A U.S. Department of Agriculture Economic Research Service report, Factors Behind the Global Rise in Rice Prices in 2008, attributes the sharp increase in rice prices last year to trade restrictions imposed by major suppliers, panic buying by several large importers, a weak dollar, and record oil prices among other causes.

While rice prices have declined from historic highs, they remain well above pre-2007 levels, the report says.

Despite export restrictions by other major rice supplying countries, the United States did not restrict rice exports and remained a reliable supplier.