Data based on following actual flesh-and-blood individuals over time are, however, also available. The statistics quoted above are from the Treasury Department, which has people's income tax returns, so it is no problem for them to follow the same people over the years.

You can check out the numbers for yourself in a November 13, 2007 report from the Treasury Department titled "Income Mobility in the United States from 1996 to 2005." You can find a summary of the same data in a Wall Street Journal editorial that same day.

These are not the only data that tell a diametrically opposite story from the usual political and media story that the rich are getting richer and the poor are getting poorer.

A previous Treasury Department study showed similar patterns in individual income changes between 1979 and 1988.

Moreover, a study conducted at the University of Michigan, following the same individuals over an even longer span of time, likewise found most people moving from income bracket to income bracket over time -- especially among those who began in the bottom 20 percent.

The University of Michigan Panel Survey on Income Dynamics showed that, among people who were in the bottom 20 percent income bracket in 1975, only 5 percent were still in that category in 1991. Nearly six times as many of them were now in the top 20 percent in 1991.

There was a summary of the University of Michigan data in the 1995 annual report of the Federal Reserve Bank of Dallas, which also issued an excerpt titled "By Our Own Bootstraps."

Among the intelligentsia, it is fashionable to sneer at income mobility as a "Horatio Alger myth" -- and, as someone once said, you cannot refute a sneer. But, among people who have not yet abandoned facts for rhetoric, it is worth stopping to consider whether they are being played for fools by politicians and much of the media.