"Let's focus on manufacturing, ... because manufacturing is where most exporting takes place," says Dr. Walden, a professor of agricultural and resource economics. "If you look at all U.S. manufactured products today that are manufactured here in our country, about 14 percent of them are exported to foreign countries. So 86 percent are sold to domestic buyers. Now this is higher –- the export side is higher than it was in the past -- but it's much lower than in other countries. And I think the simple reason is because the U.S. is such a large market.

"Now in terms of breaking that down and saying what parts of manufacturing are more export-oriented, the prize goes to computer products -- computer technology products. Twenty-one percent of those manufactured in the U.S. are exported," he says.

"Second prize goes to factory machinery: machinery that's made specifically for factories. We export about 16 percent of our factory machinery to other countries.

"Third place, and this may surprise some people, goes to manufactured food -- processed food products. We sell about 15 percent of our processed food to foreign buyers.

"And then completing the list of the top ones: transportation equipment and leather products, interestingly," he concludes. "Both sell about 13 percent of their output to foreign buyers."