رThe Investigation of Mediating Effect of Costs of Research and Development Disclosure on the Relationship between Product Market Competition and Stock Returns

This study aims to examine the mediating effect of costs of research and development disclosure on the relationship between product market competition and stock returns of listed companies on Tehran Stock Exchange. We collected data from financial statements and the reports of the company’s board of directors a sample of 97 listed companies during 1389-1393. We used an adjusted Check List for measuring R&D, and adjusted Lerner Index was utilized for measuring product market competition. The results indicate that product market competition is associated with research and development disclosure. In addition, the findings show that product market competition is significantly related to stock returns. More importantly, the finding shows the cost of research and development disclosure (R&D) has mediating effect on the relationship between research and development disclosure and stock returns. This finding means that the more product market competition, however, disclose the cost of research and development (R&D) and return on equity will be more. Furthermore, the disclosure of the cost of research and development (R&D) is significantly and positively associated with stock returns.