A few years ago the “food versus fuel” debate raged in Washington. It centred on whether the US government’s corn ethanol mandate squeezed scarce grain supplies and pushed up food prices. Yet last week, corn dropped to $3.01 a bushel, a level last consistently seen before lawmakers enacted the mandate in 2007. Supermarkets will raise food prices less than 1 per cent this year, well below the historical average, according to the USDA. The UN’s international food price index is also lower than in 2007.