The Hydraulic Theory of the Euro
Jean-Baptiste Queru recently posted what I call the "Hydraulic Theory" of currency union. Other than an overall theme of "Blame Germany", it's somewhat discombobulated, but I think the basic point is: The core mechanism that allows multiple states to share the same currency is pretty simple: since the weaker states can't devalue their currency to compensate for their trade deficit with the stronger ones, money has to flow from the stronger economies to the weaker ones in order to maintain the balance. Which is pointing out that balance of payments in an identity: your surplus + my deficit = 0 This identity doesn't cause the balance of payments, rather it merely identifies that if someone owes money, someone else must be OWED that money. Consider if I told you that last year I racked up $20k in debt (credit card). You could correctly infer that I spent $20K more than I made last year. It would be ABSURD to say that the debt cau...