates.

In Michigan, in the mid-'80s, the unemployment rate goes way up because a lot of factories shut down. And then, the mid-2000s, to pick a date, the unemployment rate in Michigan isn't that much higher than in the rest of the country. But the main way that happened is people moved.

Austan Goolsbee Quotes