Tax Progressivity and Income Inequality: A case study of a selected number of countries with natural resource rents and OECD countries

The main purpose of this article is to study the impact of progressive income tax systems on income inequality. In so doing, by using progressive tax data which were developed by Peter and Duncan (2008) three panel data model are estimated for a selected number of countries with natural resource rents and OECD countries. The findings showed that although progressive tax reduced the observed income inequality, it had a smaller impact on the real inequality which was measured by consumption-based Gini coefficient and may even increase the real inequality under specific conditions (e.g.in countries with weak law and order and a large informal nontaxable sector). Also natural resource rents and inflation are the main factors affecting inequality. Based on the result a progressive tax structure and raise the top tax rate will not necessarily reduce inequality, but also in terms of the underground economy and weak institutions, progressive tax systems may even worsen inequality, so to reduce inequality we recommend that government should pay special attention to macroeconomic stabilization and optimal management of oil revenue spending.