A new, clever, but perhaps misleading way of studying the income profile of society, based on comparing the income of the mass of families over time, shows that under presidents Reagan and Clinton, the incomes of most individual American families rose steadily. Under Bush I, and since 2001, incomes have fallen for most families.

This is interesting, but it is the wrong way to measure how the economy is treating workers. It opens the way to an illusion comparable to the Shepard tone, in which each worker's income rises all the time, but the overall income profile of society does not change at all (or even goes down). Based on the article, it seems that this is what happened to the US economy under Reagan and Clinton: almost everyone's individual income slowly rose as the income profile of society fell.

The customary measurement of income profile is done by comparing workers of any given age group in different periods — for instance, workers of age 25 today with workers of age 25 in the 1970s, 1980s, 1990s, and 2000s. The result shows how society's treatment of people in a certain situation has changed over time. That is what matters for public policy.