All three measures of hourly wage inequality from the CPS MORG display large increases in the first part of the 1980s, but in contrast to the March CPS FTFY series, residual inequality stopped growing after the mid-1980s for hourly wages in the CPS MORG.
We use the Integrated Public Use Micro-samples from the 1940-70 decennial censuses (Census IPUMS) to extend our March CPS series on overall male FTFY weekly wage inequality (from the top panel of figure 2) back to 1939.
The smoothed trend lines are clearly different, however, with the FTFY workers in both the CPS and LSY79 samples now showing a weak positive trend.
Excluding the self-employed, the pattern obtained is basically the same as that of the full sample of FTFY workers: in the final specification of model C, both samples again show a positive trend of similar magnitude in earnings dispersion over time.
11) The trends for FTFY workers look similar for the two samples--that is, both groups show a modest upward trend.
The plot for FTFY workers, not shown here, looks much like the plot for all workers, without the greater relative density in the lower tail of the CPS.
Modeling the cohort dependence in the NLSY79 changes the estimates of the dispersion trend, especially when the sample is restricted to FTFY workers.