Test of the Free Cash Flow Theory andCreditors Monitoring by Using the Three-Stage Least Squares System: Case Study of Listed Companies in Tehran Stock Exchange

The aim of this paper is to investigate the Determinants of Working Capital Management (WCM) in Tehran Stock Exchange. In this research، to measure WCM، as the dependent variable، we use Cash Conversion Cycle (CCC) and Independent variables of research are Debt ratio، ROA، Investment in fixed assets and Cash Flow. For this purpose 600 firms are considered as sample of research and using Multivariate regression model and panel data method have been tested. The result shows that there is a significant negative relationship between WCM and Debt ratio، ROA، Investment in fixed assets and there is a significant positive relationship between WCM and Cash Flow.