Impact of Conservatism and Disclosure Quality on Cost of Equity Capital

Conservatism and disclosure quality reduce information asymmetry, uncertainty and cost of equity capital. Thus, we expect an inverse relation between conservatism and cost of equity capital. Further, we expect that the strength of this relation is diminished for firms in the highest information environment.
To do this, we use a sample of 84 listed companies at Tehran Stock Exchange (TSE) over an eight years period (2003-2010). In this study, we use the Givoly and Hayn (2000) measure and the market-to-book ratio (Beaver and Ryan, 2000) as proxies for conservatism, and disclosure ratings data published in the Securities and Exchange Organization reports as a proxy for firm disclosure quality. Further, we use the Easton (2004) PEG measure, Capital Asset Pricing Model and the one year ahead forecast of accounting earnings per share-to-price per share ratio as cost of equity capital estimates.
The results indicate that there is an inverse relation between firm level conservatism and the cost of equity capital, but that this relation is diminished in environments of high disclosure quality. Furthermore, the results show that the market-to-book ratio (Beaver and Ryan, 2000) and the Easton (2004) measure have a much higher ability to estimate the research models.