فصلنامه بورس اوراق بهادار
پیاپی 7 (پاییز 1388)

This study is aimed to determine the role of ownership structure on firm performance. Using panel data regression analysis method, the role of variables of ownership structure which includes: ownership concentration, institutional ownership and institutional ownership concentration have been examined for 137 listed firms of Tehran stock exchange within the period 1380 to 1385. It is concluded that ownership concentration doesn’t have any significant effect on firm performance but the effect of two other variables are significant: institutional ownership has positive significant effect on firm performance but the effect of concentrated institutional ownership is negative. In the next part of this research the effect of ownership structure on firm performance based on type of the industry has been studied and it is concluded that the industry factor moderates this effectiveness relationship. The findings of this research shed light on the role of ownership structure plays in corporate performance and thus offer insights to policy makers interested in improving corporate governance system.

This study investigates whether and how a firm’s cost of equity capital is influenced by the extent of a firm’s real earnings management via real transaction structuring activities (REM). Thus, the major purpose of this paper is investigating and analyzing the relationship between proxies of real earnings management and cost of equity capital. The sample data used for the research consisted of financial reporting by companies listed by Tehran Stock Exchange (TSE). We examined the data of 104 companies from 1383-1387. Using a pooled cross-sectional least squares regression of the implied cost of equity measure with our proxies for REM and other risk factors, this study documents evidence that a firm’s cost of equity increases with the intensity of REM via real transaction structuring activities. The results showed that there is a significant relationship between proxies of real earnings management and cost of equity capital. Therefore, all hypothesis of this study were confirmed.

The concern about the effects of long-term, auditor-client relationships on auditor independence and audit quality has led to enact a series of rules that limited the relationships.While the question of mandatory auditor rotation has received continued attention from regulators as means of strengthening independence and improving audit quality, but support for mandating auditor rotation has been mixed.Becouse of regulators’ concern about the impacts of auditor tenure, this study examines the association between auditor tenure and an important feature of accounting, namely conservatism. In this study, conservatism is operationalized by using of Basu’ model that based on quicker recognition in earnings of bad news about expected future cash flows. By using of multiple linear regression for Tehran Stock Exchange (TSE) listed firms during 1381-1385, we document a positive and significant relation between auditor tenure and conservatism. In addition, by partitioning the sample based on the length of auditor tenure into three groups, primary results confirmed and it is observed that conservatism increases with auditor tenure. Collectively, the results imply lower conservatism for short auditor tenure. Thus, mandating auditor rotation may have an adverse affect on the conservatism in reported earnings.

Share is a salient feature in open and close company laws. Accordingly, we tried to analyze specific legal regimes in Common Law and Arabic Law to have a complete comparison. Legislator has defined the preference share in the note 2 of the article 24 of the Amendment to the Commercial code after definition of share in the same article but no particular. Legal regime and special circumstances and clearly specified for preference share. Key words: Definition Share – legal and advantage depend on preference share when the company is being liquid and is being wound up – kind advantage preference share.

In many cases, the stock prices had great fluctuations, without any change in specific and reliable information existed in the stock market. These defects in the standard financial theory make a field of study based on psychological theories called behavioral finance. Herd behavior as a part of this domain has special importance. In herd behavior, decision makers rely on other investor's decisions and follow them without any logical thinking. As a result, such decisions cause unconditional subordination of the other investor's behaviors and a large group of investors rush to opt the same stocks to purchase or sell without publishing any information simultaneously. In this research, Herding behavior in Tehran Stock Exchange is investigated. The research methodology is based on decrease of deviation of rate of return in stress periods compared with other periods. The results show that there is no herding behavior in four selected portfolio that are examined. There are similar results for tension periods with return decreasing and tension periods by an increase in returns too. Thus, investors had reasonable decision making and rational behavior. On the other hand, return standard deviation increases at the periods of stress similar with CAPM anticipation.

This study investigates and compares the economic value added, residual income valuation and abnormal earnings growth models in determining the stock market value of companies. According to the model of residual income valuation, the value of the company follows book value of equity and earnings by clean surplus accounting method and the value of the company follows abnormal earnings over time, based on abnormal income growth model. However, economic value added is exceeding Net Operating Profit After Tax (NOPAT) accounted according to imposed capital costs over time by dirty surplus accounting method. Our study sample included 115 listed companies in Tehran Security Exchange (TSE) during 2003 to 2008. For testing of hypotheses, we used pooled data. Adjusted Determination Coefficient, Mean Square Error (MSE), F statistics, Akaike Info Criterion (AIC) and Schwarz-Beizen Info Criterion (SBIC) used in comparison of models. As the findings showed, none of the hypotheses verified significant difference between explanatory powers in all three models. The findings also indicated that there was a significant relationship between the company value and accounting variables but there wasnt a significant difference between explanatory powers in determining the company values. It was also revealed that explanatory power of residual income valuation model was relatively higher than economic value added model and explanatory power of economic value added model was relatively higher than abnormal earnings growth model.