Excessive exchange rate fluctuations among the major currencies is the central concern of the paper by Benoît Cœuré and Jean Pisani-Ferry. Much of the motivation for the European Monetary Union was to eliminate, once and for all, such fluctuations among continental European currencies. And Cœuré and Pisani- Ferry discuss, in a comprehensive and even-handed way, the case for containing fluctuations among the remaining major currencies—the dollar, the euro, and the yen—whether taking a rules-based approach favored by the continental Europeans, or taking the more discretionary approach favored by the United States.