January 1, 2009, is the tenth birthday of the euro. On this occasion, everyone has been taking stock. The record of the euro shows both pluses and minuses. Looking back, the euro has in many ways been more successful than predicted by the skeptics — many of them American economists. (The Europeans love to quote Martin Feldstein as having predicted that EMU could lead to civil war.) The historic transition to a monetary union among 11 countries in 1999 went smoothly; the euro instantly became the world’s number two international currency; and the officials of the European Central Bank (ECB) have from the beginning worked as citizens of Europe rather than as representatives of home constituencies. After a rocky start, the euro has achieved a strong value; the ECB has achieved a strong reputation (the tradition of the Bundesbank has not been diluted as feared); and new members to the East have achieved membership in the club. Slovakia becomes the 16th country to join, on January 1.