The simplest argument for the oil price decline is for once correct. A wave of new U.S. fracking oil could be seen to be overtaking the modestly growing global oil demand. It became clear that OPEC, mainly Saudi Arabia, must cut back production if the price were to stay around $100 a barrel, which many, including me, believe is necessary to justify continued heavy spending to find traditional oil. The Saudis declined to pull back their production and the oil market entered into glut mode, in which storage is full and production continues above demand. Under glut conditions, oil (and natural gas) is uniquely sensitive to declines toward marginal cost (ignoring sunk costs), which can approach a few dollars a barrel — the cost of just pumping the oil. Oil demand is notoriously insensitive to price in the short term but cumulatively and substantially sensitive as a few years […]