"This actually becomes I think more important as people move into retirement because when people stop working they become more sensitive to how their income is changing," says Dr. Walden, a professor at N.C. State University. "But anyway ... there are really two standards that you can apply to the phrase ... keeping up with the Joneses.

"One is the inflation standard. And this says that you want your income each year to keep up with inflation, or the rising cost of living," he adds. "So recently that would mean you would want to have your income going up by 2 or 3 percent.

"The second standard we will call the real growth standard, and this recognizes that on average the average person's income -- especially those folks who are working -- actually goes up faster than inflation. It may be going up 4 or 5 percent a year," he continues. "And so if you want to keep up with how the standard of living of the average person is changing, you need to have a bigger increase in your income.

"So what this sets up is a potential problem, especially for retired folks because oftentimes retired folks only see their income going up with inflation. If they actually realize that the average person's income is going up faster than inflation, they may feel like they are falling behind."