"Because this change in diet has been slow and incremental, it cannot explain the dramatic price movements of the past year. The second change can: the rampant

"Because this change in diet has been slow and incremental, it cannot explain the dramatic price movements of the past year. The second change can: the rampant demand for ethanol as fuel for American cars. In 2000 around 15m tonnes of America's maize crop was turned into ethanol; this year the quantity is likely to be around 85m tonnes. Ethanol is the dominant reason for this year's increase in grain prices. It accounts for the rise in the price of maize because the federal government has in practice waded into the market to mop up about one-third of America's corn harvest. A big expansion of the ethanol programme in 2005 explains why maize prices started rising in the first place."