Advances in Mathematical Finance and Application (AMFA)

In this study, I try to examine the effect of environmental sustainability on CEO risk taking. Prior research, however, has struggled to establish this relation empirically; moreover, some evidence points to the possibility that the CEO risk appetite is lower for firms with sustainable environment. The opportunistic approach of managers leads to decisions about personal interests and imposing costs on shareholders by decreasing risk taking. In order to investigate the issue, data on companies listed in Tehran Stock Exchange for the period 2008-2018 were extracted and a panel regression model was used to test the research hypotheses. Consistent with expected relation between CEO risk taking and the environmental sustainability, It decreases with respect to CEO opportunistic approach. Managers may benefit from increased fluctuations in risk orientation, but are more sensitive than shareholders and have less restrictive choice that avoids higher risk.

In the first nine months of 2018, the triple increase of dollar price made the stock market an attractive place for speculation, especially for non-professional investors. Hence, this study was aimed to investigate the profitability of speculation in the foreign exchange market (dollar) and to compare it with investment in three indices of sugar, oil products, and basic metals. First, the conditional Sharpe ratio was calculated separately for these four assets. Then, six investment portfolios were developed for these four assets. The results showed although dollar speculation with mean daily return of 0.6% had the highest return among the ten investment assets, dollar speculation was ranked last, or tenth (0.096) in terms of performance and profitability by considering the standard deviation or daily conditional risk using conditional Sharpe ratio. Moreover, the results indicated that from among the six portfolios with equal weight, three investment portfolios consisting of merely Tehran Stock Exchange indices had a better performance than three investment portfolios comprising dollar speculation and each stock exchange index. It was also found that the risk of lack of capital diversification by investors was higher than that of accepting a higher-level risk.

Technical analysis is one of the financial market analysis tools. Technical analysis is a method of anticipating prices and markets through studying historical market data. Based on the factors studied in this type of analysis, indicators are designed and presented to facilitate decision-making on buy and sell stress and then buy and sell action in financial markets. This research evaluates performances and returns of 10 conventional technical analysis indicators based on the strategies set on the total stock exchange index, the total index of OTC market and 8 other (non-correlated) industry indices by using Meta Trader software from 2008 to 2018. Also, the significance of the difference between the returns of the indicators is tested using the buy and hold strategy. The results show a significant difference between the returns using some of the technical analysis indicators in some indices and buy and hold strategy. The effectiveness of technical analysis strategies varies across industries and EMA and SMA with respectively 6 and 5 repetitions, are the best strategies and BB with just one repetition has the least repetition. The investment industry index with the most repetition is the industry in which the strategies used in this study have been able to provide an acceptable return.

According to a method of earnings management activities that administrators can manage reported earnings from the definition of real activity. In particular they can be located across time and activities in a way that accounting period to achieve a certain revenue target. Conservative attitudes of auditors in presenting their views about the independence of the auditor can considered as a remarkable point in the audit function. The Purpose of this study was to investigate the effect of audit quality on earnings management real time IPO companies. For this purpose, the data of 128 companies listed on the Tehran Stock Exchange during the years 2007 to 2017 were evaluated. The results indicated that the audit quality increases in the year of initial public offerings. The results also demonstrated that there is a significant and positive relationship between the audit fees in the year of initial public offerings and the audit fees in the year after the initial public offerings. Also findings of the research show that earnings management through accrual items has a positive and significant relationship with initial stock offerings.

The present study aims to investigate the association between political connections and related-party transactions for the firms listed on the Tehran Stock Exchange (TSE). Sample includes the 485 firm-year observations from companies listed on the Tehran Stock Exchange during the years 2013 to 2017 and research hypothesis was tested using multivariate regression model based on panel data.We find that political connections are negatively associated with related-party transactions. In other words, politically connected firms are less inclined to exercise opportunistic behaviours by related-party transactions in comparison to other firms. Moreover, additional analysis reveals that the negative relationship between political connections and related-party transactions is more pronounced in larger firms.Our findings not only extend the extant theoretical literature concerning the stock political economy in developing countries including emerging capital market of Iran, but also help investors, managers, capital market regulators, policy makers and accounting standard setters to make informed decisions.

Abstract. In this paper we define and verify a subclass of harmonic univalent functions involving the argument of complex-value functions of the form f = h + ¯g and investigate some properties of this subclass e.g. necessary and sufficient coefficient bounds, extreme points, distortion bounds and Hadamard product.Abstract. In this paper we define and verify a subclass of harmonic univalent functions involving the argument of complex-value functions of the form f = h + ¯g and investigate some properties of this subclass e.g. necessary and sufficient coefficient bounds, extreme points, distortion bounds and Hadamard product.Abstract. In this paper we define and verify a subclass of harmonic univalent functions involving the argument of complex-value functions of the form f = h + ¯g and investigate some properties of this subclass e.g. necessary and sufficient coefficient bounds, extreme points, distortion bounds and Hadamard product.

The intensity of competition in business markets is to the extent that even the slightest strategic mistakes will lead to the failure of the organizations. The lack of knowledge and implementation of appropriate competitive strategies in such markets and, on the other hand, the failure to review the effects of these strategies on the types of cash flows in diverse capital structures is no also an exception to this rule. The subject of this study is to design and explain the affectivity model of types of cash flows in a diversified capital structure based on the type of strategy. The present study is an applied one in terms of objective, a quantitative one in terms of data type and a descriptive survey one regarding how to conduct. The statistical population consisted of all companies listed on the Tehran Stock Exchange during 2013 to 2017, among which 139 companies were selected as the sample by systematic elimination method. The statistical method used is the panel data method and fitting the regression models has been conducted using the same data. The results indicated that there is no significant difference between the effect of the differentiation strategy on the cash flow of accounting and cash flows to equity in companies that have a debt-based capital structure with companies whose capital structure is based on equity.

Network data envelopment analysis models assess efficiency of decision-making unit and its sections using historical data but fail to measure efficiency of its units and their internal stages in the future. In this paper we aim to measure efficiency of stages of bank branches and obtain efficiency trend of stages during the time, then to estimate their efficiency in the future therefore we can be aware of stages inefficiency before occurrence and prevent them. First, a two-stage structure including deposit collection and loan giving was designed for bank branches using literature review and comments of experts. Human forces and fixed assets were considered as input variables of the first stage, deposit as mediator variable, delayed claims as interim variable, and loan amount as output variable of the second stage. Then, a dynamic network data envelopment analysis model was formulated and stages efficiency were obtained for 16 consecutive periods. Therefore, efficiency trend of stages was obtained during the time. In the following, efficiency of various stages of branches were estimated using artificial neural network and some recommendations are provided according to obtained amounts in order to prevent inefficiency before occurrence.

The purpose of this study is to compare the impacts of momentum on stock returns of companies listed in Tehran Stock Exchange in different market conditions. For this purpose, the sample size is 120 months from 2008 to 2017. The research hypotheses are estimated using multivariate linear regression using time series method. Based on the results of the hypotheses test, the momentum in each of the market conditions, including normal, ascending and descending conditions, has a positive and direct effect on the stock returns of the companies listed in Tehran Stock Exchange, which indicates the principle of investors' insatiability in the stock exchange Tehran seeking to maximize its return on investment with a certain risk that in a downside mode of market, their insatiability exits less and faster than their momentum conditions, which is a reason for investors' loss evasion in this situation.

This paper examines monetary and fiscal policy through the estimation of a New-Keynesian dynamic general equilibrium model for Iran’s economy. In this New-Keynesian dynamic general equilibrium model, the consumers encounter the liquidity constraint and the firms face sticky prices, while they are changing them. In the model presented, a role is considered for both government spending and taxation, besides the monetary rule. Then, the model is estimated using Iran's data over the period of 2002-2017, through the method of generalized moments which leads into valuable insight. The results indicate that aggregate demand reacts to changes in interest rates. When inflation occurs, regardless of its source, it is persistent and inertia.The monetary policy has a forward-looking behavior. The output gap with a lag has a negative effect on government spending and the short-term impact of the output gap on government spending is smaller than its impact on taxation (Tax responses to the output gap are stronger and positive).