Evaluating the Most Important Factors Effecting Direct Taxes in Iranian Economy with TVP-DMA and TVP-FAVAR Models Approach

The importance of taxes in financing the state budget and exploiting it in the implementation of fiscal policies aimed at redistribution of wealth and income as well as optimal allocation of economic resources among different sectors has revealed more and more the need for identifying the key factors affecting the tax revenues and examining how they affect. In this study, while investigating the factors affecting the direct taxes and their related theoretical basics in the Iranian economy, selecting the important variables affecting the direct taxes of Iranian economy during the period 1972-2018 using dynamic TVP-DMA models was considered. After selecting the important variables affecting the direct taxes through the estimations made by the model, the instantaneous reaction functions or reactions resulting from the changes of these variables and their effects on the growth of the direct taxes in the aforementioned time periods using TVP-FAVAR models were also investigated. The results of this research based on the outputs of TVP-DMA and TVP-DMS models show that in Iranian economy, the variables of “openness degree of economy”, “growth of development budget”, “inflation”, “average tax rate”, and “real income growth” are respectively the most important variables affecting the growth of direct taxes. Examining the effects of these variables on the development of the direct taxes during the study period shows that the openness degree of economy, growth of development budget, average tax rate in the sector of direct taxes, and real income growth have had a positive effect on the growth of direct taxes over many years. The impact of inflation on the growth of the direct taxes in the Iranian economy has been changing over the period, and it has been positive for some years and negative for other periods. Therefore, based on the results of the model, the question of whether the impact of inflation on the growth of direct taxes in the Iranian economy is positive or negative cannot be answered, because the simultaneousness of the inflation and other economic (growth and unemployment rates, etc.) and tax developments (tax breaks, rate changes, etc.) is the main determinant of how this variable affects the growth of direct taxes