Abstract

This paper examines the Effect of capital structure on firm performance due to product market competition on firms listed in Tehran stock exchange deals. To achieve this goal using new indicators of competition called the Boone indicator, Herfindahl-Hirschman Index, a measure of Lerner and Adjusted Lerner competition , the Effect of capital structure on firm performance is investigated. The research sample consisted of 19 Participate in the period 9313-9311.Statistical method for testing hypotheses in the present study is "panel data".Research findings show that using the Herfindahl -Hirschman index & Boone indicator As the criteria for measuring product market competition,a significant positive relationship between capital structure and Firm performance exist. But Lerner and the Lerner index adjusted by using such a relationship was not observed. Also, the index of product market competition based on the Herfindahl-Hirschman Index or Lerner or Adjusted Lerner to be considered, Measure the Effect of capital structure on product market competition increases the performance