Under the Bretton Woods system, central banks of countries other than the United States were given the task of maintaining fixed exchange rates between their currencies and the dollar. They did this by intervening in foreign exchange markets. If a country's currency was too high relative to the dollar, its central bank would sell its currency in exchange for dollars, driving down the value of its currency. Conversely, if the value of a country's money was too low, the country would buy its own currency, thereby driving up the price.
The Bretton Woods system lasted until 1971. By that time, inflation in the United States and a growing American trade deficit were undermining the value of the dollar. Americans urged Germany and Japan, both of which had favorable payments balances, to appreciate their currencies. But those nations were reluctant to take that step, since raising the value of their currencies would increases prices for their goods and hurt their exports. Finally, the United States abandoned the fixed value of the dollar and allowed it to "float" -- that is, to fluctuate against other currencies. The dollar promptly fell. World leaders sought to revive the Bretton Woods system with the so-called Smithsonian Agreement in 1971, but the effort failed. By 1973, the United States and other nations agreed to allow exchange rates to float.
Economists call the resulting system a "managed float regime," meaning that even though exchange rates for most currencies float, central banks still intervene to prevent sharp changes. As in 1971, countries with large trade surpluses often sell their own currencies in an effort to prevent them from appreciating (and thereby hurting exports). By the same token, countries with large deficits often buy their own currencies in order to prevent depreciation , which raises domestic prices. But there are limits to what can be accomplished through intervention, especially for countries with large trade deficits. Eventually, a country that intervenes to support its currency may deplete its international reserves, making it unable to continue buttressing the currency and potentially leaving it unable to meet its international obligations.
Next Article: The Global Economy
This article is adapted from the book "Outline of the U.S. Economy" by Conte and Carr and has been adapted with permission from the U.S. Department of State.