EVALUATING THE RELATIONSHIP BETWEEN CORPORATE GOVERNANCE AND VOLUNTARY DISCLOSURE IN COMPANIES LISTED IN TEHRAN STOCK EXCHANGE

An improved and enriched disclosure of information, especially voluntary information peculiar to a company, is an important and effective feature and mechanism in economic decisions of capital investors and also a favorable feature of competitive marketing. Voluntary disclosure of information along with obligatory information, allows quick transactions with low costs without severe effects on prices which is a major determinant in viability of markets, Tehran stock exchange included. The present study evaluated the effects of mechanisms of corporate governance on voluntary disclosure of information in companies listed at Tehran stock exchange in a period of eight years from 1381 to 1388. Independent variables used here are corporate governance mechanisms including indirect directors (ID), ownership centralization (OC), institutional ownership (IO), free float (FF), and auditor type (AT). The dependent variable is voluntary disclosure (VD) of information in companies which is obtained, according to Jensen index, by the ratio of voluntary disclosure of corporate information divided by total amount of voluntary disclosure (62 cases). Control variables include corporate value, obtained from natural logarithm of sales, and financial leverage which is obtained by longterm debts divided by total assets at the end of each financial year. Overall, results indicate that there is a significant relation between indirect directors and institutional ownership with voluntary disclosure of information, but no significant relation was observed during the study for the three mechanisms of corporate governance, namely ownership centralization, free float, and auditor type, with voluntary disclosure of information.