investigating the structural changes of tax in iran

s tructural change is defined as a change in the relative weight of the important constituents of the macro-economic indicator such as production, taxes, imports and exports, workforce etc. since the structure change is one of the main reasons for the growth and economic development of countries, the investigation of the trend of changes in economic important constituents is important. tax as an important source of state revenue is one of the most significant macro-economic indicators; furthermore it is the most important instrument of the state’s fiscal policy. so due to the important position of tax in the countries’ economy, evaluating the trend of changes in the tax structure is of paramount importance. therefore, the purpose of this study is to investigate the structural changes of taxes in iran, by bai and perron method, for the period 1971-2012. the results based on the udmax and wdmax tests show that there is at least one breakpoint in the movement process of all taxes in iran; also based on the sequential procedure all breaks have not lead to the structural changes and iran have not had the structure changes in income tax.