Surveying the Effect of some Corporate Governance mechanisms On Firm Value with emphsize on Reporting Transparency ranking in TSE Accepted Companies

With special emphasis on reporting transparency, the present study seeks to examine the effect of some Corporate Governance mechanisms on Firm Value with emphsize on Reporting Transparency ranking in companies listed at Tehran Stock Exchange. Independent variables include some corporate governance mechanisms which, in turn, comprises independent directors, ownership concentration, institutional ownership, auditor type and free floating shares.firm value is our dependent variable measured by Tobin-Q index. adjusting variable of reporting transparency or disclosure quality, along with control variables such as firm size, leverage, and growth opportunity are used. The study is an applied research with correlative, post-event methodology. Population of the study includes 104 companies listed at Tehran Stock Exchange during 2003 to 2011 using screening method. Normal least squares regression model is used for testing hypotheses. Results indicate that from among corporate governance mechanisms in general and in companies with high level of transparency, independent directors has positive and significant, while auditor type has negative and significant, effects on firm value. In companies with low level of transparency, only independent directors have positive and significant on firm value.