Drought causing global food price spike
Economists said the U.S. isn't the only economy affected by the drought.
According to the United Nations' Monthly Food Price Index, the cost of food is surging around the world.
Corn prices are driving the increase.
The U.S. produces more corn than any other country.
Record heat over the past 12 months has killed off much of the crop.
The Agriculture Department said more than half of all U.S. countries are disaster zones.