the relationship between the effective tax rates and the companies' characteristics

the corporate income tax rate plays a worthwhile role in developing fiscal and tax policies for companies, lawmakers and analysts. so, one of the most important issues in tax field, is to determine effective tax rates. the study and scientific calculations of the effective tax rates provide an enhanced tax justice and a careful study of tax pressure on taxpayers would be possible. the objective of this paper is, first to assess an effective tax rate and second, to study its relationship with the related industry, firm size, profitability, financial leverage, investment intensity and the structure of the ownership as the characteristics of a company. the results of this research pave the way for enacting new laws and helping tax authorities of corporate income tax. considering all companies of this research, the results indicate that the average effective tax rate is near to statuary income tax rate. however by considering a company's related industry, the results show that almost each industry has its own effective tax rate. the research has concluded that there is a negative and significant relationship between the effective tax rate from one side and firm size and profitability on the other side and there is also a positive and significant relationship between effective tax rate and financial leverage and also no relationship between effective tax rate and investment intensity and ownership structure was observed.