محمد فقهی کاشانی

Companies adjust their voluntary information disclosure based on the volatilities they experience in their cash flows. Focusing on the digital industry segment of the Tehran Stock Exchange during the period 2012–2022, the current study aimed to investigate the effects of news related to risk, ambiguity, and ambiguity aversion on the policies adopted by firms regarding voluntary disclosure of soft and hard information. The analysis employed dynamic panel models to explain the voluntary disclosure behavior by the selected companies. The corporate voluntary disclosure lag was also used to capture disclosure dynamics, along with control variables including cost of capital, financial leverage, and stock liquidity. According to the results, managers of digital industry companies respond differently to news concerning risk, ambiguity, and ambiguity aversion depending on the type of information available for voluntary disclosure—whether disclosed conservatively or non-conservatively. This variation may be attributed to the nature of the disclosed information and its perceived credibility by investors. Furthermore, the findings confirmed that voluntary disclosures in previous periods positively influenced disclosures in subsequent periods, suggesting the presence of inertia in voluntary disclosure policies in the digital industry.

Since the 1990s, many economists have taken different approaches towards resolving the risk premium and risk free rate puzzles. Identifying causes of these two puzzles can help investors, regulators and policy makers in finding out determinants of the asset prices in financial markets and thereby shaping the real sector trends in the economy so that to improve their allocations efficiency. Meanwhile, the periodic incidence and prevalance of ambiguity environment in many economies, especially economies with more fragile institutional and economic structures, such as many developing economies, including the Iranian economy, have turned attentions towards highlighting the consequences of ambiguity for investors’ decision-making and policy design by policy makers.Within a parsimonious continuous-time stochastic general equilibrium model including heterogeneous agents with ambiguity aversion, this study shows how by a utility function with constant relative risk aversion coefficient augmented with variable investment opportunities and financial friction, one can still make a more justifiable account for the above dual puzzles. Model calibration indicates that the model fits better with the stylized facts detected for different time periods.

In this study, in order to investigate the impact of financial development and financial market fragility on the effectiveness of inflation targeting on the inflation rate, dynamic principal component analysis has been used to investigate the financial development index, and for The First Time, the price-to-earnings ratio (P/E) has been used as an index of financial market fragility. The findings indicate two prominent features regarding the impact of the inflation targeting monetary regime and the fragility of the financial market on the inflation level. First, the effect of the financial market fragility on the level of inflation has been "dependent on the monetary regime" governing the selected economies. Secondly, the inflation level implication of the inflation targeting monetary regime is "dependent on the state" of financial market fragility. The interaction of these two features, we see a kind of "threshold feature" regarding the influence of this monetary regime on the inflation level. More to the point, as to the financial market fragility, we see a kind of positive association between the level of inflation and the increase in the fragility of the financial market. Meanwhile, this positive association is more intense in the countries that adopt the inflation targeting monetary regime. However, concerning the cyclical risk of financial market fragility, the results generally show that if the financial market fragility is more than the market expected trend, it has a decreasing effect on inflation and the reverse holds true asymmetrically in terms of size.

In this article, the effects of productivity, foreign prices and oil exports shocks on the main variables including production and consumption were investigated, in a small open economy and in a situation where the country has adopted a policy of stabilizing the exchange rate. In this analytical space, under certain conditions, a cycle between the government and the financial and real sectors is created, which leads to the repeated reduction of the government primary surplus, and thus increases the probability of the government's inability to repay previously issued bonds and decreases the value of government bonds. This process ultimately leads to government debt-overhang, banking crisis and the reduction of total production and Consumption. For this purpose, the literature of "Fiscal Theory of the Price Level" (FTPL) has been used to analyze the performance of the government, which seems to be compatible with the institutional and legal conditions of Iran. According to this theory, the government, in some situations, can become the dominant actor in determining the general price level, and monetary policies are mainly regulated in accordance with the government fiscal policies. The above-mentioned process was implemented in a simple dynamic general equilibrium model that describes the behavior of actors in the economic environment, and the results on the variables of the model were analyzed. As a result, it was observed that the introduced shocks, such as nominal or real, even without any price stickiness and in conditions where domestic goods are priced based on global values, can have detrimental real impacts on key economic variables and public welfare.

Oil revenue management in the Iranian economy has been an important topic in recent studies. This study addresses the effects of shocks propagating from oil sector to other sectors by pplying proposed fiscal rules. Given the key role of governments and the financial system in propagating oil shocks in resource-rich economies, this study considers both sectors. A dynamic stochastic general equilibrium (DSGE) model in which government expenditures are dependent on oil revenues has been designed and simulated for Iran's economy. The proposed fiscal rules are the setting a floor for the oil fund (OF) oil inflow and imposing the fund balance floor. To examine the importance of the oil revenues coefficient, we treat it as a variable in the model and examine the impact of shocks on it. The results show that oil revenue coefficient is an effective tool for applying fiscal rules and has a large impact on macroeconomic variables. Applying a floor to the OF oil revenues coefficient is more effective at mitigating the effect of oil shock on macro variables fluctuations than setting a floor on the fund's balance. Both policies help to stabilize macroeconomic variables and preserve the share of oil revenues for future.

Market liquidity risk is a crucial factor in asset valuation, and understanding the influential factors on liquidity risk holds paramount importance. One of the key influential factors is exchange rate risk, a dimension often overlooked in the existing literature. The objective of this research is to investigate the impact of exchange rate risk on equity market liquidity risk. The study utilizes quarterly data from selected stocks of 32 companies listed on the stock exchange during the years 1386-1400. The liquidity risk is extracted using the Amihud measure (2002), and the risk is calculated through the detrended method. Various dynamic panel data models are employed for estimations, controlling for the effects of exchange rate risk alongside other explanatory variables, including market excess return, product prices, risk-free return, size, and book-to-market ratio. Results from the generalized method of moments (GMM) estimator indicate that an increase in exchange rate risk leads to an elevation in equity market liquidity risk. Additionally, market excess return and the book-to-market ratio exhibit positive effects, while product prices, risk-free return, and size show negative impacts on equity market liquidity risk. The degree of stickiness in liquidity risk is found to be minimal based on the dynamics of the model, and seasonal shocks have limited effects on equity market liquidity risk, suggesting a high level of stability.

One of the most important economic goals of countries is to provide financing from the securities market in order to prevent banking crises. Therefore, the impact of the base volume in the Iranian securities market to prevent speculation and in order to improve liquidity will not be possible except with the increasing link of economic ethics. The purpose of the current research is to investigate the consequences of reducing moral hazard on the application of the base volume and its relative costs on the liquidity of the securities of knowledge-based companies in the Tehran stock market.               

The method of the current research is practical and of the type of machine learning and the method of generalized moments. Two groups of small-medium stocks (a case study of knowledge-based companies) and large companies in the Tehran stock market were selected as the statistical population, which were selected from the ranks of the target population in 2014-2021 as the research sample. The data measurement tool was the Iran Stock Exchange website. The decision tree and torque method was also used for the test.

The fit of the research model, which included a main hypothesis, was confirmed. Therefore, the application of volume based on the market liquidity of two groups has a negative effect, which is more for knowledge-based companies and can cause moral hazards in pricing.

The Amihud index was used for estimation and the experimental results indicate that the volume of the base has a high importance in the lack of liquidity in the market, which is more important for knowledge-based companies and shows that it can cause moral hazards.

In the labor market literature, Shimer's criticism of the standard search and matching models indicates a low elasticity of the labor market as to the technology shock. As a result, the standard search and matching model is not able to explain the fluctuations observed in the main variables of the labor market, such as unemployment and job vacancies. In other words, in the standard model of search and matching with Nash bargaining, the fraction of fundamental surplus is large. Various explanations have been proposed to increase the elasticity of labor market compression to changes in productivity, and they all entail reducing the fundamental surplus fraction. By integrating the current and expected monetary policy induced debt overhang friction in the production and financial intermediatory sectors with a standard search and matching model this study aims at analyzing and pursuing how inclusion of this friction, through reducing the fundamental surplus and raising elasticity of labor market compression, could explain the excessive volatility in unemployment and job vacancy opportunities and thereby rendering a new solution for the Shimer’s puzzle. Further, the basic idea of this research was developed within a dynamic stochastic general equilibrium model including the key components of the search and matching model entailing the fundamental surplus fraction.  The resulting integrated model can be viewed as a theoretical framework for investigating the implications of including long-term risky nominal debt and the debt overhang for the fundamental surplus fraction in the structure involving financial frictions and the main features of the search and matching model subject to firm-specific productivity shocks and inflation. Considering the Iranian economy features, the model has been simutated for two cases one involves inertia in prices and the other one entails flexible prices.  The findings show that a monetary regime that leads to inflation would ensue the debt overhang episodes via reducing the real value of companies' debts. As leverage and default rates upsurge, firms pass up new investments and this leads to reduced labor force recruitment, job vacancy opportunities cut, and increased unemployment. As such, the debt overhang in companies lowers the fundamental surplus fraction and thus aggravates the impact of shocks on the elasticity of the labor market compression.

This paper investigates the effects of rule-based prudential policies on the banks competition in the deposit market. Using the imperfect competition structure and focusing on heterogeneous banks, we develop a partial equilibrium model, under which implications of how capital adequacy ratio regulation is implemented either discriminatory between banks (micro) or non-discriminatory and uniformly for all banks (macro) will be analyzed. Among the features that are emphasized in this analytical model is the role of self-regulation of bank capital in building confidence in the banking network in a non-linear manner. This, in a range of capital adequacy ratios, has featured the use of that prudential policy tool as a self-defeating one for the policymaker's goal in curbing the portion of high-risk projects in the targeted bank's assets portfolio. Further, a channel to explain the role of monetary policy in establishing stability or fragility of the banking network is introduced. In particular, the role of investors' degree of risk aversion in motivating banks to set their monitoring efforts has been evaluated.

This paper shows the inability of standard search and matching model to replicate labor market volatility in a selected developing country and especially in Iran's economy. To do this, we present empirical evidence on the cyclical behavior of the labor market variables in the selected developing countries. We then build, parameterize, and simulate the standard search and matching model and compare the simulated statistics to the data. The results indicate how those models fail in replicating the stylized facts concerning the unemployment and job vacancy volatilities following a standard productive shock. Likewise, the model is unable to generate as much volatility on the market tightness as in the data. Also, the search and matching model cannot explain the observed volatilities in unemployment and job vacancy in Iran's labor market in response to the labor productivity shock, and the calibrated model is able to explain less than 0.25 percent of the observed volatilities in the market tightness. This suggests a need to explore alternative sources of shocks and frictions in labor market of Iran. In general, one could contemplate augmenting the search and matching model with features such as wage flexibility, price stickiness, endogenous job separation under different types of shocks along with some developing countries-specific features.  All in all, this paper contributes essentially to the literature on empirical investigation of the business cycle properties of labor market variables within a search and matching prototype for selected developing economies. The inability of search and matching model to predict fluctuations in the labor market variables in Iran's economy and developing countries have not been quantitatively investigated so far, and this paper is the first quantitative work in this field.

Although theories over portfolio speculation have made remarkable progress so far, the performance of its proposed portfolios depends largely on the degree of accuracy in predicting future stocks prices dynamics. This study focuses on improving the performance of optimal portfolios by modeling the stocks prices dynamics through a time-inconsistent multivariate diffusion specification with drift vector. To this end, the share prices are simulated by means of a semi-martingale process with time inconsistent (local) martingale and information drift parts over the entire optimization horizon. Then, using the results of price simulation, we have looked into its consequences for constructing the portfolio of assets in the framework of Sharpe ratio maximization method and mean-variance analysis. Findings indicate that for the stock market under study (Tehran) within the trading dates spanning the interval 24-Mar-2001 to 19-Sep-2020, return and risk (standard deviation) of the portfolios obtained from applying this simulation scheme for mean-variance analysis and maximization of Sharpe ratio are both respectively higher and lower than those realized by the conventional methods. Additionally, a comparison of the simulation approach with performance of the actual market portfolios indicates that the Sharpe ratios of the simulation method is higher than those resulting from the market portfolios.

The purpose of this study is to investigate the unemployment volatility puzzle (Shimer puzzle) for the Iranian economy. For this purpose first, the behavior of the main variables of the labor market such as unemployment, vacancies, productivity, and the ratio of vacancies to unemployment (labor market tightness) using quarterly data from 2001-2018 investigated and then the ability of search and a matching model (DMP) to show fluctuations business cycles in the labor market were assessed through calibration on the Dynare. The results show that the search and matching model is successful in predicting the cyclical pattern of labor market variables, although it cannot explain the fluctuations observed in unemployment and vacancies in response to labor productivity shocks, and the calibrated model is able to explain less than 1/4 the observed fluctuations in the ratio of vacancies to unemployment. This study is the first quantitative work in this field for the Iranian economy that can be the basis for future research, including by recognizing the characteristics that are specific to the Iranian labor market can provide a solution appropriate to these characteristics for the Shimer puzzle. As long as the search and matching model is used to design and evaluate labor market policies, it is necessary to take into account the characteristics of business cycles of labor market variables, so it is suggested that more studies be conducted to identify the characteristics of Iranchr('39')s labor market that bring the search and matching model closer to the data.

The aim of this study is to theoretically investigate the role of the bank deposit market structure in how effective micro and macro prudential policies in determining the regulatory capital of banks in combination with monetary policy. To achieve this, a partial equilibrium analytical framework has been developed that includes rational economic entities and the possibility of contagion risk in the banking system in order to achieve more explicit and tangible results. In general, it will be shown that the imperfect structure of the bank deposit market as a policy transmission channel (which is less considered in the literature) can significantly change the micro and macro implications of such policies. Specifically, the effects of these policies on allocation and stabilization efficiency will be followed in terms of the types of conceivable equilibria for deposit rates, expected net returns, expected markup, and the level of expected effort of banks operating in the banking system. Expected markup capital elasticity of banking system smaller than one at the micro and macro levels play a special role in prudential policies. Each bank interactively with other banks would shape its solutions and expectations towards upcoming states of the economy (in so doing customizing its balance sheet asset side) along with key determinants for its solvency in respecting its financial obligations to depositors and whereby touching depositors’ confidence in its performance so hard that seizing utmost share in deposit market by bidding appropriate deposit rate. The deposit rate together with the level of monitoring efforts would further hit banking sector contagion risk drawing in its associated externalities and under well-defined conditions could expose the banking system to higher fragility.

This paper is an endeavor towards investigating the potential role of deposit market structure as a distinct channel for (monetary, fiscal, and regulatory) policy transmission mechanism. In doing so, we have developed the core idea in a rational expectation partial equilibrium setup incorporating the possibility of contagion risk in the banking system. This has enabled us to build up more sensible analytical findings within a tractable structure which is capable of making diverse equilibria spotted in some empirical evidence. The setup/paper lays down conditions under which one could expect Nash equilibria involving, inter alia, “limited price war”, “deposit rates rat race”, “bank run”, and “systemic banking crisis” followed by incidents of “banking panic”. This multiplicity in equilibria is the result of interaction between the deposit market structural characteristics and policy commands due to externalities originating from strategic complementarity/substitution among the rivalry banks in the market. Further the paper explores the allocation and stabilization efficiency implications in terms of conceivable equilibria for deposit rates, deposit market share, expected net returns, expected markup, and the level of expected effort of banks operating in the banking system with an emphasis on the role of equity capital in between.

This study aims at getting a better performance for optimal stock portfolios by modeling stocks prices dynamics through a continuous paths Levy process. To this end, the share prices are simulated using a multi-dimensional geometric Brownian motion model. Then, we use the results to form the optimal portfolio by maximizing the Sharpe ratio and comparing the findings with the outputs of the conventional model. To examine the robustness of the results, we have evaluated its performance for different investment horizons and various volumes of price information over a long period (approximately twenty years) in the Tehran Stock Exchange (TSE). Findings indicate that within the trading dates spanning the interval 24-Mar-2001 to 19-Sep-2020, the return of the portfolios obtained from applying this simulation scheme for maximization of Sharpe ratio is (244% on average) higher and their risk (standard deviation) are lower (1227% on average) than those realized by the conventional methods. Additionally, a comparison of the simulation approach with a performance of the actual market portfolios indicates that the Sharpe ratios of the simulation method are higher (0.055% on average) than those resulting from the total market performances. The results of the stochastic dominance test show that our proposed strategy has a first-order stochastic dominance (FSD) over the conventional one and market portfolios, that means at each level of cumulative distribution, the Sharpe ratio of our method is higher, and as FSD test makes no assumptions about the curvature of investors' utility functions, these results do not depend on the degree of risk aversion of investors, and as long as investors prefer a higher Sharpe ratio, they would be better off if they follow our proposed strategy.

This paper takes a novel perspective in analyzing theoretically how the sovereign wealth funds (SWFs) would impact on the sovereign risk, and thereby, the financial sector and, due to some frictions, the real sector of its owner economy. This happens as we suggest SWFs could help in mitigating the extant financial markets incompleteness. In a standard dynamic (continuous time) stochastic partial equilibrium model, it is shown how the SWFs would, under certain conditions, mitigate its owner sovereign risk, in which case it leads to the possibility of impacting on external financing costs of financial intermediaries and corporate sector. In particular, we explore how the sensitivity of default and/or financial distress and/or debt restructuring against (domestic and/or foreign) adverse shocks to the economy would be less, when there is a SWF in the economy in comparison with when the economy lacks it. This is investigated for two sources of financing the SWF. Further, we argue how the costs and benefits of establishing the SWF would be affected by the (relative) size of SWF, its type, and the state of the financial (surplus) capacity in time of setting up the SWF. The externality associated with the establishment of the SWF for the sovereign risk and formation of the new channel for the transmission of monetary and fiscal policies have been examined too. Mutual interactions between the SWF and the monetary and fiscal policy within the analytical framework have been analyzed as well.

Iran's Islamic financial system, as one of the main sectors influenced by the overflow of systemic shocks of Iran's economy based on current institutional arrangements, has been considered in this study in the form of a random dynamic general equilibrium model. By setting the real exchange rate as a sufficient statistic, this research examines the method of increasing the resilience of the economy based on Sections 8 and 9 of the General Policy of the Resistance Economy.
During the implementation of the model, the weaknesses of the applied methods in this area are investigated from linear and stationary non-accidental states aspects. According to the results, the global method with static random status has the maximum capacity to optimize the maximum resistance point.