Income disparities increased dramatically in the 1980s and 1990s, according to a recent Congressional Budget Office study.

From 1979 to 1997, the average after-tax income of the poorest 20 percent of households was stagnant while that of the top 1 percent skyrocketed.

The after-tax income of the bottom 20 percent fell by $100 during the 18-year period, according to figures adjusted for inflation.

After-tax income of the top 1 percent of households went up $414,200, or 157 percent. The middle fifth of households saw their after-tax income grow modestly by 10 percent, or $3,400.

–Gregory N. Heires