The University of Michigan's Panel Survey on Income Dynamics has done exactly this, providing the longest-running record of Americans' earnings.

She is a co-principal investigator of one of the longest-running social science longitudinal surveys - Panel Study of Income Dynamics.

Mr. Conley's study is based on data from the University of Michigan's Panel Study of Income Dynamics, which has followed thousands of families since 1968.

It follows 3,725 individuals ages 16 and over who remained part of the University of Michigan's Panel Survey on Income Dynamics for a 16-year period.

Much of it is based on data collected on individuals over many years by the University of Michigan's Panel Study of Income Dynamics.

At least one company, Income Dynamics of Omaha (www.incomedynamics.com), does that research for you.

This is similar to the American Panel Study of Income Dynamics (PSID).

The line traces the year-to-year instability of family income from 1972 to 1998, based on the University of Michigan Panel Study of Income Dynamics.

But it also runs the Panel Study of Income Dynamics, a widely cited continuous survey of household finances in the United States.

Garces, Thomas, and Currie used data from the Panel Survey of Income Dynamics to review outcomes for close to 4,000 adults followed from childhood.