panel data

Considering the decisive role of corporate governance mechanisms and its relationship between the transparency of financial information, political communications, transactions with related parties and the performance of companies in this research, in addition to examining them, the effect of some control variables on corporate governance was investigated. has taken. The purpose of this research is to determine the influencing variables on the governance mechanisms, such as the structure of the board of directors of the internal audit company (intra-organizational monitoring mechanisms of corporate governance), major shareholders and institutional investors (extra-organizational monitoring mechanisms of corporate governance), Political connections, transactions with related persons have been used in the framework of a statistical panel (companies admitted to the Tehran Stock Exchange during the years 2005-2021) and in the framework of a multivariable logarithmic econometric model. In this research, the effect of institutional ownership structure, company profit volatility, company sales, Tobin's criteria and profitability (performance indicators), stock liquidity (financial transparency), political connections, transactions with related persons, among other variables. The control of the companies admitted to the Tehran Stock Exchange has been reviewed. The findings of this research show that if the factors of company profit volatility, company sales, stock liquidity (financial transparency), political connections, transactions with related parties and company performance change, the impact of all variables except the profit volatility variables will change. Companies, political connections,stock exchange and the relationship between the performance structure of the companies and the liquidity of the shares and the institutional structure. (Political communication) is evaluated positively .

Knowledge management in auditing increases the efficiency and effectiveness of auditing; Because it can reduce the time required for the auditor to receive and check customer information and thus reduce the cost of the audit. With this reasoning, the main goal of researchers is to investigate the relationship between strengthening knowledge management and reducing audit costs. The time domain of the research is from the beginning of 1395 to the end of 1401. 130 companies were selected for this research. Then, the final analysis of the multiple regression model was done with the help of Stata version 16 software. In this research, 910 data (year-company) were examined and analyzed based on the fixed-data panel method. The results showed that knowledge management in auditing has a significant and inverse relationship with audit fees. In addition to these additional findings, the control variable company size has a direct and significant relationship with the dependent variable. In addition, it showed that the independent and control variables in the model were able to explain 57% of the changes in the dependent variable.

The purpose of this research is to investigate the effect of ownership characteristics on the auditor's modified opinion in companies admitted to the Tehran Stock Exchange. To achieve this goal, the companies admitted to the Tehran Stock Exchange were considered as the statistical population. Among the existing companies, 98 companies whose information was available during the period of 1390 to 1400 were selected as the final sample and analyzed. The method of data collection was documents and data collection tools were information companies of Tehran Stock Exchange.In order to analyze the data, Blodgit regression model and Eviews software were used. The obtained results are indicative according to the estimated model of the share ratio of all directors in the board of directors with an impact factor of 0.49, the share of non-executive (non-executive) directors in the board of directors with an impact factor of 2.1, the total share of internal directors in the board of directors with an impact factor of 2.6, Audit fees with an impact factor of 0.2 have a significant impact with a significance level of less than 5%.

The main purpose of this research is to investigate the effect of an effective audit committee on the company's performance during different stages of the company's life cycle. To check the performance, 4 criteria of added value of the market, Q-Tobin, return on capital, and return on assets have been used, and to show the index of effective audit committee, coverage analysis and three indicators of number, independence, and experience members have been used (statistics and the probability level of the Comeau and Bartlett tests confirm that coverage analysis can be used). According to the life cycle of the company, the selected statistical sample was divided into 5 categories: introduction, growth, decline, stagnation, and maturity, and 88 companies were used in the period from 2018 to 2022 to test the hypotheses. The results of the research show that an effective audit committee has a positive effect on the company's performance, and this effect is significant when the market value added performance index is used. But, the impact of the effective audit committee on performance was determined to be different according to the different stages of the life cycle, which is always positive.

Since tax constitutes a major part of the government's income and is the most common and most important method of providing government spending to ensure social welfare and economic growth, therefore regardless of taxes and important factors in avoiding paying taxes, economic growth and increasing public welfare in the long term It is not possible. Therefore, the main purpose of the research is to examine the relationship between the effective tax rate and the risk of companies listed in the Tehran Stock Exchange, emphasizing the components of tax culture. The data of this research includes the financial information of listed companies from the beginning of 2007 to the end of 2016. In this research, the panel data model was used to check the hypotheses. The results showed that there is a significant and direct relationship between the lower effective tax rate and sub-indices of tax culture (tax laws, crimes and forgiveness, awareness, social justice), with future tax rate fluctuations and future stock price fluctuations. Therefore, it is necessary to use the funds from tax avoidance activities in the field of investment to increase the expected future cash flow and as a result reduce the cost of capital.

Promoting tax culture is a significant challenge in the tax system. In Iran's tax system, based on self-reported tax liability, voluntary tax payment is low because the tax system is inefficient. Thus, it is very important for Iranian policymakers, decision-makers, and managers to gain knowledge about the prevailing tax culture in the society. A progressive tax culture can significantly contribute to Iran's economic development. Therefore, factors affecting the tax culture must be identified and effective measures should be taken into account accordingly. This study is applied, descriptive-correlational study examines the relationship between tax culture and risky tax-avoidance in companies listed on the Tehran Stock Exchange. The research data included the financial data of the listed companies form 2008 to 2017. Regression panel data is applied to test the research hypotheses. The results show that there is a significant and positive relationship between tax culture and lower effective tax rates with prospective tax rate fluctuations and stock price fluctuations. Hence, more attention must be paid to the tax culture in taxation. Additionally, the funds arising from tax avoidance should be utilized in investment to increase the projected cash flow, and as a result, reduce the capital costs.

In this article the joint effect of holding equity by banks (INV) and their capital adequacy (CAP) on bank lending is analyzed. The rules of banking industry and academic researches confirmed interaction between these factors, so this study centralized on designing a relation that can consider two factors as a single index, and then examine its effect on lending. To do this investigation it was considered 21 banks of private sector in 1390-1395. Results show that each item CAP and INVhas a negative & meaningful effect on lending but when they were considered as one factor the effect would’nt be meaningful. Liquidity, Npl and structure of source & use of bank has a negative & meaningful effect on lending. (Internal Items) Rate of gdp growth has a positive & meaningful effect and rate of loans wich is adjusted by inflation has a negative & meaningful effect on loans. (External Items)

In this paper, we evaluate the effect of petroleum and petrochemical industry and corporate governance on the relationship between employee differential and free cash flow with earnings management. We test the research hypotheses by applying regression and correlation techniques during 2012-2016 for companies listed in Tehran Stock Exchange. Findings show that the independence of the board has a decreasing effect on the direct relationship between employee differential and earnings management. Also, the institutional ownership has a decreasing effect on the relationship between employee differential and free cash flow with earnings management. On the other hand, Audit quality and company’s activity in petroleum and petrochemical industry are not significant on the relationship between employee differential and free cash flow with earnings management. It is necessary for investors to consider institutional ownership and independence of the board as two effective variables in decision making.

One of the mechanisms in which managers make optimal investment opportunities and achieve optimal corporate performance is the structure of corporate cash assets, which in the theoretical literature in developed countries is another mechanism of decision making by managers in using Optimal for investment opportunities and success. Good performance of companies. This research is a causal library and analytical study, based on the analysis of panel data (data panel). In this research, the financial information of 250 companies in Tehran Stock Exchange during the period from 2009 to 1395 was investigated. To analyze the results of the software, 10 Eviews have been used. According to the analysis of the hypotheses of the research, we concluded that there is a meaningful relationship between the economic value added and the amount of cash assets in the companies that have been granted to the Tehran Stock Exchange.

In this article, based on the level of levy in the country during 1379 to 1390 was attempted to divide the country into three regions, called them developed, less developed and underdeveloped each of these areas, include provinces, which are selected according to available data, there has thus developed region includes nine provinces, less developed and underdeveloped regions, each consisting of six provinces, and the other provinces have been removed. Also, using panel data to identify the factors affecting the tax capacity of the various provinces and it was found that the value added of industry and mines of GDP, the share of value added services sector in GDP, Per capita income and the investment are meaningful variables. At last by using maximum calculated taxation through curved Lafer general form and compare it with the actual capacity of each province's tax The amount of any State tax gap has been calculated that in order for a developed region is 41%, The less developed regions and underdeveloped region which is 47%, The results of this study suggest that the tax gap is present in all regions and provinces, and even increased. Therefore, it is proposed to compensate for the: A – tax Culture. B- General tax plan and instruction on-the-job. C- Correction of rules and tax circular and D- other essential preparation and important enterprises will do.

The most important determinants of the level of profit are financing constraints, investment opportunities, firm size, and pressure from the stockholders, government regulators, and the firm's governing body. In general, corporate governance, consists of legal norms, culture, and institutions that determine the management conduct and corporate performance. In this respect, what is of greater attention is the growing presence of institutional and legal entity investors in the circle of the owners of the publicly traded companies. The aim of this study was to investigate the effect of dividend policy and the ownership structure on the financing constraints in the stock exchange market. The population of this empirical study consists of all the companies listed on the Tehran Stack Exchange during the period from 1385 to 1393 of which, through systematic sampling and screening process, 135 companies were taken as the sample. The results show: a) The percentage of stock owned by the largest shareholder has a positive and significant effect on the financing constraints (KZ) variable. b) the effect of active and passive institutional ownership on the financing constraints variable are, respectively, positive and negative, however, active institutional ownership is statistically significant and passive institutional ownership is statistically insignificant. Finally, c) the effect of dividend relative to total assets on the financing constraints is negative and significant.

In this paper the relation between liquidity and firm value considering the quality of disclosure as an intermediate has been examines. For this purpose, a model system of simultaneous equations using Panel Data and Seemingly Unrelated Regression Approach are used. The data used in the estimation of time series and related companies in Tehran Stock Exchange for the years 1385 to 1391 have been. The data are paired with the transparency and disclosure (TD) scores provided by Standard and Poor's which are used. Also we employ three liquidity indicator the log of trading volume, the Amihud illiquidity ratio, and the proportion of zero-return days. Based on the results, liquidity thereby increasing the company's value will improve directly through its effect on Tobin's Q indicator and indirectly by improving the quality and level of disclosure has been made.

The objective of this research is to measure cost efficiency and profit efficiency of Iranian commercial banks and to investigate relationship between the measured efficiency and some variables composed of size, capital adequacy ratio, cost to income ratio and profitability. With respect to the above-mentioned objective, this research is accomplished in two steps. First, using DEA technique, cost and profit efficiency of 10 banks over the period of 2006-2010 is calculated. Then, utilizing panel data regression, the correlation between cost and profit efficiency and pre-determined variables is investigated. At the first stage, the sample banks are classified into two groups, i.e., efficient and inefficient, with respect to cost and profit. Moreover, among other findings of this research, is to equip inefficient banks with a path in which they can approach efficiency frontier. In fact, the DEA technique discovers reference units (among efficient banks) in order to determine optimum cost and profit required for inefficient banks. The results arrived from the second phase of this research indicate that some assumed determinants of efficiency including capital adequacy ratio and profitability ratio do not affect significantly the cost efficiency. However, the variables cost to income ratio and size have a significantly negative and positive effect on cost efficiency respectively at the 5% level, indicating that the banks more willing to control costs are more cost efficient and also the larger banks are more taking advantages of economies of scale. Moreover, among other results of this research is that except for the profitability variable, none of the other investigated variables, i.e. capital adequacy ratio, cost to income ratio and size, do not bear any effect on the profit efficiency significantly.