اندازه شرکت

This research aims to analyze the relationship between the cost of equity capital and social responsibility of companies by controlling the effects of company size variables, market risk and net return on assets. The research is of an applied purpose and descriptive-correlational in nature, and the Rahvard Navin software and the official website of the Tehran Stock Exchange Organization were used to collect data. Sampling by exclusion method was done among 203 companies for 4 years (1399 to 1402) and 983 observations were analyzed and for data analysis, Limer's F test, Hausman test and regression model were used. The results show that there is a negative and significant relationship between the cost of equity capital and social responsibility. Also, the results show that company size and return on net assets have a negative effect on the cost of capital, while market risk has a positive and significant effect on the cost of equity capital. These findings advise company managers that paying attention to social responsibility can help reduce financing costs, and investors are also suggested to prioritize companies with strong CSR performance in their investments.

The purpose of this research is to provide a model to determine the Stock Block Trading Premium in different industries of Iran's capital market. By using the background of past researches, the influencing factors on Stock Block Trading Premium were selected and analyzed in the proposed model. In this paper the companies admitted to the stock exchange of Iran were considered and the time period of the research were from 2010 to 2019. The relationships of the research variables were measured throughh Eviews and using multivariate regression analysis, and based on the output results of the models, research hypotheses were tested and the coefficients affecting the Stock Block Trading Premium were estimated. Finally, in order to investigate the difference in the effect of variables on Stock Block Trading Premium in different industries and to increase the accuracy of the findings, the variables have been investigated in Python. The results showed that the coefficient of each variable on Stock Block Trading Premium is different, and it has a direct relationship with the size of the block, cash, assets, and revenue, and has an inverse relationship with the debt ratio, profit, and company size. Further, the findings indicated that in the industries of petroleum products, coke and nuclear fuel and metal products; Profit; in the chemical industry; company size, in automobile and parts manufacturing ,banks and credit institutions; block size and in investment industry; Asset amount has the biggest impact on Stock Block Trading Premium.

The present study investigates the effect of transactions with related parties, financial crisis and company size on tax avoidance with emphasis on the mediating role of profit management. This research is practical in terms of its purpose, and from the point of view of correlation methodology, it is causal type (post-event). The statistical population of the research is the companies admitted to the Tehran Stock Exchange, and using the systematic elimination sampling method, 133 companies were selected as the research sample in the 10-year period between 1391 and 1400. The results of the research show that transactions with related parties have an adverse effect on tax avoidance. However, profit management has a direct impact on tax avoidance. Also, transactions with related parties have a direct impact on profit management. Company size has a direct impact on earnings management. Transactions with related parties have an effect on tax avoidance with the mediation role of profit management.

The capital market in a country is a major source of financing for companies and governments and is recognized as a good place for investors in all countries of the world. One of the things that is attractive to stock market investors is the awareness of the factors affecting stock liquidity. The purpose of this study was to investigate the effect of firm size on stock liquidity with respect to firm life cycle in listed companies in Tehran Stock Exchange. The statistical population of this study was composed of listed companies of securities exchange. The sampling method was systematic elimination and statistical sampling of 115 companies. The research period is 11 years from 2008 to 2018. The hypotheses were tested using multiple regression models and mixed trials. The results showed that as the size of the stock liquidity company increased, it increased. The size of the company also increases liquidity in three periods of growth, maturity and decline.

The main purpose of this study is to investigate the relationship between CEO power and capital structure decisions with an emphasis on the moderating role of firms size in listed companies in Tehran Stock Exchange.

In order to achieve the research purpose, the power of the CEO has been measured using the principal component analysis method and using the CEO task duality criteria, CEO tenure and CEO ownership percentage. Also, benchmarks such as book value leverage, market value leverage, short-term leverage and long-term leverage were used as capital structure representatives. Research hypotheses based on a statistical sample consisting of 106 companies during an 8-year period from 2011 to 2018 were tested using multivariate regression models and panel data

In general, the results show that there is no significant nonlinear relationship between CEO power and book value leverage and short-term leverage. Also, there is a significant nonlinear (U inverse) relationship between CEO power and market value leverage, and there is a significant linear (positive) relationship between CEO power and long-term leverage. In addition, in large corporations, there is a significant nonlinear (U shape) relationship between CEO power and book value leverage, market value leverage and short-term leverage, and there is a significant nonlinear (U inverse) relationship between CEO power and long-term leverage.

The results showed that the power of the CEO is one of the factors influencing the capital structure of companies. In other words, the effect of the CEO's power on the lever is complex, and it is simply incorrect to state a simple linear relationship. Also, the size of the company affects the relationship between the power of the CEO and the capital structure. Thus, in general, the results indicate that the powerful executives of large corporations do not take the same approach in their financing decisions.

Profit smoothing can be seen as a deliberate reduction in profit fluctuations, so that the activities of the company appear to be normal. Managers are making profit smoothing to reduce this volatility. Some experts believe that investors are more willing to invest in smoothing companies and are willing to pay more for them. Researchers believe that some of the characteristics of the company influence the motivation of managers to smooth profits. This study attempts to explain the theoretical foundations of the research, the relationship between earnings smoothing and company characteristics such as earnings quality, P/E and ROE and ROTA. Check the securities. In order to investigate the relationship between earnings smoothing and firm characteristics, data related to the period 2010-2017 were collected and analyzed. Logistic regression was used to test the research hypotheses. The results show that companies with higher price to earnings (P/E) ratios have more incentive to report earnings. And companies with higher earnings quality are more motivated to report earnings smoothly. Finally, it was found that larger ROTAs had a greater incentive to report earnings.

The purpose of this study is to investigate the effect of size of the company on the relationship between conventional returns, unconventional returns and heterogeneous investor beliefs.For calculate the size of a company from the natural logarithm of book value of assets, the unusual returns of the Fama and French Factor model, the conventional returns from the difference between fluctuations in stock returns and the volatility of unusual stock returns and nulligan beliefs by obtaining relative prices (model Below, 2008). 110 companies in the capital market of Iran during the period of 1385 to 1395 have been studied as a statistical society. To test the hypothesis , regression analysis has been used in combination data. The results of the study show that the conventional and unconventional returns of stock affect the heterogeneous investor’s beliefs and the effect of these two variables is greater on heterogeneous beliefs in large firms than in small firms. Thus, these components of stock return can affect investor confidence and challenge investment decisions.

The bubble in the stock market and in general in all markets is a real phenomenon that can cause losses to investors. The main problem facing each investor in the capital market is the decision to select the securities for investing and creating an optimal portfolio of stocks. Hence, stock valuation models have long been used by researchers  and investors. Solving  valuation puzzle reveals  the need to develop a comprehensive model that  describes the abnormal return . In this regards, although many efforts have been made and various models have been developed, none of these models has been able to fully explain this abnormal return. In this research, a pricing model in bubble conditions and an evaluation of the effective factors on stock returns are presented using the Fama-French model. For this purpose, the sample included 81 listed companies in the Tehran Stock Exchange( TSE) between 2009 and 2013, which have been selected . The results of this study reveal that among the five factors of the market, firm size, book value to price, momentum and bubble, only two factors of momentum and bubble affect the abnormal returns.

The aim of this paper is investigates the impact of surplus free cash flow, corporate governance and firm size on earnings predictability firms in the Tehran Stock Exchange. Free cash flow surplus and earn as independent variables. Also corporate governance mechanisms (independent board of directors, independent chairman, institutional ownership, and managerial ownership) and firm size as moderator variables. The final sample using of 100 firms listed in the Tehran Stock Exchange between2008 to 2014 research done. Linear regression analysis is used for testing the hypotheses. Free cash flow surplus and earn as independent variables. Also corporate governance mechanisms (independent board of directors, independent chairman, institutional ownership, and managerial ownership) and firm size as moderator variables. Result of the test hypotheses indicates that the excess free cash flow and Earnings predictability have effect.and there is also corporate governance mechanisms (independent board of directors, independent chairman, institutional ownership, and managerial ownership) on the relationship between excess free cash flow and Earnings predictability have no effect.

In this paper, the pattern of efficiency calculation with data envelopment analysis (DEA) is used to present a consolidated index for representing different dimensions of stock liquidity. Among DEA models, the range adjusted model (RAM) considers both inputs and outputs simultaneously; provide measure of efficiency and deals with negative inputs and outputs. Thus in this paper, RAM model is used as a basis for presenting relative consolidated index of liquidity. The next step, units with relative consolidated index equal to one is ranked, based on the full-inefficient frontier ranking method. Results support the effectiveness of data envelopment analysis application for measuring liquidity relative consolidated. Using this method, the stock liquidity consolidated index allocated to each of the companies listed on the, presents different aspects of stock liquidity for stocks in stock exchange, in a way that liquidity of stocks can be compared with each other easily and liquidity of a specific stock can be surveyed during time prides.

Earnings per Share (Eps) is an important factor in estimating the stock price of thr company……, in Gordon Model, the value of companys is a founction of dividend. Here we have investigated the comparison between the power of Profit and operating cash flow in earnings Per Share of the company. We took the Time series of 2010-2015anda number of 89 companies from amongst the listeed companies of the Tehran Stock Exchange. We also selected some effectine factors on dividevt, including the size of the company, debt ratio, current assets and last year dividend, as the control variables. The data structure is an integration of 527 expriments. Normal regression and extended regression showed that operating cash flow does not have the capacity of estimate the EPS and the results indicate that there is no significant relation ship between the sizeof the company, operating cash flow, current assete and dividend but there is a meaningful linear relationship between earmings Per share, debt ratio, last year and current year dividends.

Nowadays, information is the most part of the investment process. Information causes different decisions made by different people. Investor’s lack of knowledge about the effective factors on investor’s reaction could lead to overact or underact which ultimately would result to investor’s loss. This study examines the relationship between unexpectedProfit and the firm size on Profitresponse coefficient in the companies listed on the Tehran Stock Exchange about which the measurement of Profitresponse coefficient raised from cummulative abnormal returns, the amount of companie’s sales, unexpected profit raised from real and estimated profit and calculating the expected return, Fama and French Models were taken into consideration. For this purpose, about 135 typical companies in various industries listed in Tehran Stock Exchange for the period of 9 years (between 1385-1393) were analyzed (total 1215 firm-year) to study the relationship among variables to test the hypothesis of the study. The results showed that unexpected profit had significant positive correlation on the profit response coefficient on the companies under study and it had negative and meaningful correlation on the Profitresponse of the examined companies.

In this paper, by using different cash flow benchmarks (dividends, net income and free cash flow) for the period of 1381 to 1390 for listed companies in Tehran Stock Exchange, we showed that investors are changing their attitudes from dividends cash flow measure to net income and free cash flow methods in recent years which can be interpreted as increase in the Iranian capital market maturity and efficiency. On the other hand, in line with the hypothesis of interference of speculators on small company’s stock prices, by dividing companies in two groups of small and large, we find that because of their ability to manipulate small company’s stock prices, theyuse net income as a suitable cash flow measure.

In two recent decades, the investigation of herding behavior takes into consideration of many researchers. But a little research has done about the factors influence this phenomenon. The purpose of this paper is to investigate the role of momentum, investor's sentiments and firm size on the herding behavior in Tehran Stock Exchange. In this study, daily returns of market and firms for the period of 2001 to 2014 are used. In order to testing the research hypothesis multiple regression analysis and time series data are used. Furthermore, Granger causality tests for studying the Causal relationship between investor sentiments and herding behavior is used.
The research results indicate that investor's sentiments significantly effect on herding behavior. Granger causality tests support this result. But there are not any evidences about the influence of momentum and firm size on the herding behavior.

In this paper, the effect of the operating cash flow and capital structure decisions was examined on the investment decisions in the cases before and after the crisis separately for small, medium, and large firms. Sample of study included over 80 firms in the 12 years tested by using Estimated Generalized Least Squares (EGLS) estimation method and Generalized Moments (GMM) estimation method. The results indicate that there is significant and positive correlation between operating cash flows and investment decisions of Tehran Stock Exchange firms, while these firms have spent much operating cash in investment in periods after the crisis. In addition, there was significant and positive correlation between leverage and investment decisions of Tehran Stock Exchange firms in the period before and after the crisis, while this correlation declined in periods after the crisis. Results suggest that domestic cash flows have been used as sources of financing with significant application in three small, medium, and large firms. In this regard, medium and small firms significantly had the highest use of this resource for investment. Medium and large firms also significantly used debt for financing their investments.

The main purpose of this study is to investigate the relationship between various measures of the company's growth and the ratio of changes of retained earnings. This study is a library-analytic one and is based on panel data analysis. In this study financial information of all 101 companies listed in Tehran Stock Exchange during the period 2008 to 2013 were reviewed. To analyze the data, Spss20, Eviews7 and Minitab16softwares have been used. The findings of the study showed a significant positive relationship between corporate profitability and relative changes in retained earnings, and also a relationship between the size of the company and the ratio of changes in retained earnings of the companies. There is, however, a significant negative relationship between the company's growth opportunity and the ratio of retained earnings change.

This study is investigating the relationship between some companies’ characteristics, including assets returns, equity returns, company’s size, company’s leverage, market to book value of the company, Q Tobin and stock price crashes for the period of 2007 to 2013 (for the 7 years period). Hutton et. al (2009) model is used for measuring stock price crash. Results show that there is a negative and significant relationship between ROA, SIZE, MTB and Q Tobin but two other variables ROE and financial leverage have no significant relationship with stock price crash for the companies listed in Tehran Stock Exchange.

In the past two decades many researchers have used some kinds of factor models for explanation of stock returns. The aim of this study is comparing the explanatory power of two main multi-factor models in relation to stock returns. This study is based on a Carhart four-factor model. The variables in this model are market risk premium، value، size and momentum factors. The aim of this study is evaluating the explanatory power of this model in Tehran Stock Exchange. The multivariate regression is used to analyze the propositions. The results show that the use of multi-factor models is better than one-factor model of capital asset pricing. The results also show that the four-factor model has not the advantage of Fama and French three-factor model، because only two variables (market risk and size) influence on stock returns.