by Michael D. Stroup, Keith Hubbard
August 22, 2013
Working Paper Series
We propose a set of qualitative principles for critically evaluating any tax progressivity methodology that can produce measures of progressivity, referred to hereafter as indexes. We apply these principles to two well-established indexes (Kakwani 1977; Suits 1977) and to a more recent index (Stroup 2005). We also examine the informal method of analyzing progressivity developed by Piketty and Saez (2007). We show that the Stroup index arises from a methodology that is superior to these others, making it a more accurate and more reliable index of overall tax progressivity.