 However, it fell back down to the low 30s by his second term in the White House.This percentage reduction in the effective marginal income tax rate for the wealthiest Americans, 9%, is not a very large decrease in their tax burden, according to Noah, especially in comparison to the 20% drop in nominal rates from 1980 to 1981 and the 15% drop in nominal rates from 1986 to 1987.In addition to this small reduction on the income taxes of the wealthiest taxpayers in America, Noah discovered that the effective income tax burden for the bottom 20% of wage earners was 8% in 1979 and dropped to 6.4% under the Clinton Administration.