the relationship between the power of competition in markets and tax avoidance: evidences from tehran stock exchange

The aim of the present research is to study the relationship between the powerof competition in markets and tax avoidance in companies which are accepted intehran stock exchange. in order to evaluate the power of competition in marketstwo variables are used, namely, herfindal-hirechman indexand entrance obstacles.dependent variables in this paper are effective tax rate and adjusted nontaxableincome. the research samples are 72 companies within the period 2006 to2014. to evaluate research hypotheses, multi-variable regression is used. the researchfindings reveal that there is a negative relation between herfindal-hirechman index and the ratio of entrance obstacles from one side and effectivetax rate from the other side; so, the higher the power of competition in a companyis, the more is the tax avoidance. also, there is a meaningful difference betweenherfindal-hirechman index and adjusted nontaxable income. finally, there are notany meaningful differences between tax obstacles and adjusted nontaxable income.

The Relationship between the Power of Competition in Markets and Tax Avoidance: Evidences from Tehran Stock Exchange

The aim of the present research is to study the relationship between the powerof competition in markets and tax avoidance in companies which are accepted inTehran stock exchange. In order to evaluate the power of competition in marketstwo variables are used, namely, Herfindal-Hirechman Indexand entrance obstacles.Dependent variables in this paper are effective tax rate and adjusted nontaxableincome. The research samples are 72 companies within the period 2006 to2014. To evaluate research hypotheses, multi-variable regression is used. The researchfindings reveal that there is a negative relation between Herfindal-Hirechman Index and the Ratio of entrance obstacles from one side and effectivetax rate from the other side; so, the higher the power of competition in a companyis, the more is the tax avoidance. Also, there is a meaningful difference betweenHerfindal-Hirechman Index and adjusted nontaxable income. Finally, there are notany meaningful differences between tax obstacles and adjusted nontaxable income.