نشریه پیشرفت های مالی و سرمایه گذاری
پیاپی 6 (بهار 1401)

As the business process becomes more complex, the risk of financial statements being distorted increases with each passing day. In this regard, researchers have been looking for models to detect fraud in financial statements. The purpose of this research is to present an expanded model based on the quality characteristics of the auditor.

Benish (1997) used a combination of financial ratios and accruals to predict profit manipulation methods. Since auditors are presented as external oversight in the corporate governance structure of the company's performance, in this study the model is developed based on the qualitative char-acteristics of the auditor, which include the auditor's size, auditor tenure, reporting delay, Auditor Class and Auditor Change. The fitting of the vector machine, random forest and neural network has been used to fit the ex-tended model.

The results show that the coefficients obtained from the random forest model are 98.4% and more than the two neural network and vector model 93%. Also, the extended model is more accurate than the base model. Audit characteristics are influential in predicting fraud in financial statements and should be considered by capital market participants.

Originality / Value:

Research findings can be effective in improving the prediction of fraud in financial statements and also draw users' attention to the combination of financial statement information and the characteristics of the auditor's report in fraud prediction.

The purpose of this study is to investigate the role of economic policy uncertainty in the relationship between voluntary disclosure of information and information asymmetry in companies listed on the Tehran Stock Exchange.

This research is descriptive, correlational and post-event. In order to investigate this issue, research hypotheses based on a statistical sample consisting of 138 firms during the years 2009 to 2018 and were tested using multivariate regression models.

The results show that the relationship between voluntary disclosure of information and information asymmetry is statistically negative and significant. The results also showed that economic policy uncertainty as a moderating variable weakens the relationship between voluntary disclosure of information and information asymmetry. This means that in a situation of economic policy uncertainty, with the reduction of inefficient fiscal and monetary policies and also the reduction of public distrust in economic decisions, voluntary disclosure of information decreases and as a result, information asymmetry increases. Economic uncertainty with disruption of the price system leads liquidity to unproductive activities and reduces the inflow of liquidity to production and thus reduces corporate investment.

Originality / Value:

The results of this study, in addition to developing the literature on economic policy uncertainty and information asymmetry, help capital market participants, decision makers, analysts and potential and actual investors of the Tehran Stock Exchange to analyze investment plans in financial assets and Securities should pay special attention to this important issue. The results also made financial and economic policy makers seek to create stability and create a safe investment environment, which is one of the basic conditions for the country's economic development, and by formulating long-term economic plans and taking into account the country's political and economic conditions, the necessary ground. Provide information to reduce asymmetry.

The purpose of this study is to predict stock returns and ultimately present a trading strategy based on dynamic analysis.

The behavior of a stock portfolio can be considered as a complex and chaotic dynamic system in which the return of the portfolio is a state variable that reflects the state of the system. Dynamic mode decomposition is one of the methods in which with the help of available data, a linear approximation of the nonlinear operator governing the system is obtained and by calculating the main modes, the system output can be explicitly calculated in terms of time.

The results of research on a portfolio consisting of 14 industries from the Tehran Stock Exchange in the period 1390 to 1399 and considering the 5 main modes of system guidance show that the optimal lag is six and the Sharp ratio obtained from the trading system of two Equivalent to the buy and hold system.

Originality / Value:

Therefore, the use of this trading system is recommended for short-term trading.

Since the Sudden changes in stock prices are unusual and usually negative which occurs in the absence of important economic events Therefore, it has always been considered. The purpose of this study is to investigate the effect of stock price crash risk on the future strength of the CEO. Accordingly, 103 companies during the period 2015 to 2019 have been surveyed. The results of reviewing the data collected during the period showed that the risk of crash in stock prices does not have a significant effect on the future strength of the CEO. As mentioned in the theoretical literature of stock prices’ crash, several factors can lead to this phenomenon, and management performance alone is not a sufficient condition to create conditions for crashing stock prices. For instance, according to the stock price bubble theory, stock price changes occur due to a shock without any proper and economic justification, and in fact cognitive errors that affect human psychology can affect investors' judgments in stock valuation and pricing. According to this, it seems that the crash in stock prices in the period under study was formed for reasons beyond the control of management and less managerial factors have been effective in crashing stock prices. Hence, the reduction of the CEO's power in this situation is unexpected. This finding provides new evidence in support of behavioral finance theory in stating that the CEO's future power is not affected by crashing stock prices.

The present study was formed with the aim of evaluating the optimal portfolio portfolio using market criteria using multi-criteria decision criteria under conditions of uncertainty in the Iranian capital market. This study was a combination of qualitative and quantitative research and its population in the qualitative section included 20 managers of Tehran Stock Exchange companies and university professors and in the quantitative statistical sample section, 30 managers and experts of listed companies. Which were purposefully selected and participated in the research. The results of the qualitative section based on the data method of the foundation showed that the effective criteria for evaluating the optimal capital portfolio include 5 market criteria. Market criteria include country risk; Systematic risk; Devaluation of the market; Devaluation of the equity market; Decreasing market profits. The results of the quantitative section were ranked using multi-criteria decision making methods. Based on this, first the general market components criteria were ranked based on AHP, which have the first to fifth rank criteria of country risk, reduction of company profit, reduction of growth opportunities, reduction of equity market and systematic risk in the market segment. Also, to electrify the sub-criteria (propositions), the method of electrification and topsis were used. Based on the Electra method in the foreign exchange market segment, sanctions and the risk of increasing the ratio of materials and products and sanctions were ranked first to third, respectively. Which showed the consistency of the ranking results in both methods.Originality / Value: Research findings can be effective in optimizing the portfolio portfolio and can also be effective in the current favorable market conditions in the Iranian capital market.

Predicting accounting earnings and its changes as an economic event has long been of interest to financial analysts and researchers.The purpose of this study is to investigate the effect of information environment on the relationship between consistency in book-tax differences and the accuracy of analysts’ of corporate earnings forecasts.

In this study, following the research of Choi, Hu and Khondkar (2020), the information environment and the quality of analysts' forecasts in two dimensions of predictive and prediction accuracy, consistency in book-tax differences in both temporary and Permanently dimensions were calculated and regression models were tested using the Generalized Torque Model (GMM). The selected sample consisted of 69 companies listed on the Tehran Stock Exchange between 2011 and 2020.

Generally findings indicate that consistency in book-tax differences has affected the prediction accuracy of analysts' forecasts. In a way, temporary consistency has led to an increase and permanent consistency has led to a decrease in analysts' forecast prediction accuracy. In addition, consistency in book-tax differences has also affected the analysts' forecasts predictive accuracy, which has been increasing for temporary consistency and decreasing for permanent predictive consistency.The information environment has also affected both the predictive and prediction accuracy of the analysts' forecasts.Originality / Value: The obtained results have led to the expansion of the theoretical foundations in relation to the factors affecting the quality of analysts' forecasts, in two aspects: accuracy and usefulness of forecasts. And besides that, it is useful for company managers in adopting the necessary policies to create a suitable information environment. The mentioned relationships are measured bilaterally and include temporary and permanent differences in the taxes paid by companies. which provides useful information in this field for standard setters and legislators.

 In order to manage operational risks as one of the most important risks of the banking system, it is important to create a comprehensive database of operational risk events. Therefore, the aim of the current research is to investigate the requirements and framework of creating such a database in order to prevent the occurrence of future harmful events and, as a result, manage operational risks.

 First, the operational risk framework and the general definition of each of the blocks of the framework including internal and external loss data, risk self-assessment and control, scenario analysis and key risk indicators were presented. Then, the internal loss data was further investigated, and the legal requirements regarding the necessity of creating a comprehensive database of risk events to calculate the capital required to cover the operational risk were raised.

 Database of operational risk events in order to meet the bank's risk management goals, it should have certain characteristics such as comprehensiveness, threshold, type of event at two levels, the amount of gross loss of the event, indirect costs, amount savings, profit, opportunity cost, Be close to losses, accounting adjustments, date, cause and description, business lines, currency type and border risk. Also in any organization, business sector He is responsible for the risks associated with his activities. After aggregation, the mentioned risks are reported to the bank's board of directors for decision making.

Originality / Value:

 Creating a comprehensive database of operational risk events in banks, while recognizing these events and adopting appropriate strategies to prevent these events from occurring in the future, leads to the accurate calculation of the amount required to cover operational risks and achieve capital adequacy goals. It is desired by the central bank.