Hegemonic stability theory has been the traditional explanation in International Political Economy for the trend from fixed to floating exchange rates which was brought about by the collapse of Bretton Woods. This approach is found to be problematic. A more powerful explanation is the postwar rise in capital mobility, which produces a trade-off between exchange rate stability and policy autonomy. Preferences for these two policies have been a function of perspectives on economic policy and the degree of central bank independence. Independent central banks prefer domestic policy autonomy to exchange rate management, as they have no socio-political incentives to produce competitive, stable exchange rates. Their interests are predominantly in achieving low domestic inflation. In addition, current perspectives hold that the best way of securing international exchange rate stability is to pursue stable macroeconomic policies at home, resulting in the predominance of floating exchange rate policies. This trend will continue into the near future despite opportunities for international cooperation presented by the rationalization of world monetary politics into a G3 following the introduction of the euro. This may have adverse effects on the global economy for three reasons. First, there is a long-term danger that triad regionalization will result in a revival of neo-mercantilist policies, in which the exchange rate could play a part. Second, a high proportion of world trade and finance will be denominated in dollars and euros, rendering the stability of the dollar/euro exchange rate a global public good. Third, dollar/euro exchange rate misalignments which harm either the U.S. or EMU will be harmful to the global economy because of the high percentage of world GDP accounted for by these two areas