Crude oil prices behave much as any other commodity with wide price swings in times of shortage or oversupply. The crude oil price cycle may extend over several years responding to changes in demand as well as OPEC and non-OPEC supply. 

The U.S. petroleum industry's price has been heavily regulated through production or price controls throughout much of the twentieth century. In the post World War II era U.S. oil prices at the wellhead averaged $24.98 per barrel adjusted for inflation to 2007 dollars. In the absence of price controls the U.S. price would have tracked the world price averaging $27.00. Over the same post war period the median for the domestic and the adjusted world price of crude oil was $19.04 in 2007 prices. That means that only fifty percent of the time from 1947 to 2007 have oil prices exceeded $19.04 per barrel.  (See note in box on right.)

Until the March 28, 2000 adoption of the $22-$28 price band for the OPEC basket of crude, oil prices only exceeded $24.00 per barrel in response to war or conflict in the Middle East. With limited spare production capacity OPEC abandoned its price band in 2005 and was powerless to stem a surge in oil prices which was reminiscent of the late 1970s.

OPEC was formed in 1960 with five founding members Iran, Iraq, Kuwait, Saudi Arabia and Venezuela.  Two of the representatives at the initial meetings had studied the the Texas Railroad Commission's methods of influencing price through limitations on production. By the end of 1971 six other nations had joined the group: Qatar, Indonesia, Libya, United Arab Emirates, Algeria and Nigeria.  From the foundation of the Organization of Petroleum Exporting Countries through 1972 member countries experienced steady decline in the purchasing power of a barrel of oil. 

Throughout the post war period exporting countries found increasing demand for their crude oil but a 40% decline in the purchasing power of a barrel of oil.  In March 1971, the balance of power shifted.  That month the Texas Railroad Commission set proration at 100 percent for the first time.  This meant that Texas producers were no longer limited in the amount of oil that they could produce.  More importantly, it meant that the power to control crude oil prices shifted from the United States (Texas, Oklahoma and Louisiana) to OPEC.  Another way to say it is that there was no more spare capacity and therefore no tool to put an upper limit on prices. A little over two years later OPEC would, through the unintended consequence of war, get a glimpse at the extent of its power to influence prices.