"If you're in Pakistan, and you go to the local market to buy wheat to hand-grind into flour to make chapati, and the price of wheat doubles, the price of your chapati basically doubles," he tells Fresh Air's Terry Gross. "They're not insulated from the doubling or tripling of world grain prices the way that we [in the United States] are. ... And this is one of the factors feeding the unrest in the Arab world, North Africa and the Middle East."
• Read more: Food: The Hidden Driver of Global Politics at NPR
Related: USDA Expects Food Prices to Rise