Effect of tax policies on each household income group's share of total income, 1979 and 2007, and the difference needed in 2007 to preserve 1979 post-tax shares
* This shows the degree to which the tax system would have needed to increase 2007 pretax income shares to keep each group's share of post-tax income stable from 1979 to 2007, given the increasing inequality of pretax income over this period.
Note: Data are for comprehensive income. The changes in the difference needed in 2007 to preserve 1979 post-tax shares do not sum to zero due to the presence of negative-income households in CBO data.
Source: Authors' analysis of Congressional Budget Office (2010a and 2010b)