On a macro level, supply and demand. Alternative sources that can deliver volume keep prices down. Oil is bouncing around $75 rather than way over $100. Is it coincidence that the Saudis have the Cartel price down around the minimum economic price for tar sands oil? Don't forget the premium speculators threw in for political instability in the Middle East.
Actually the Saudi's were considering a price war in an attempt to drive oil price below the economic price level required for new US Fracking wells. If they do, we could see $2.00 gas again. In such a scenario we could hear the Ruskies and Iranian's squealing all the way over here.
