The structure of the world oil market is set to be oligopolistic as the oil market is dominated buy few suppliers, such as Opec and Opec + and the North Sea. For a industry to be classified as an oligopolistic industry it has to have a few large firm which hold a very large amount of output, also the firms must be interdependent, in addition the barriers to entry are very high, because not every country can produce oil, and therefore can not enter the oil market, and take advantage of the abnormal profit.
Before 1970 the world oil market was at a steady position, as the demand was inelastic, indicating that there wasn't a high demand for oil, which means that the price for oil didn't change at a significant rate, actually " the price of oil fell from approximately $1.70 a barrel in 1950 to $1.30" (Alain Anderton)
However after 1970 people realised that oil is a very efficient and cheap source of fuel, which than lead to the revolution, and demand became elastic and price for oil began to increase "By 1973 the price of a barrel of oil had risen to approximately $3.00" (Alain Anderton) As a result before 1970 there was excessive supply for oil, but after 1970 their was excessive demand, which pressurised the middle east countries to produce more oil, which lead to increase the rate that oil was being consumed.
As Opec holds a 38% of oil market shares, they tend to have a lot of oilgopolistic power in the oil industry, they can under power many non-Opec countries like America (U.S.A) who are the biggest oil consumers in the world. This can be explained by the amount of money America spend on fighting jet planes and many other different types of war arsenals. We can see the rate of oil