Presenting a Parametric Model to Estimate the Structure of Iranian Industry and Determining the Position of Knowledge Base Companies for Economic Policies. Case study: Knowledge Based Companies located in Science and Technology Parks of Semnan Province.

The main objective of this study is to provide a model for Iranian industry structure estimation and determine the position of knowledge - based firms located in Science and Technology Parks of Semnan province. Researchers use concentration ratio indicators to estimate industry structure. This ratio represents the market share of some of the largest firms within an industry. For this purpose, first using the micro-data of Iranchr(chr('39')39chr('39'))s industrial sector in 2016 and using the lognormal model, the concentration ratio of 5 firms by two-digit industry codes (ISIC) was estimated and then the position of knowledge-based companies in Semnan province in this structure was determined. As a result of this research the Tobacco and Cigarette industry was monopolized industry. The number of industries active in the oligopoly structure is 5 industries, including "production of beverages", "production of coking coal and oil refining products", "production of other means of transportation", "production of textiles", "repair and installation of machinery and equipment". Also, 18 industries have a concentration ratio below 40%, among which the structure of 12 industries was classified as monopolistic competition and 6 industries as fully competitive. In base of researcher’s observations, 51 knowledge base enterprise have activated in Semnan Science and Technology Parks that have been specified their market structure by researcher separately. As a result of this research, 34 company have had monopolistic competition, 15 company have had perfect competition and 2 company have had oligopoly market structure. Finally express some offer about this research.