Value relevance of voluntary disclosure in capital market of IRAN

companies’ Voluntary disclosure is one of the most important management tools to convey information about the financial performance to investors, creditors and other stakeholders. One of the important reasons of the request for disclosure of information is agency problem and asymmetry of information. This study aims to examine value relevance of voluntary disclosure using models of Olson (1995), Easton and Harris (1991) and the value of firms with regard to the effect of endogeneity of voluntary disclosure variable. for this purpose, The voluntary disclosure index was calculated and tested for 146 companies listed in Tehran Stock Exchange during the period 1388-1392 Using content analysis method and the same weighting approach. The results of this research reveal that companies’ voluntary disclosure used in their decision-making and valuation of companies. The results from the study of non-linearity in the relation between voluntary disclosure and firm value confirm the positive significant effect of enhanced voluntary disclosure levels on the value of firms.