The Study of Effect of Ownership Structure on Information Content of Earnings in Tehran Stock Exchange.

In this paper we provide evidence on the monitoring role of institutional investors from the point of view, whether institutional investment affects informative of reported accounting earnings of companies in Tehran Stock Exchange. In order to measure informative of earnings, three models that evaluate different aspects of informative, have been estimated; so that affect of changes in accounting earnings, earnings to price ratio and earnings to book value ratio on stock returns have been considered as informative of accounting earnings. The population includes the top 100 companies in Tehran Stock Exchange from (1378-1383), with respect to their returns, and the sample includes 39 companies. Related models have been tested by multivariate and single regression moles. The results of overall test of models of research show that the role of institutional investor's ownership has no affect on informative of accounting earnings and the most influencing variables on returns are earnings to price ratio, earnings to book value ratio and changes in earnings. The results also show positive and significant affect of ownership and concentration of institutional investors, separately, on returns.