Q. How and why did Europe set up its single currency?
Answer: The why part of the question is associated to large fluctuations in the exchange rates between the European countries disturbed trade. As well one of the major reasons was to design a way to prevent future world war. The how part of the question is associated to the fall down of Breton woods and the European Currency reform of 1969-1978. The Werner Report of 1971 set up a three-phase program to lead to the EMU.