The Tax Foundation has updated its annual summary of the latest federal income tax data given that the IRS has released the percentile data early this year (July as opposed to September). The basic story that comes from this newly available data for tax year 2006 is that the share of income (as measured by AGI) and the share of taxes paid by the top 1 percent of tax returns are once again at all-time highs. In 2006, the top 1 percent of tax returns paid 39.9 percent of all federal individual income taxes and earned 22.1 percent of adjusted gross income, both of which are significantly higher than 2004 when the top 1 percent earned 19 percent of adjusted gross income (AGI) and paid 36.9 percent of federal individual income taxes. In 1990, those figures were 14 percent and 25.1 percent, respectively. The latest summary of IRS data is available here: http://www.taxfoundation.org/legacy/show/250.html By one measure of tax progressivity (the ratio of taxes paid to income earned for the top 1 percent of tax returns), progressivity has declined since 1993, but remained relatively unchanged since 2000 and since 1990. Note that under a pure flat tax (on AGI), the ratio would be 1. The higher the number, the greater the progressivity. Tax Year Ratio of Tax Share to AGI Share 1990 1.795 1991 1.911 1992 1.935 1993 2.104 1994 2.091 1995 2.073 1996 2.014 1997 1.909 1998 1.881 1999 1.854 2000 1.798 2001 1.933 2002 2.091 2003 2.044 2004 1.942 2005 1.858 2006 1.808
