OK... non Econ major here....

[applegrove]

10. The Greeks got into the EU by lying about their debt. Then they used the fact they

were a part of the EU to borrow even more money. They used that borrowed money to pay themselves huge salaries and great early retirements. It was one huge fraud in that case but legal. It was different in every country.

So too having a common currency means that when poor countries got into trouble they no longer had control over monetary policy and could not devalue their currency (doing this would make their goods cheaper and imported goods more expensive and would help improve their economies).

Iceland had huge speculative banks that were run by former fishermen.

varied reasons. All of them having to do with the wrong assumptions being made, speculation taking place based on faulty financial assumptions, and then huge crashes.

USA was guilty of this too.