Have opec nations increased the price that they charge for oil in the last few years?

and how do you know that? ?please help??? thanks Have opec nations increased the price that they charge for oil in the last few years?
Yes- they get together and make agreements to control output in order to manipulate the price. - But they don't want to push the price up as high a possible .They want to set a price which makes them the most money. If they push the price up too high, people would start buying much more gas efficient cars. Then demand would drop and OPEC wouldl sell a lot less oil. The price has to be kept just low enough so that people don't start conserving energy by buying gas efficient cars, driving less, and using public transportation. Five dollar per gallon gas in the U.S. would be bad for OPEC.Have opec nations increased the price that they charge for oil in the last few years?
They manipulate the price by increasing/decreasing the supply of oil. They're doing it now, turn on the news. They are decreasing the supply because the cost per barrel is falling. They want to decrease supply in order to drive up demand and price.