U.S. gas station during the 1970s oil price shock.

By the early 1960s, the U.S. dollar's fixed value against gold, under the Bretton Woods system of fixed exchange rates, was seen as overvalued. A sizable increase in domestic spending on President Lyndon Johnson's Great Society programs and a rise in military spending caused by the Vietnam War gradually worsened the overvaluation of the dollar.

End of Bretton Woods system

The system dissolved between 1968 and 1973. In August 1971, U.S. President Richard Nixon announced the "temporary" suspension of the dollar's convertibility into gold. While the dollar had struggled throughout most of the 1960s within the parity established at Bretton Woods, this crisis marked the breakdown of the system. An attempt to revive the fixed exchange rates failed, and by March 1973 the major currencies began to float against each other.

Since the collapse of the Bretton Woods system, IMF members have been free to choose any form of exchange arrangement they wish (except pegging their currency to gold): allowing the currency to float freely, pegging it to another currency or a basket of currencies, adopting the currency of another country, participating in a currency bloc, or forming part of a monetary union.

Oil shocks

Many feared that the collapse of the Bretton Woods system would bring the period of rapid growth to an end. In fact, the transition to floating exchange rates was relatively smooth, and it was certainly timely: flexible exchange rates made it easier for economies to adjust to more expensive oil, when the price suddenly started going up in October 1973. Floating rates have facilitated adjustments to external shocks ever since.

The IMF responded to the challenges created by the oil price shocks of the 1970s by adapting its lending instruments. To help oil importers deal with anticipated current account deficits and inflation in the face of higher oil prices, it set up the first of two oil facilities.

Helping poor countries

From the mid-1970s, the IMF sought to respond to the balance of payments difficulties confronting many of the world's poorest countries by providing concessional financing through what was known as the Trust Fund. In March 1986, the IMF created a new concessional loan program called the Structural Adjustment Facility. The SAF was succeeded by the Enhanced Structural Adjustment Facility in December 1987.