The floating exchange-rate system emerged when the old IMF system of pegged exchange rates collapsed. The case for the pegged exchange rate is based partly on the deficiencies of alternative systems. The IMF system of adjustable pegs proved unworkable in a world in which there were huge volumes of internationally mobile financial capital that could be shifted out of countries in balance-of-payments difficulties and into the stronger nations. The earlier gold standard system had likewise contained substantial defects. Under some circumstances, it required countries to go through a painful deflation. The gold standard, it is widely held, made the Great Depression of the 1930s even deeper than it might otherwise have been.

Three major, interrelated hopes were expressed when flexible exchange rates replaced the collapsing IMF system of pegged exchange rates in the early 1970s. First, flexible exchange rates would allow currencies to hold at or near their fundamental equilibrium values; national authorities would not feel obliged to defend exchange rates that were severely out of line. Second, deficit countries would be able to reestablish their international competitiveness without going through the painful deflationary process required by the old gold standard and without facing the political embarrassment of abandoning an established par value. Finally, the national monetary authorities would have a substantial degree of independence to pursue the most appropriate domestic monetary and fiscal policies, without being severely constrained by balance-of-payments pressures. In practice, exchange-rate flexibility turned out to be more complicated than its proponents had anticipated.

The pegged exchange-rate system collapsed in two speculative flurries against the U.S. dollar in 1971 and 1973. In each case, the dollar depreciated about 10 percent in terms of an average of other currencies. (In calculating an average exchange rate for the dollar, the currencies of each other nation is weighted according to the volume of trade of that nation with the United States.) After these initial adjustments, exchange rates of the major trading nations were generally quite stable for the next four years (late 1973–77), although there were some fluctuations. The dollar strengthened following the first oil shock, which occurred in 1973–74; because the United States still produced most of the oil it consumed, it was expected to be less severely shaken by high oil prices than would its major trading partners, especially West Germany and Japan. In the 1973–77 period, the major exchange-rate change was a fall in the British pound sterling by about 30 percent when measured in terms of dollars.

In late 1977 the dollar entered a period of instability. As the U.S. economy expanded and inflation increased, U.S. goods became less competitive on world markets. In response, the dollar began to slide downward. This raised the price of imported goods in the United States, adding to inflationary pressures. The United States seemed in danger of entering a wage–price–exchange rate spiral. Anticipating worse to come, speculators began to unload dollars, moving the exchange value of the dollar even lower. During the 1977–79 period, the average exchange value of the dollar declined by about 15 percent.

Faced with a rapidly deteriorating situation, the United States tightened its domestic policies sharply. In particular, monetary policy was tightened in order to combat the rapid inflation. This experience provided one early, important lesson about flexible exchange rates. Even though flexible exchange rates provide some independence for domestic monetary policies, domestic policies cannot be made without concern for international complications. This is true even for a large, prosperous economy, such as that of the United States.

During the late 1970s, the U.S. dollar was threatened with a collapse. By the mid-1980s the opposite had occurred: the dollar had soared—rising about 80 percent. A number of forces contributed to this rise. One was U.S. fiscal policy: tax rates were cut sharply, and budgetary deficits ballooned. Large-scale government borrowing added to the demands on financial markets, leading to high interest rates. This encouraged foreign asset holders to buy U.S. bonds. To do so, they bought dollars, creating upward pressure on the exchange value of the dollar. In turn, the high dollar made it difficult for U.S. producers to compete on world markets. U.S. imports rose briskly; exports were relatively sluggish, and the U.S. trade deficit soared.

Because of strong competition from imports, U.S. producers of automobiles, textiles, and a number of other products lobbied for protection. Under the threat of unilateral U.S. actions, the government of Japan was persuaded to impose “voluntary” limits on exports of cars to the United States. There were concerns—both in the United States and in its trading partners—that the United States might adopt a much more protectionist policy because the high exchange value of the dollar was making it so difficult for U.S. producers to compete.

Faced with this unwelcome prospect, senior officials of the “Group of Five” (France, West Germany, Japan, the United Kingdom, and the United States) met at the Plaza Hotel in New York City in 1985. In the “Plaza Agreement,” they declared their intention to bring the dollar down to a more competitive level, if necessary by official sales of dollars on exchange markets.

This episode raised fundamental questions about flexible exchange rates, leading some financial experts to suggest an intermediate system between freely flexible exchange rates and the old IMF system of adjustable pegs. With sizable exchange-market interventions by governments and central banks, exchange rates were not freely flexible. They were being managed by the authorities. (Such a managed floating rate is sometimes called a “dirty” float.)

Some experts supported more active exchange-rate management in order to prevent currencies from becoming severely misaligned. Governments were advised to declare “target zones” for exchange rates and to buy or sell currencies whenever needed to keep exchange rates within these zones—moving the target zones as fundamental economic conditions changed. The concept was to avoid large exchange-rate swings.