Quality differentials between light/sweet and heavy/sour crudes increased dramatically both during the 1973 Arab oil embargo and the 1979–1980 Iranian political upheaval. Along with the rapid increase in crude oil quality differentials, there also emerged a widening gap between the prices of...

The Iran-Iraq war has been one of the main factors contributing to the world oil market's volatility in the last three years. Furthermore, it has helped to undermine OPEC's cohesiveness and market control, resulting in the $5 per barrel (/b) price cut in March 1983. Analysts are now divided on...