The problem is that, in a world of floating exchange rates, as Italy was before the euro, if one country is subjected to a shock which requires it to cut wages, it cannot do so with a modern kind of control and regulation system. It is much easier to do it by letting the exchange rate change. Only one price has to change, instead of many.
Milton FriedmanA private enterprise system needs some measuring rod, it needs something, it needs money to make its transactions. You can't run a big complicated system through barter, through converting one commodity into another. You need a monetary system to operate. And the instability in that monetary system is devastating to the performance of the economy.
Milton FriedmanEconomics has become increasingly an arcane branch of mathematics rather than dealing with real economic problems.
Milton Friedman