Food prices have been rising rapidly. Have we just become spoiled to low food prices or has something triggered the big jumps we're seeing at the grocery store? Listen

Dr. Mike Walden, North Carolina Cooperative Extension economist in the College of Agriculture and Life Sciences at N.C. State University, responds:

"Well, your perception is absolutely correct. Through most of this decade, food prices were going up an average of between 2 and 2 1/2 percent each year. Then in 2007, they went up 3.3 percent, and this year they are going up at an annual rate of close to 5 percent. So food prices have taken a jump. And I think two things have happened to cause this. One is that - and it's a good thing - is that the world's standard of living is rising, and more people in more countries are eating better. They are eating different kinds of foods, particularly more protein, and that is pulling up prices of basic commodities including food. Second, though is a policy choice. And we in this country have chosen to try to develop ethanol. Ethanol is a corn-based fuel. And so we are diverting a lot of our corn crop to ethanol. For example, 10 years ago only 2 percent of our corn crop was used for ethanol. Now it's up to 20 percent, and in a couple of years it will be on track to be at 30 percent. And what this does, it takes out corn from the food system, and corn is a basic feed into livestock, for example, and to dairy cows. And if you're taking that out, you're increasing the price of that feed, and those feed price increases are going to be passed on to the consumer. Now the good news out of all of this is that food is still a relatively small part of the average family's budget, taking about 15 percent of income."