Investigating the relationship between ownership structure and financial performance with emphasise on research and development expenditures in companies admitted to Tehran Stock Exchange

This study aims to examine the impact of ownership structure (i.e. family ownership, government ownership, and foreign ownership) on firm performance, (Tobin's Q ratio and return on assets)with emphasize on research and development in companies admitted to Tehran Stock Exchange. The required data for the six-year period from 2011 to 2016, using systematic elimination during was collected, for 129 companies from listed companies in Tehran Stock Exchange. The hypothesis testing is done using Eviews and Stata software. The results of the research show that there is a negative and significant relationship between government ownership with the Tobin's Q ratio but there is no significant relationship between family ownership and the Tobin's Q ratio. There is also a negative and significant relationship between government and foreign ownership and return on assets and there is significantly positive relationship between family ownership and return on assets. Research and development expenditures have a significant effect on the relationship between government ownership and the Tobin's Q; however, there is no significant effect on the relationship between family ownership and foreign ownership with the Tobin's Q. Also, research and development expenditures on the relationship between government ownership and family ownership does not have a significant effect on return on assets, but it has a significant effect on the relationship between foreign ownership with return on assets.