firm size and productivity: evidenced from new entrants in the iran's other non-metallic minerals industry during the third development plan

firm size and its impact on the firm performance examined in all of economics historical periods from different point of view. meanwhile, productivity is one the most important performance index for each firm, therefore so many studies tries to survey firm size impact on it. in iran also, economics literature replete with productivity studies but the impact of size on it rarely seen between them. thus, this study focused on other non-metallic mineral products industry as one of the most important manufacturing industries in iran to explain the size effect on productivity. dea and malmquist index have been used in order to measure productivity and pooling data method to estimate its relation with firm size. the results indicate that not only the larger firms have better performance in productivity at the 2-digit industry levels, but also we could see this result in most of 3 and 4-digit codes, too. jel classification: d24، l25، l61