Journal of Tax Research

  Taxes after oil are the main source of government revenue. The more precise tax is predicted relying on statistics, information and tax policy reform, the better it can help policy makers to achieve economic development and growth goals accordingly, it is required to provide a scientific model to improve financial liabilities of firms in the industrial sector. The purpose of this study is to investigate the factors that influence the relative size of financial liabilities, calculated on the basis of industry market structure variables. In this study, after calculating indicators of financial market structure and relative size of firms’ tax and the monopolistic competitive industry breakdown, industries are examined in the framework of a theoretical model in the ISIC classification for the period of (1381 - 87) and by the combined data model. The findings suggest that the degree of concentration Herfindahl–Hirschmn Index ­ (HHI), the severity of barriers to entry, Minimum Efficient Scale (MES) and the ratio of investment to capital stock (M/K) based on panel data model associated with the relative size of Industrial firms’ tax, are significant.