An Investigation of the Relationship between Ownership Concentration and Tax Aggressiveness

The main objective of this study is to investigate relationship between ownership concentration and tax aggressiveness for companies listed in Tehran Stock Exchange (TSE) from 2002 to 2011. The research question is whether the type of largest shareholder ownership (public or private)، affects tax aggressiveness or not. In this study largest shareholder ownership is used as concentration ownership measurement and effective tax rate as tax aggressiveness measurement. Lower the effective tax rate it means that firm is tax aggressive. Results of study indicate that when ownership concentration is higher، the firm is less tax aggressive. Probably this is due to the high concentration of state ownership. Social and political theory is confirmed.