Assessment of the Proposal to Change the Personal Income Tax due to the Features of Khums: Computable General Equilibrium Approach

The reform of the tax system has always been a major concern for economists as well as a major challenge for policymakers. One of the main priorities of the Iranian tax system is to delve into consideration of obligatory religious payments (Khums) and charity in order to persuade people to pay taxes as well as to reduce tax burden. One of the suggestions have been offered in this field is to substitute Khums for the corresponding income taxes. Khums has a structure the same as tax on total income with a flat rate. In the present contribution, the economic effects of this suggestion were evaluated. The assessment of tax proposals is often studied by performing simulations. The present study evaluated and asserted the suggested changes in the personal income tax structure in Iran with the features of khums (rate unionization and its post-consumption) via the Dynamic Computable General Equilibrium Model and the Social Accounting Matrix 1390 (2011). The outcomes of the present study showed that the household savings have been declined over a 30-year period, while household consumption and expenses have increased at the same period of time. In other words, current consumption is preferable rather than saving for the future. In spite of increasing consumption, reduction in saving has resulted in lower investment, which ultimately it would cause a decrease in GDP.