hadi sheikhi

The purpose of this research is to examine the dynamics of conditional correlation between the returns of mutual investment funds (4 selected funds) and the return of the total index of the Tehran Stock Exchange during the period from the beginning of September 2013 to the end of Faroudin 1400.

In order to achieve this goal, dynamic conditional correlation (DCC) and asymmetric dynamic conditional correlation (ADCC) econometric techniques, which are multivariate conditional heterogeneous variance (MGARCH) models, have been used.

The results of the estimation of EGARCH models for conditional variances indicate that there is asymmetry in the conditional variance equation for all the return series (other than the output of the Export Development Fund), so that bad news more than well news cause to further increased the turbulence of returns. The results of the DCC and ADCC models showed that the asymmetric parameter is only significant between the total returns of the market and the return on the brokerage business, and in other models, in the conventional level of knowledge, there is evidence of asymmetry in conditional correlations Does not exist.

The results of the current research indicate that bad news has a greater impact than good news on the status of funds; In fact, funds are conservative in the face of good news and relatively passive in the face of bad news.

Contribution: 

The lack of sufficient strength in facing the market with bad news can be considered as the major problem of investment funds.

The purpose of this study is to investigate the relationship between Earnings persistence, institutional investors monitoring, and types of political connections in companies listed on the Tehran Stock Exchange. The statistical population of this study is all companies listed on the Tehran Stock Exchange from 2015 to 2021 and the number of samples is 105 companies. The regression analysis method and Ivory statistical software were used to analyze the research data. The results showed that institutional oversight in companies with political connections has an effective role in increasing profit stability. The selection of large auditors by companies with political connections has no significant relationship with profit stability. However, the longer the term of the CEO of companies with political connections increases, the more stable the profit. The results generally indicate a significant relationship between profit stability, institutional oversight, and various types of political communication.

Auditors are always looking to identify factors that can be used for estimating the risk of material misstatement more accurately at the level of financial statements. In this regard, this study examined whether decisions to hire or fire the staffs that make an important part of the company's operations help to anticipate accounting misstatements and, consequently, whether this affect the timing of auditor's reporting of auditor's fee and resubmission of financial statements.The research period of 1392-1398 was considered, during which 105 companies listed on Tehran Stock Exchange (TSE) were selected as the samples and the research hypotheses were tested by using Ordinary Least-Squares (OLS) regression and binary regression. The results of testing the research hypotheses indicated that the effect of abnormal investment in the staffs on the delay in submitting the auditor's report and restatement of financial statements was not accepted, but its effect on auditor's fee was accepted. Our results showed that the auditors of the sample companies were able to correctly estimate the risk of material misstatement caused by abnormal investment in labor and other factors and plan their proceedings to cover the risk of material misstatement through proper and timely planning. The results of this study provided evidence that auditors pay attention to red flags in financial reporting when reviewing financial statements.

Identifying the factors affecting the cost of capital of the company is always one of the important issues for investors and managers. Therefore, in this study, the effect of quality of disclosure of financial information on the cost of capital of the company and also the effect of the CEO’s dual role on this relationship is examined. To calculate the company's capital cost, the Gordon model and the capital asset pricing model are used, and to measure the quality of disclosure, the quality of Kaznik's (1999) accruals and the disclosure index published by the Stock Exchange Organization are used. Also, the duality of the role of the CEO means that the CEO is simultaneously the chairman or vice-chairman of the board. Finally, the results of the test of research hypotheses on 148 companies listed on the Tehran Stock Exchange in the period 2012 to 2018 by regression method, showed that there are an inverse and significant relationship between the quality of disclosure and the cost of capital of companies. There was also no evidence of the duality of the role of the CEO on the cost of capital and the moderating effect of this variable on the relationship between disclosure quality and capital cost.

In this research the effect of accruals quality on stock risk premium of listed companies in Tehran Stock Exchange has been studied. for this purpose، and based on the three factors model of Fama and French (1993)، the difference of average return made by the strategy of choosing the companies with high accruals quality and low accruals quality between the years 1997-2008، has been used. the accruals quality of each company is calculated on the basis of Fransis et al model (2005). the survey results indicate that accruals quality do not have the ability to interpret the stock risk premium of the companies. Then، by forming 25، 50 and 64 mimicking portfolios separately، and running the two-stage cross sectional test on Fama and French model (1993) the effect of accrual quality on risk premium of companies has been examined again. The results of this test for all mimicking portfolios confirmed the inefficiency of accrual quality in determining the behavior of companies’ risk premium.

Environmental uncertainties always inflict their effects both upon companies and، upon their operations and reports. Thus، we examine the relation between environmental uncertainties and earning''s components (unmanaged earnings and discretionary accruals). For investigating this relationship، we use data of 101 listed companies on Tehran Stock Exchange for the period of 2005-2009، and set out to analyze the research hypotheses، using statistical methods of correlation and multi-variable regression. Findings indicate that environmental uncertainties do affect unmanaged earnings and، to modify their effects، managers do not try to manage the company''s earnings.