RELATIONSHIP BETWEEN OWNERSHIP CONCENTRATION AND AMOUNT OF VOLUNTARY DISCLOSURE

This article studies effect of companies’ ownership concentration on amount of voluntary disclosure of information in annual reporting of listed companies in Tehran Stock Exchange. In this research, ownership concentration is categorized in two categories of institutional and managerial ownership. The voluntary disclosure was determined by 42 indexes which had been used in the previous study by using some modification. Statistical sample of research includes 96 companies listed in Tehran Stock Exchange which published financial statement and report of board’s activity related to 18th March through 2009- 2011. In order to test research hypotheses, single-regression model has been used by SPSS software and finally a general model of multi-purpose regression was submitted. Research findings indicate a positive and significant relationship between each factor of ownership concentration (institutional and managerial) with amount of voluntary disclosure in annual reporting of listed companies in Tehran Stock Exchange.

Ownership Structure, voluntary disclosure, institutional ownership concentration, managerial ownership concentration