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

"Well, actually the numbers are a little better today. It's closer to 80 percent, but still less. But the problem with that number and these kinds of comparisons is that they are truly apples and oranges comparisons because they don't account for the fact that men and women have different kinds of jobs, based on different levels of education, experience, etc. And one reason, however, why the percentage of male salary that women earn has gone up is because women have gotten higher levels of education. But if you would actually compare men and women in exactly the same jobs where those workers - male workers and female workers - have exactly the same characteristics, average pay is actually very, very close. However, there is one factor that economists have widely pointed out that may hold women back. And that is the fact that many women take time off from their job for childbearing. It's something men can't do, physically. Women do have to take time off to have the child and perhaps a few weeks afterward. And in some jobs, not all, but in some jobs that can actually impose a cost to them on the job where, for example, if they take a couple of weeks off they may lose contact with clients or time on important projects, etc. So that is one biological factor that will probably in many jobs will keep women's pay somewhat under male pay."