This is the front cover of a new
Congressional Budget Office Report. Yes - over the last three decades four-fifths of earners in America have experienced significant declines in their relative share of national household income. This is after taxes, transfers, tax credits, etc. - so it reflects any intervening social policies that attempt modest redistribution.
Note that the relative declines in share are most extreme at the bottom 20% - the working poor - which started with a very small share.
What's even more revealing is the following graph, which relates to the top 1%.
Growth in Real After-Tax Income from 1979 to 2007
This second graph shows where most of the unequal re-distribution has gone. Increases in economic productivity tracked over thirty years have been skewed radically toward the very top - the "1%" - showing that even the upper quintile where an increase in the share of wealth has taken place, the distribution is radically to the upper-most economic elite even among the wealthiest Americans.
These statistics are becoming as redundant as they are rampant...but they still hold power as the country learns more and more about itself in the realm of radical income inequality.
