Investigating the Impacts of the Level of Voluntary Disclosure on the Cost of Capital of the Companies Listed in Tehran Stock Exchange

To restrict undesirable investor’s perception and create more awareness about future prospects, companies make voluntary disclosure. Providing voluntary information about identification, measurement and disclosure of accounting numbers in financial statements lead to attracting investors and effectively helping to improve the company's financial situation and managerial portrait. The purpose of this research is to study the relationship between the level of voluntary disclosure and cost of capital of the companies listed in Tehran Stock Exchange. Botosan's (1997) check list which has been adjusted by Kashanipour et al. (2009) was utilized to measure voluntary disclosure level. The check list consists of 71 indices through six sections of background information, summery of historical results, key non-financial statistics, segments information, projected information and management discussion and analysis. Moreover, cost of capital variable is measured by using Gordon model. To test research hypotheses multivariate regression with panel data is utilized. The results show that there is no significant relationship between voluntary disclosure level and cost of capital of 122 listed companies of Tehran Stock Exchange during 2003-2011.