This study reports of the relationship disclosure and Accounting-based performance and Market-based performance before and after important changes in economic and accounting regulation.
The so far studies ،reveal a dual relationship between disclosure quality and firm performance. While some studies have examined the effects of level of disclosure on firm performance ،other studies have examined the effects of firm performance on level of disclosure. Reviewing the evidence of the validity of both approaches means that there is a bilateral (two-sided) relationship between these two variables. In this regard ،the goal of present research is to study the bilateral relationship between level of disclosure and performance of 66 companies listed on Tehran Stock Exchange (TSE) during 1998 to 2000 and 2008 to 2013.then simultaneous equations system was estimated using two-step regression. Based on the results ،there is bilateral relationship between level of disclosure and Accounting-based performance and Market-based performance of the companies listed on the TSE before and after Iimportant Changes in Economic and Accounting regulation.also increase relationship between level of disclosure and performance after Iimportant Changes in Economic and Accounting regulation.