There are many who point to the diversion of crops to biofuel production as a major source of rising food prices, though estimates of the actual impact of biofuels on food markets vary broadly. For example, the UN Food and Agriculture Organization (FAO) estimates that biofuels are to blame for 30 percent of food price increases, while U.S. estimates put this figure at three percent.

Others say that an amalgam of disparate ­­­­­­­­­­­­­­­­­causes have brought about high food prices. This includes speculation, rising demand in developing nations, protectionism, drought in major food-producing nations such as Australia and Canada, and rising fuel and fertilizer costs.

The debate on oil centers on whether or not recent prices reflect a ‘bubble’ caused by speculation and market manipulation. If not, then these prices may indicate a more fundamental and permanent shift brought about by rising demand in developing nations and supply-sided strains.

However, there is some evidence to suggest that the effect of speculation on prices may be limited. For instance, while the price of West Texas Intermediate (WTI) crude has more than doubled since January 2006, other traded commodities have been stable. The price of cotton futures has increased 19 percent since the start of 2006 while cattle prices are unchanged. Meanwhile, the price of Central Appalachian (CAPP) coal, which is not traded in the futures market, increased over 150 percent since January 2007.

Even if speculation is not the culprit, however, it remains unclear whether or not one should expect prices to decrease. Wheat prices, for instance, have retreated from their March 2008 peaks due to robust production growth that is expected to continue, though they remain well above historic levels. Other commodities may experience similar supply growth in response to prices, though oil producers are likely to be among the least able to respond in the short term.