Harvard economist Martin Feldstein explains in yesterday's WSJ that the relationship between future and current spot oil prices (see equation above) implies that an expected change in the future price of oil will have an immediate impact on the current spot price of oil.
When oil producers concluded that the demand for oil in China and some other countries will grow more rapidly in future years than they had previously expected, they inferred that the future price of oil would be higher than they had previously believed. They responded by reducing supply and raising the spot price enough to bring the expected price rise back to its initial rate.
Hence, with no change in the current demand for oil, the expectation of a greater future demand and a higher future price caused the current price to rise. Similarly, credible reports about the future decline of oil production in Russia and in Mexico implied a higher future global price of oil – and that also required an increase in the current oil price to maintain the initial expected rate of increase in the price of oil.
Once this relation is understood, it is easy to see how news stories, rumors and industry reports can cause substantial fluctuations in current prices – all without anything happening to current demand or supply.
Also note that the spot price of oil will fluctuate even without speculators playing a role. After all, speculators have no control over the global supply of, or global demand for, physical barrels of oil. Speculators respond to market conditions, they don't create market conditions.
Now here is the good news. Any policy that causes the expected future oil price to fall can cause the current price to fall, or to rise less than it would otherwise do. In other words, it is possible to bring down today's price of oil with policies that will have their physical impact on oil demand or supply only in the future.Increasing the expected future supply of oil would reduce today's price. Any steps that can be taken now to increase the future supply of oil, or reduce the future demand for oil in the U.S. or elsewhere, can therefore lead both to lower prices and increased consumption today.