عباس معمارنژاد

Monetary policy is a tool through which central banks manage the supply of money to achieve their goals, and it is one of the key elements of macroeconomic management, and its effectiveness is an important issue in the analysis of economic policies. The usual goals of monetary policy are to achieve or maintain full employment, to achieve or maintain a high rate of economic growth, and to stabilize prices. For this purpose, in this research, the effects of this policy on production and employment, which have been calibrated for the Iranian economy by considering frictional unemployment in the form of a monetary general equilibrium model, have been investigated. The results show that the effect of monetary growth on employment and production in a steady state may be non-linear depending on the two parameters of labor supply elasticity and elasticity of vacancies in job matches, so that the lower the labor supply elasticity and elasticity of vacancies in job matches, it is more likely that monetary growth will have adverse effects on employment and production. Also, in the framework of the model, the negative relationship between the unemployment rate and vacancies is calculated, and with the increase of the Quarterly monetary growth rate from zero to 5%, the employment and production values in a steady state, they increase by about 0.4%. In addition, considering the transition dynamic, with the reduction of the monetary growth rate from the level of the benchmark case to the level of 2.5%, the equilibrium values of the variables will converge to their new equilibrium values after 2.5 years. Therefore, it is suggested that the central bank should pay attention to the effectiveness of monetary policy on production and employment in order to achieve macroeconomic goals in recession and boom. And since monetary growth is not always unfavorable for production and employment, the effects of this reduction on production should be taken into account in inflation reduction policies.

In this study, the effect of the components of the corporate governance system on the financial soundness of 12 banks in Iran during the period 2006-2023 was investigated using unbalanced panel data and fixed effects. In the present study, the CAMELS composite index has been used as a representative of the banking soundness index. The survey results have shown that among the corporate governance system's components, only the independent directors variable has a positive effect on the financial soundness. In contrast, the size of the board of directors, the number of meetings of the board of directors, the number of meetings of the audit committee, the duality of the CEO, and the number of meetings of the risk monitoring committee have a negative impact on the financial soundness of banks. In general, it can be expressed that the corporate governance system does not have a desirable effect on the financial soundness of the studied banks in Iran, which can be caused by the lack of real establishment of the corporate governance system in the country's banking system, especially in private and privatized banks, the absence of a correct strategy, corporate governance, lack of monitoring mechanisms, lack of proper transparency and effective accountability regarding information disclosure, poor management of assets and liabilities, etc.

In this study, the effects of industrialization, economic development, financial and commercial market liberalization on environmental degradation are explained. For this purpose, in the form of the final model of the quantile panel for the period of 2000-2021, the current issue was investigated in (BRICS) countries and (OPEC) countries. The results and estimation of the quantile model show that in the first and second (bottom) quartiles; Energy consumption per capita, stock market development index, financial development, trade, gross domestic product per capita, added value of the industry sector, labor and capital have a positive effect on the potential of global warming and carbon dioxide emissions in (BRICS) and (OPEC) countries. and from the third and fourth quarters onwards, the intensity of its impact decreases in (BRICS) countries and increases in (OPEC) countries, in other words, the study indicators in the first (Q25) and second (Q50) quarters, with global warming and the emission of di Carbon dioxide has a positive time correlation in both groups of countries. Then, as the lag components move away and move towards the third (Q75) and fourth (Q95) quartiles, the correlation between the study indicators and global warming and carbon dioxide emissions increases in (OPEC) countries and decreases in (BRICS) countries. This trend expresses the warning that in OPEC countries, much effort is not made to preserve the environment by reaching a high level of production, and it is necessary for OPEC countries, like advanced countries, to spend part of their income to preserve the environment as much as possible and Or use methods that cause less pollution and destruction to the environment in the path of their economic growth.

One of the aspects of improving people's health is to pay attention to environmental mechanisms that affect people's health with their ecological effects. In the current study, the effects of industrialization and economic development on the production of greenhouse gases are discussed in line with people's health.

in the present article, following the studies; Zhao et al. (2023), Yeboa et al. (2023), Zhou et al. (2023) and Wen et al. (2022) explain the effects of industrialization, economic development, on the production of greenhouse gases in line with the sustainability of people's health in countries (G7) and OPEC countries based on the quantile panel regression model and for the time period of 2000-2022.

The estimation results confirm the relationship between financial development and environmental degradation in two groups of countries (G7) and countries (OPEC). The estimation results also show the confirmation of the effect of energy consumption on global warming potential in (G7) countries and (OPEC) countries and energy consumption has a positive effect on environmental pollution, in (OPEC) countries due to the abundance of energy and natural resources, energy prices is low, which has caused excessive and incorrect use of energy.

It can be said that the development of commercial and financial markets can lead to the improvement of human capital in countries. But this will happen better when the right context is provided for the optimal allocation of resources and the efficiency of labor and capital is increased. Financial development is an important factor in economic growth and the health status of people, which affects the health status of people not only directly but also indirectly through the environment; Also, in addition to adding physical capital in various sectors of the economy, investment in human capital should also be made. The financial sector development mechanism works in such a way that financial resources are provided from various private and government channels for the health sector of individuals; Because the efficiency of health services depends on the correct management of health system resources and its connection with the governing financial system. Investing in human resources is the education and training of human resources to acquire different skills and advance production, which can increase production and achieve economic development by raising the level of skill and expertise of the workforce and increasing its productivity. (G7) is more intuitive.

This research estimates the simultaneous effects of sanctions, unemployment, inflation, and other factors with potential negative impacts on the economy, focusing on the context of Iran. The analysis applies a vector autoregression (VApR) model to data spanning Iran's economy from 1358 to 1400 (1979–2021). The findings highlight the detrimental influence of United Nations economic sanctions on Iran's economic growth. Increased government spending, higher unemployment rates, and rising inflation exert negative pressures on long-term economic growth. In contrast, increased investment and higher foreign exchange rates (in rials) enhance long-term economic growth but contribute to economic instability. This study addresses a critical need in economic policymaking by simultaneously assessing these factors' impacts.

In recent decades, the issue of strengthening the financial inclusion of the public in accessing financial services has become one of the priorities of policy makers and senior managers. The reason for the importance of this issue is that the strengthening of financial inclusion provides access to financing services for all income groups (including the poor), and this can strengthen the economic growth of countries and increase economic prosperity in the medium and long term. Therefore, in this study, the effects of financial inclusion on economic growth and stability in 30 provinces of the country during the period of 2006-2021 have been investigated using the vector autoregression method with distribution breaks, fully modified ordinary least squares and vector error correction. The results of the estimation of economic growth and stability model show that financial inclusion has increased economic stability and economic growth in the long term. It can argue that financial inclusion from both supply and demand channels has increased economic stability, growth, and development of investments. This impact can come from providing favorable financial services, improving and upgrading the financial system.

The main issue investigated in the current research is the investigation of the impact of audit committees on the financial and economic risk of cryptocurrency demand in companies listed on the Tehran Stock Exchange. For this purpose and following Mohammad et al. (2022), at first, the relationship between financial and accounting expertise, independence and professional competence of audit committee members with (specific and systematic) risk of companies was investigated and then the moderating effect of ownership Family based on this relationship was analyzed. In this study, the financial information of the companies accepted in the Tehran Stock Exchange was used in the time interval of eleven years between 1390 and 1400, and the final sample consisted of 141 companies. The findings of the present research showed that there is a significant relationship between financial and accounting expertise, independence and professional competence of audit committee members and companies' risk. In addition, family ownership has a moderating effect on the relationship between financial and accounting expertise, independence and professional competence of audit committee members and company risk.

This study aims to analyze the optimal monetary policy response to economic shocks in Iran using a Dynamic Stochastic General Equilibrium (DSGE) model. The focus is on determining the effectiveness of monetary policies in stabilizing the economy and enhancing welfare in the face of various economic shocks. The research employs an analytical-descriptive and applied approach, utilizing the DSGE model calibrated with data from 2011 to 2022. Data was gathered from the Statistical Center of Iran and the Central Bank of Iran. The DSGE model's calibration involved using existing data and studies to assign parameter values, while standard global literature values were used where local data was unavailable. The model was coded and analyzed using Dynare software. Results indicate that optimal monetary policies significantly improve economic stability and welfare. The study found that economic shocks, such as oil price fluctuations and changes in tax revenues, have substantial impacts on key economic indicators. The DSGE model effectively captured these impacts, providing insights into the necessary adjustments in monetary policies to mitigate these shocks. Optimal monetary policies are crucial for stabilizing the economy and enhancing welfare, particularly in an economy heavily dependent on oil revenues like Iran. The findings underscore the importance of adjusting monetary policies to counteract economic shocks. The use of DSGE models proves valuable in predicting and analyzing the effects of these policies, aiding policymakers in making informed decisions.

In recent years, financial inclusion increasingly has been raised as an important socio-economic issue in the political agenda of many governments and international institutions. Increasing attention to this issue is due to a better understanding of its importance and place in economic development and its key role in poverty reduction and inclusive and sustainable development of societies. Therefore, in this study, the effects of financial inclusion on the poverty and income inequality in 30 provinces of the country during the period of 2006-2020 have been investigated using the Panel Autoregressive with Distributed Lags model. The results of the estimation of the income inequality and poverty model show that financial inclusion in the long and short term has caused a decrease and an increase in the Gini coefficient (income inequality index) and the poverty (poverty index), respectively. In such a way that in the long term, with the increase in the financial inclusion index, the Gini coefficient has decreased by 0.91 percent and poverty by 0.20 percent. It can be argued that the existence of a strong financial market with low risk encourages investments. In addition to improving production and employment, this process improves income distribution and reduces poverty.

Investment is one of the main component of aggregate demand in economy which plays a crucial role in the economic fluctuations and economic growth of each country So economist and policymakers focused on interpret of Investment behavior.  One of the most important factors in the decision to invest in both domestic and foreign investment is the existence of a secure environment. in other words, the most important factors is the proper investment environment and what has been interpreted as the ease of doing business. In such a way that improving the ranking of countries in business environment indicators is one of the prerequisites for attracting domestic and foreign capital and as a result investment. The main goal of this study is to investigate the effect of indicators of ease of doing business and domestic investment on foreign direct investment in selected countries. For this purpose, based on the division of the World Bank, four groups of countries are considered by their income level, including low-income countries, lower middle-income countries, upper middle-income countries and high-income countries, and the effect of domestic investment and indicators of ease of doing business have been evaluated using a Panel data model. The result shows that the level of development of countries and their income influences the magnitude and effect of domestic private investment and indicators ease of doing business on FDI. In a low-income, lower middle income and high-income countries, the effect of investment on foreign direct investment is positive, and in the upper middle countries, this has a negative effect. Meanwhile, the effect of each indicator of ease of doing business on foreign investment varies depending on the income level of countries.

One of the most important risks faced by financial institutions is credit risk, which is formed by the possibility of the receiver's default in repaying the loan or repaying the loan on time. One of the pivotal financial institutions in Iran's economy is the Export Guarantee Fund of Iran. Being the exclusive official export credit insurance entity in Iran, it operates under complete government ownership, shouldering all obligations associated with the fund's coverage. Over the past decade, the Export Guarantee Fund of Iran, the sole provider of export guarantees in the Iranian economy, has undertaken the risk amounting to approximately $15.8 billion through the issuance of diverse guarantees and insurance policies. The most significant volume of claims pertains to credit guarantees. Based on available statistics and official records within the Iranian entity, it can be observed that between the Iranian calendar years of 1387 and 1397, this fund issued guarantees totaling $6.7 billion, with the largest claim, exceeding $317 million, originating from the credit guarantees provided for the benefit of creditors. Recognizing the significance of this matter, the development of an optimal model for evaluating the credit guarantees provided by customers of the Export Guarantee Fund of Iran holds the potential to mitigate credit risk and subsequently decrease the fund's incurred losses. Even a one percent reduction in the fund's losses could result in substantial savings, amounting to at least 1,330 billion Rials. This figure is poised to grow even further as the fund increases the issuance of credit guarantees. Consequently, the primary objective of this research is to identify the most effective method for distinguishing between creditworthy and high-risk customers, ultimately diminishing the default rate of loans extended by the Export Guarantee Fund of Iran.

In this study, an artificial neural network model was employed to create a risk assessment framework for applicants seeking financial facilities and guarantees from this fund. This model exhibits exceptional predictive capabilities, especially in estimating the likelihood of default for the granted facilities. To achieve this objective, a dataset comprising 2,170 credit files granted by this fund was utilized. A total of 69 intra-organizational and extra-organizational variables were initially considered, and their respective information was gathered. Subsequently, six key variables were employed in the ultimate neural network model, encompassing the credit recipient's province, the guarantee beneficiary (creditor bank), personnel count, current ratio, real interest rate, and economic growth rate.

Based on the neural network model, the best models were extracted with three methods Bayesian, Levenberg, and Conjugate Gradient, and with one to 30 neurons in the hidden layer. The best model with all independent variables (i.e., 69 independent variables) was predicted with 96.2% accuracy, which is more than the Probit econometric model.

The findings of this research offer the capability to distinguish between customers with favorable and unfavorable credit profiles. Furthermore, the credit rating of customers can be used as a basis for adjusting the collateral requirements for each customer group, thereby aligning the collateral amount with the creditworthiness of the respective groups. This means that if the customer is one of the customers with good credit and a good credit rating, less collateral can be obtained from them, and if the customer has higher credit risk, more collateral can be used as a guarantee of the repayment obligation. In this case, while measuring the credit risk and separating customers, it is possible to manage the risk and the credit portfolio of the Export Guarantee Fund of Iran optimally.

The health of the banking system is extremely important for maintaining the stability of a society's economy, the monetary system, the interests of depositors, and public trust in the entire banking network. In addition, since a healthy and stable banking system can better resist shocks and play a stronger role in the stability of the financial system, it is necessary to identify effective variables and components and determine how they affect the recovery and restoration of the financial health of banks. Several factors affect the financial health of banks. Some of these factors are internal and under the control of the bank management, and based on their specific impact on the health of the bank, they can be considered positive or negative. With respect to this fact, in this study, the internal bank factors affecting the recovery and restoration of the financial health of some selected private banks in the Islamic Republic of Iran during the period of 2011-2021 were investigated using the panel data method and fixed effects. The results indicated that corporate governance, liquidity, age of the bank, and business model have a significant positive effect on the banking health index. On the other hand, bank size, financial leverage, interest-free assets, and financial risk have a significant negative effect on the banking health index.

The banking system Soundness is very important for maintaining economic, social and political stability and ensuring sustainable development at the national and international levels. Therefore, revealing the factors affecting the health of banks and considering these factors in the design of economic policies is important. Several factors affect the financial health of the banking system at the company level and the country level. which have a different effect depending on the type and nature. In this regard, studies show that the performance and banking system Soundness is largely dependent on the environmental conditions of the macroeconomic environment with contradictory influence. According to this issue, in this study, the uncertain effect of macroeconomic variables and bank-specific factors on the health of the banking system of the Islamic Republic of Iran during the period 2001-2021 was investigated using the panel data method and fixed effects And with the benefit of Eviews software.The results of the survey have shown that corporate governance, economic growth, bank size and quality of supervision have a negative and significant effect on the financial Soundness index of the banking system. In contrast, the uncertainty of macroeconomic variables and banking competition have a positive and significant effect on the financial Soundness index of the banking system.

The objective of this paper is to examine the welfare cost of inflation in the context of Iran's economy, incorporating labor market frictions (search theory) within a monetary general equilibrium model. The model also features a cash-in-advance constraint. To achieve this goal, through the utilization of calibration and sensitivity analysis in the steady state, the findings indicate that both employment and production are contingent on the elasticity of labor supply and the elasticity of vacancies in job matches. Depending on these two parameters, they may exhibit an increase in response to an escalation in the inflation rate. Additionally, the three-month optimal inflation rate in a stable state is determined to be 4.66%. The welfare gains, derived from reducing the three-month inflation rate from its current level of 5.3% to the optimal rate in a steady state, is calculated to be 0.0031% of total consumption. Therefore, based on the results, it is suggested that in inflation reduction policies, the effects of this reduction on welfare are taken into consideration, and special attention should be paid to the area of business investment by giving tax incentives, especially tax credits.

Foreign trade and its relationship with economic growth is one of the most controversial topics, especially in the selection of development strategies in developing countries, and there is still no agreement among economists on how trade policies and full employment can be related. Also, the trade liberalization program as a process of reforming foreign trade policies is the basis for international competitiveness and the participation of countries in economic activities. Of course, in the course of this program, activities that do not have a good competitive ability will lose the possibility to continue working. For this purpose, the welfare effects of foreign trade policy reform on full employment in the period 1380 to 1397 through the method of autoregressive model with interruption A distribution has been investigated. The results showed that trade liberalization has a significant effect on employment by applying the policies of eliminating or reducing tariffs and increasing imports in the short term.

Numerous studies have been conducted on the effects of financial development on the economies of countries. But so , The present study, considering the problem of inhomogeneity using the Granger Markov Switching causality approach, investigates the nonlinear causal relationship between the size and financial depth of the financial sector and economic growth in Iran during the period 1352-1399. Value-added variables of the financial sector as a percentage of GDP as a variable of the size of the financial sector and the ratio of loans granted by the banking system to government and non-government to GDP as an indicator of independent financial depth Findings of this study show that in regime one (during 1362-1399), there is a two-way causal relationship between economic growth and financial size. Whereas in the zero regime, there was a one-way causal relationship from economic growth to financial one. Also, the findings of the study in examining the relationship between economic growth and financial development index, show that in the zero regime (during the years 1387-1387) there is a one-way causal relationship from financial depth to economic growth. While in the first regime no causal relationship was found between the two variables

Currently, imposing carbon tariffs is criticized as one of the factors limiting trade between countries. Considering the importance of dealing with climate change and the interest of countries in imposing climate policies such as imposing carbon tariffs, the present research evaluates the effects of imposing this policy under four scenarios of imposing carbon tariffs by the European Union, Japan, the United States of America and all regions. It has studied the production and trade in Iran’s target industries using the environment-oriented general equilibrium model of the Global Trade Analysis Project (GTAP-E). In this regard, the 141 countries and regions and 65 sectors in the GTAP10 data have been divided into 5 regions and 9 sectors according to the purpose of the research. The estimation of the model using RunGtap software shows that imposing the carbon tariff on energy intensive industries in Iran. According to the results of this study, in order to maintain and develop the export markets of energy-intensive industries, it is necessary to adopt the necessary measures to decarbonize the production process of the aforementioned industries, including the use of new technologies, incentive policies, and carbon pricing. Key words: carbon tariff, energy industries on Iran, production, trade, GTAP-E model.

The purpose of this study is to examine the relationship between corporate governance and capital formation using the financial development channel. According to the investigations, it was found that the direct impact of corporate governance on capital formation is unclear. The analysis of the data showed that corporate governance through the financial development channel can have an effect on capital formation, which, of course, is different in countries, and the reason for that is the different level of development of countries in attracting capital and investors. In this study, the data of 98 countries, including 67 countries in which investor protection is strong and 31 countries in which investor protection is weak during the years 2005-2020, were used in the form of Panel-GMM method. The results of the surveys showed that corporate governance in countries with a low level of investor protection has a positive and significant effect on capital formation, and improving corporate governance improves capital formation. But this relationship has not been significant for countries with a high level of investor protection. Also, financial development in both groups of countries had a positive and significant impact on capital formation, but its impact was greater in countries with weak support. Also, the results of the financial development survey in more detail showed that the financial development of markets improves capital formation in countries; But the financial development of institutions does not affect the improvement of capital formation.

The negative consequences of financial crises require the attention of economic policymakers and decision making centers.Therefore, considering the importance of the subject, the present study has investigated the effects of global financial crises on the trade patterns of Iran and its partners during the years 1995-2018.The variables have been estimated in the framework of the gravity model using the pseudo poisson maximum likelihood method.The findings show that the Asian financial crisis (1997) has an effective role in reducing the volume of trade but this result is the opposite in relation to the American financial crisis (2007) ; Because instead of a threat, it has become an opportunity for the movement of business flows. In this situation, it seems that the difference in the intensity and type of impact of financial crises on trade patterns can be affected by the nature of the crisis or the region where the crisis started.

There have been many studies on economic sanctions and the effectiveness of these sanctions. In these studies, the sanction variable treats as one or two dummy variables (binary), to indicate at most four levels (no sanctions-mild sanctions-severe sanctions-comprehensive sanctions). Studying the effectiveness of economic sanctions requires recognizing the extent and severity of sanctions in various sectors, so it is not possible to examine the effectiveness of sanctions and any review of economic sanctions independent of the severity and extent of sanctions. To this end, in this article, we present the severity of sanctions imposed on the energy sector to a variable between zero to five to provide a better indicator to understand the pressure of economic sanctions imposed on the energy sector of Iran. We examine the effectiveness of sanctions by entering the sanctions severity variable on Iran's foreign trade with five major trading partners, including Germany, China, India, United Arab Emirates, and Turkey, based on the gravity equation through an interactive dummy variable method. We tried to present all the sanctions imposed on Iran's energy sector, between 1992 and 2018. The results show a significant and negative effect of the intensity of energy sector sanctions on Iran's foreign trade. China and UAE have the lowest response to sanctions on Iran’s Energy sector. Also, the highest reduction of trade with Iran due to energy sector sanctions is dedicated to India and Germany.

Bank controllers and regulators have always focused on bank capital and capital adequacy rate as two important factors for sustaining and improving banking activities. In this research, we have tried to investigate the role of capital and the relations between the banking sector with the economic real variables. We also sought to study the impact of bank capital on the real sector of an economy, using the DSGE model. Accordingly, in this model, to comply with the facts of Iran's economy, we defined the capital adequacy rate based on Basel I and II standards and took into account the probability of default for the loans and facilities of the banks and firms endogenously. Meantime, since the banking sector plays a crucial role in the country’s economy, we tried to examine the relations between the banks and Iran Central Bank (CBI) as the regulator within Iran's economic ecosystem.

To examine the actions and reactions of key dynamics of the Iranian banking sector with the economic real variables, we used Dynamic Stochastics General Equilibrium (DSGE) model, by using quarterly modified data during 1996-2019.

The results of simulating the model in response to the bank capital increase and oil positive shock on the defined variables proved the designed model to be highly consistent with the theoretical expectations and the past experiences of Iran's economy. Furthermore, it was found that due to the increase in oil price and the positive balance of payment because of the increase in the oil income, bank loans could be increased. Therefore, by improving economic variables temporarily, oil positive shock would result in a decrease in the probability of default in banks, whilst increasing their profits. The results also indicated that the bank capital can be considered a key factor for evaluating real variables in Iran's economy by the CBI, so the increase in bank income would temporarily end in a decrease in GDP, because of different factors, including the cost of bank finance and the loan rate.

It can be concluded that capital plays an important role in the bank transition mechanism to society and the Central Bank can also play an important role in the process through applying the needed changes in the capital adequacy rate. Nevertheless, as the increase in the capital adequacy rate in the long term would decrease risk and improve banking activities, it would affect real variables during the transition period. Furthermore, any increase in liquidity and bank loans would decrease the real interest rates, affecting the economic variables positively. In addition, the effects of any increase in oil income can be shown in bank profit. Therefore, oil shock changes can be generalized to other economic real variables.

The present study, in the form of a state-dependent model and during the period 2001:6-2019:12, investigates which of the components of monetary aggregates has the greatest impact on real exchange rate volatility of Iran. In order to achieve this goal, the variables of money, quasi-money, liquidity and monetary base are considered as monetary aggregates and in order to avoid multicollinearity between monetary aggregates, four Markov Switching Exponential GARCH models with fixed transition probability are estimated. The findings of the study also indicate that in both low and high regimes of real exchange rate volatility, monetary aggregates have a positive and significant effect on real exchange rate volatility and the effect of monetary aggregates in low regime of real exchange rate volatility is different from the high regime, so monetary variables have an asymmetric effect on real exchange rate volatility. In addition, in both the low and high regimes of real exchange rate volatility, the monetary base had a greater effect on real exchange rate volatility than other components of monetary aggregates. Therefore, controlling the components of monetary aggregates, given the importance of each in the up and down state of real exchange rate regime, can be considered as a strategic point by economic policymakers.

This article examines the non-linear effect of inflation on the economic growth of Iran, Algeria, Saudi Arabia and Nigeria. So far, there have been many studies in the field of economic growth, in which different estimation methods have been used. The dependent variable of this research is GDP per capita as an indicator of economic growth, and the variables of inflation rate, investment, labor force, income from oil export and government expenditure have been used as explanatory variables. In the current study, using the non-linear distributional autoregressive model (NARDL) with the bound approach, the effect of inflation rate on the economic growth of the countries under investigation has been investigated asymmetrically. In this project, the positive changes in the inflation rate are shown with the POS variable and the negative changes in the inflation rate are shown with the NEG variable. The research period is 1990 to 2019 and the data are annualized. The results of Curran's test indicate the existence of a long-term relationship between research variables. The results in the case of Iran show that the variable coefficient of NEG is negative and significant, and the variable coefficient of POS is meaningless. In the case of Algeria, both coefficients of NEG and POS variables are negative and significant. For Nigeria, POS variable coefficient is negative and significant, but NEG variable coefficient is meaningless. Therefore, for all three countries of Iran, Algeria and Nigeria, the effect of inflation rate on growth is negative and due to the different coefficients of NEG and POS variables, this effect is non-linear. In the case of Saudi Arabia, both coefficients of POS and NEG variables are meaningless.

The economy of many countries around the world is now dependent on commercial activities in ports. Although ports are considered among the most important transportation infrastructures that can greatly affect economic growth, less attention is paid to ports and their relevant commercial activities in Iran. This study used the mixed-data method to address this issue by reviewing the data related to Khuzestan, Bushehr, Hormozgan, Sistan and Baluchestan, Guilan, and Mazandaran provinces of Iran in the period 2005-2017. The results showed that the operating capacity of ports exhibited a significant and positive effect on the economic production of the studied provinces. In addition, the uploading and offloading volume showed a significant but nonlinear effect on the economic production of hosts. In other words, the economic production increased with the increase in the operating capacity of ports but further increase in the operating capacity beyond the critical point negatively affected economic production. The study findings also indicated that human development, economic growth rate at the beginning of the studied period, employment, government investment in ports, government’s working budget, technology, manufacturing structures, and urbanization rate had positive and significant effects on the economic production of the studied provinces.

The purpose of this article was to investigate the replacement of traditional money with virtual currencies and its effects on macroeconomic variables with the approach of Dynamic Stochastic General Equilibrium (DSGE) models. For this purpose, the data of the period 2018-2019 with seasonal frequency have been used. In the model designed in this article, it is assumed that due to the use of virtual money, a substitution between virtual money and traditional money will happen in people's asset portfolio. In this study, the shock caused by the price and volume of Bitcoin transactions is considered as an indicator for the demand for virtual currency. The results show that the shock from virtual currencies has led to a decrease in the demand for traditional money, in other words, there has been a substitution between holding traditional money and virtual money. In addition, the results indicated that due to the shock of virtual currencies, the amount of consumption in the economy has increased, and on the other hand, the amount of government income from royalties and money printing has decreased. Also, the results showed that the government's tax revenues have also decreased due to the trend of financial resources in the economy towards the demand of virtual currencies.