This paper aims to examine the relationship between the structural and performance variables in 140 Iranian industries. besides investigating structure of industrial markets according to the Four-firm concentration ratio plus cost advantage ratio (CDR). Then the study estimates efficiency level of the industries under the stochastic frontier technique in 4 digits ISIC code so that fin... https://www.countryscenesaddleryandpetsuppliers.shop/product-category/endurance-fender/