Investigating the Impacts of Voluntary Disclosure Level on the Information Asymmetry of the Companies Listed in Tehran Stock Exchange

Managers venture to voluntary disclosure to inform investors about firms’ future point of views, goals and strategies. Financial and non-financial voluntary information reduce information asymmetry, increase stock liquidity and improve financial stability. In this research the relation of voluntary disclosure level and information asymmetry of listed companies of Tehran Stock Exchange is investigated. Botosan (1997) check list which has been adjusted by kashanipour and et al. (2009) was utilized to measure voluntary disclosure level. The check list consists of 71 indices through six section of background information, the summery of historical results, Key Non-Financial Statistics, Segments Information, Projected Information and Management Discussion and Analysis. Moreover, information asymmetry variable is measured by using Venkatash and Chiang (1986) model. To test research hypotheses multivariate regression with panel data is utilized. The results show that there is no significant relation between voluntary disclosure level and information asymmetry of 122 listed companies of Tehran Stock Exchange during 2003-2011.