The Impact of Board of Director Size and Managing Director Duality on Market Value of Firms: Evidences from Tehran Stock Exchange

More than everything, corporate governance focuses on the safe long-term life of firm and can cause to developing value and efficiency of firm. So, this research investigates the effect of board of director size and managing director duality on value of accepted firms in Tehran stock exchange. Thus, we select a 700 year-firm sample during 2006-2010 for examining the hypotheses of research. The Results showed that there is no significant relationship between the number of board of directors and market value of firms. Also, research results showed that there is positive and significant relationship between managing director duality and market value of firm. Furthermore, the results of control variable test showed that there is positive and significant relationship between the variables of Tobin’s Q ratio and asset efficiency ratio with market value ratio. But we don’t observe significant relationship between firms’ size and Tobin’s Q ratio.