摘要：After tax income and consumption of each income class are cointegrated respectively, we can estimate an ideal before tax consumption from the Permanent Income Hypothesis point of view. In this paper, with this estimated before tax consumption, we calculate the before tax version of the economic inequality measure proposed by Fukushige (1989), and evaluate the tax progressivity by their rate of change from the before tax version to the after tax version. This index has several theoretical advantages. Also its empirical application to Japanese data makes its advantages clear.
