Concentration in the Iranian Cement Industry

This paper studies the degree of concentration and market power in the Iranian cement industry over the period 1380-1387. To that end، different concentration indices such as the reciprocal of the number of firms، –firm concentration ratio، Herfindahl – Hirschman، Hannah – key، Entropy، concentration curve، Gini، Lorenz curve، and variance of logarithms of firms’ size are used. While the results based on the relative measures of concentration show that the degree of concentration and market power in the Iranian cement industry has increased، the results using the absolute measures of concentration provide an opposite result. That is، despite an increase in the inequality of the firms in the cement industry، the concentration and market power has declined due to increase in the number of cement producing firms.