The principal objective of OPEC has been to raise the price received by the oil-exporting countries. During its early years, it was notably unsuccessful: plentiful supplies of oil kept the price low throughout the 1960s. In the early 1970s, however, major changes took place. The rapid economic expansion, which was simultaneously occurring in many countries, put upward pressure on the demand for oil. At the same time, the production of oil was leveling out and beginning to decline in the United States, with the result that U.S. demand for imported oil was rising rapidly.

In 1973 OPEC seized the opportunities offered by the changing market conditions—and by the political and economic disruptions associated with the war between Israel and its Arab neighbours—to raise prices sharply, from about $3 to more than $12 per barrel. Between 1974 and 1979 the international price of oil remained quite stable, but then OPEC was once again successful in pushing the price up sharply—to more than $30 per barrel in 1980. These price increases caused a huge transfer in revenues from the oil-importing nations to the oil-exporting countries. They also contributed to a major increase in inflation in the importing countries.

The large increase in revenues in the OPEC nations allowed many of them to embark on major development programs. On the other side, the loss of revenues, combined with the inflationary impact, precipitated major recessions in many of the oil-importing countries in 1974–75 and 1980–82. The higher oil price also has been suggested as a cause of a decline in productivity in many countries after 1973, although the causes of the decline are not well understood.

OPEC has often been called an international cartel, but it lacked the standard enforcement mechanism of a cartel during the two periods (1973 and 1979–80) when prices rose spectacularly. That is, it did not have a mechanism for sharing the market among the oil-exporting nations. Saudi Arabia played a key role in enforcing the organization’s price increases.

In the 1970s Saudi Arabia had proven reserves in excess of 150 billion barrels, more than twice as much as any other nation, and five or six times the proven reserves of such major non-OPEC producers as the United States and Mexico. Because of its huge reserves and productive capacity, Saudi Arabia was able to act as the residual supplier, cutting back on production when demand slackened, thus reducing downward pressures on prices. Saudi Arabia’s willingness to act as the residual supplier was partly the result of its limited population; even when producing at much less than capacity, it had a very large oil income per capita.

During the early and middle 1980s, the oil market softened markedly. Oil consumption grew much more slowly, partly as a result of the major U.S. recession of 1982 and sluggish growth in western Europe, and partly as a result of increased conservation measures, a reaction to the upward spiral of fuel prices in the 1970s. At the same time, oil output increased in a number of non-OPEC areas such as the North Sea.

The result was downward pressure on prices through the mid-1980s. In order to maintain sales and revenues, OPEC members had an incentive to undercut the posted price. As its oil production fell sharply and the bills from its ambitious development projects continued to increase, Saudi Arabia became less willing to act as the residual supplier. In order to relieve the downward pressure on prices, OPEC members attempted to transform the organization into a more formal cartel, with production quotas for each member. However, these efforts faced the classic problem of cartels: each member had an incentive to cheat on the organization by producing more than its quota and by offering secret price concessions to buyers.