Influence of Development Indicators on the Tax Revenues of Iran (Cointegration Approach)

The share of taxes to total public revenues differs among countries, and the main factors that have been discussed as the cause of the difference in the tax structure are the level of development of countries that are typically represented by gross domestic product per capita, productive expertise, or the structure of the economy; external factors such as the level of foreign direct investment and trade. The amount of public debt and public policies, including exchange rates, inflation and fiscal policies, government efficiency and organizational factors, such as political stability, accountability and transparency, civil and political rights, education levels, general expenses for education, etc, are also determinants of tax revenue. The purpose of this study was to investigate the effect of development indicators on the tax revenues of Iran during the period of 1979-2017 based on the Autoregressive Distributed Lag Model (ARDL) method. Based on the results of this study, the increase of per capita GDP in the country has a positive effect on the ratio of direct taxes to GDP, but has a negative and significant effect on the ratio of indirect tax to GDP. Also, the impact of the human development index on the ratio of direct taxes and indirect taxes to GDP is positive and significantand the effect of the index of inequality of income distribution, that is the Gini coefficient, on the ratio of direct taxes and indirect taxes to GDP, was negative and significant. Finally, the effect of the combined development index on the ratio of direct taxes to GDP as well as the ratio of indirect tax to GDP has been positive and significant. Also, the country's oil revenues have a negative and significant effect on the ratio of direct taxes and indirect taxes to GDP.