Redistributive Effects of Income Tax Rates and Tax Base 1984-2009: Evidence from Japanese Tax Reforms

The primary objective of this paper is to examine how and to what extent changes in income tax rates and income tax deductions affect income inequality from longitudinal perspectives, by using microdata from Japanese individuals and households. The findings of this paper could shed light on the effects of tax rates and tax deduction on tax progressivity. First, redistributive effects of the Japanese income tax are likely to decline for the period 1984-2009. Second, the income tax reforms, i.e., reduction in tax rates and increase in tax base, give rise to greater redistributive effects of income tax rates and lower redistributive effects of tax base. Third, progressivity measures show the same trends with respect to the redistributive effects of tax changes on pretax income over the period.