Hamid Reza Imany - Department of Accounting,college of economic and management,shiraz branch, Islamic Azad University ,shiraz,iran

The purpose of this research is to study The Relationship Between Product MarketCompetition and the Cost of Equity Capital in the Companies Listed in Tehran StockExchange (TSE). Hence, an attempt will be made to answer the following question: Isthere a significant relationship between Product Market Competition and Cost of EquityCapital? . To find the answer, this research utilizes the the Herfindahl-Hirschman, Lernerand Modified Lerner indexes as proxies for product market competition. The statisticalsample of the study consists of 82 companies of the TSE during 2009 to 2014; E- viewsare used for testing hypothesis. The results suggest that there is a negetive relationshipbetween criteria of Product Market Competition (i.e. Herfindahl-Hirschman, Lerner andModified Lerner indexes) and Cost of Equity Capital.

Product Market Competiti, Cost of Equity Capital, Herfindahl-Hirschman indexes