تیمور محمدی

High tax rates and tax burden are one of the most important causes of tax evasion. In addition, the tax burden caused by the increase in the tax rate leads to an increase in the activity in the underground economy sector, which in turn will increase tax evasion. Studies show that the amount of tax evasion in Iran is high and tax is one of the important and influencing factors. Based on this, the present article investigates the asymmetric effects of tax burden and production on Iran's tax evasion using the NARDL nonlinear model for the years 2014-2014. To calculate the amount of tax evasion, Tanzi's money demand method is used, which according to the estimation results of the model, with the increase of real per capita income and interest rate, the ratio of money volume to liquidity increases. Also, the asymmetric positive and negative effects of the tax burden have also led to a decrease in the ratio of money volume to liquidity. Therefore, to solve the problem of tax evasion in Iran, one of the most important solutions is the growth and development of the production sector.

The need to apply the requirements of the Basel III agreement in order to improve the performance of the banking system in the country and reduce the effects of the risks facing this sector, prompted this study to investigate the level of implementation of the Basel III guidelines and their effect on the performance of the banking system in Iran. In this regard, this research using the information obtained from the annual financial statements of 16 sample banks, including Bank Ekhtaz Novin, Parsian, Tejarat, Sina, Saderat, Kerebehan, Mellat, Post Bank, Saman, Pasargad, Day, Shahr, Tourism, Capital , the future and the Middle East for the annual period from 2013 to 2021 studies the state of the banking system in Iran. This research uses DID models to carry out the aforementioned investigation. Empirical findings showed that in the presence of the requirement of stable net investment ratio, bank size has a positive effect on the bank stability index. This is also true for the ratio of cash to property. However, the effect of net profit-to-equity ratio and liquidity (liquidity) on bank stability is negative, assuming the At the level of 5% effect of bank size, net interest to equity ratio, cash to asset balance, liquidity and capital flight under the conditions of 8% capital ratio requirement have a significant effect on the stability of the banks under the conditions of applying the 8% capital ratio requirement.requirement of stable net investment ratio.

Global greenhouse gas emissions have risen from 31,553 million tons of CO2 equivalent in 1990 to 46,187 million tons in 2022. According to the United Nations Intergovernmental Panel on Climate Change (IPCC), since the late 19th century, the Earth’s average temperature has increased by 1.1 degrees Celsius.Every decade since 1960 has been warmer than the previous one, with the last decade being the hottest on record. The warming caused by human activities and greenhouse gas emissions has currently reached about 1 degree Celsius above pre-industrial levels. Over the past two decades, global scientific and political communities have increasingly focused on the issue of global warming and its associated climate changes. The historic Paris Agreement, signed on December 12, 2015, during the 21st Conference of the Parties (COP21) to the UN Climate Change Convention, was a significant step toward combating climate change and addressing the challenges of reducing emissions and investing in a low-carbon, resilient, flexible, and sustainable economy. The agreement, signed by 195 countries, came into force on November 4, 2016. Under the Paris Agreement, countries committed to reducing greenhouse gas emissions to prevent the global average temperature from rising more than 2 degrees Celsius above pre-industrial levels, and to pursue efforts to limit the increase to 1.5 degrees Celsius above pre-industrial levels.Following the agreement, countries through the UN Climate Change Convention asked the IPCC to provide a special report on the impacts of global warming of 1.5 degrees Celsius above pre-industrial levels and related global greenhouse gas pathways. In the IPCC report, supported by 133 researchers, various greenhouse gas emission pathways to achieve the 1.5-degree goal were outlined. Achieving this goal will require significant reductions in greenhouse gas emissions, with a major focus on the energy sector. Four proposed scenarios, which aim to reach net-zero carbon emissions by 2050, predict a sharp decline in the use of fossil fuels. However, the type of fuel and the speed of the transition in fuel consumption vary considerably, especially for coal, oil, and gas, through 2030. Coal faces the most severe reductions, with consumption needing to decrease by 59% to 78% by 2030 compared to 2010. Natural gas has a better outlook, with predictions ranging from a one-third increase to a one-quarter decrease in different scenarios. Oil has the most uncertain future, with the fourth scenario, based on bioenergy combined with carbon capture and storage (BECCS), predicting an 86% increase in oil consumption compared to 2010. Given the uncertain future of oil in these scenarios, analyzing the impact of implementing each of the IPCC's proposed scenarios on OPEC member countries, whose economies are heavily reliant on oil revenues, is crucial. The innovation of this research lies in examining the effects of climate change policies on oil-producing and exporting OPEC countries, including Iran, using a time-series econometric approach, co-integration equations, and a vector error correction model.

Methods and Material:

In this research, to examine the effects of the IPCC scenarios, which are based on reducing global fossil fuel consumption, on OPEC’s oil demand and supply, a time-series econometric approach was used. Co-integration equations were employed to estimate long-term relationships, and the vector error correction model was applied for short-term estimates. Given the significance of reduced demand for OPEC countries, which are economically dependent on oil export revenues, data on the production and price of OPEC oil were used. Additionally, the long-term effects of environmental actions under the IPCC scenarios, which replace fossil fuels with renewable energy by 2030 and 2050, were incorporated into the model using renewable energy price variables. Variables used in the supply and demand functions include OPEC oil production, OPEC oil prices adjusted for the U.S. consumer price index, industrial production indices for developed and emerging countries, and renewable energy price indices. The research data were gathered monthly from 1986 to 2022. OPEC oil price and production statistics were obtained from OPEC, and the U.S. consumer price index data were sourced from the World Bank. The industrial production index (IP) for developed countries was calculated as a weighted average of IP from the U.S., Japan, Germany, France, the U.K., Italy, Canada, Spain, the Netherlands, Sweden, Norway, Belgium, Austria, Denmark, Finland, Greece, Ireland, Portugal, and Luxembourg, with weights based on the GDP share of each country in total GDP. For emerging countries, the IP index was similarly calculated for China, Brazil, India, South Korea, Mexico, Turkey, and Indonesia. The GDP data were obtained from the World Bank, and IP data from the International Monetary Fund. Renewable energy prices were based on the weighted average levelized cost of energy (LCOE) for renewable sources such as concentrated solar power, offshore and onshore wind power, and photovoltaic solar energy. The weights were based on each energy type's share of total renewable energy production, and the LCOE data were published by the International Renewable Energy Agency. Initially, the industrial production indices for developed and emerging countries, as well as the renewable energy price index, were seasonally adjusted.

OPEC adopts two approaches in the global oil market: a strategic approach, where OPEC acts similarly to non-OPEC producers and amplifies the effect of price shocks, and an adaptive approach, where OPEC seeks to balance non-OPEC production changes and stabilize oil price fluctuations. The estimated coefficients indicate that during the study period, OPEC countries, alongside the increase in non-OPEC production, attempted to maintain their market share, often increasing production to force high-cost producers out of the market. This finding is consistent with those of Bog, Pal, and colleagues (2016), who viewed OPEC as a dominant producer seeking to protect market share by limiting competitors like shale oil producers.The results of the model estimation indicate a direct relationship between OPEC oil supply and real oil prices, with a price elasticity of oil supply of 0.22. Additionally, a 1% increase in non-OPEC production leads to a 1.56% increase in OPEC oil production. The price elasticity of oil demand is negative at -0.05, with demand from developed countries having a more significant impact on OPEC oil demand than demand from emerging countries. Furthermore, a 1% decrease in renewable energy prices reduces OPEC oil demand by 0.26%. Therefore, in the pessimistic IPCC scenario, where oil consumption declines by 37%, OPEC’s oil supply could decrease by 40% by 2030.Based on the findings, it is recommended that OPEC regularly monitor the pace of renewable energy development up to 2030 and adjust its strategies accordingly. Although the growth of industrial production in developed countries has a more significant effect on OPEC oil demand, trends in oil imports from China and India, which accounted for about 40% of OPEC’s exports in 2019, versus declining imports from the U.S. and European OECD countries, which have dropped by 40%, should also be considered by OPEC.

insurance linked securities as a financial derivative are one of the common tools in the financial economy that risk management specialists in the insurance industry use with the purpose of financing and transferring risk to the capital market. Nevertheless, despite the fact that these bonds have been in use in the global financial markets for more than 30 years, in Iran, due to the lack of infrastructure, some ambiguities in interpretation, the complex and technical nature of insurance operations, and as a result The complexity of ILS bonds, this financial instrument has not been used in the insurance industry. On the other hand, with the start of sanctions on the insurance industry since 2009 and the withdrawal of brokers and reinsurers from the country's insurance industry, it was not possible to transfer large and catastrophic risks outside the geographical borders of Iran, and this risk accumulation In the country, the risk of bankruptcy of insurance companies has increased in the event of a major and catastrophic accident. Based on this, in this article, using Markov-switching approaches, value at risk (VAR) and scenario building, the design of excess damage coefficient bonds as one of the types of ILS bonds in the field of fire and It has been paid in the country's insurance industry. Based on the findings of this study, it can be said that the papers designed in this study meet three conditions; Guaranteeing the principal of the buyers of ILS bonds (with the aim of solving the jurisprudential problem), the expected return higher than the risk-free return rate in the market, as well as the attractive premium rate (proportion between the commitment limit and the premium rate), can be the basis for issuing these bonds in provide Iran's capital market.

In recent years, the popularity of investing in cryptocurrencies has increased, and gradually, the cryptocurrency market has matured by attracting higher liquidity and developing online trading platforms. However, investing in this area can disrupt the balance between risk-adjusted returns due to sudden price fluctuations. To address this issue, selecting an optimal portfolio that simultaneously maximizes expected return while minimizing investment risk is crucial. Accordingly, this study aims to select an optimal portfolio of cryptocurrencies using the Conditional Value at Risk approach and the Markov Switching GARCH process. For this purpose, daily return data from six high-market-cap cryptocurrencies—Bitcoin, Ethereum, Litecoin, Ripple, Cardano, and Binance Coin—as well as the stablecoin Tether—were utilized from January 1, 2019, to December 1, 2023. The study results indicate that in a high-volatility regime, a larger portion of the investment portfolio is allocated to the stablecoin Tether and Bitcoin (which exhibit more stable price movements than other cryptocurrencies). Conversely, in a low-volatility regime, the optimal investment portfolio allocates a higher weight to altcoins, aiming to maximize expected returns.

Validity of a policy to achieve the goal of sustainability is an important issue. Stability of expectations through monetary policy is successful when financial policies do not make expectations unstable. The coordination between monetary and financial policies is done at two different levels, firstly in the short term and in accordance with the conventional performance of monetary and financial policies, and secondly regarding the long-term effects of macroeconomics, which can affect the coordination of unadjusted policies. In the short term, coordination is a policy to achieve financial goals, including price stability. The main focus should be placed on monetary policies and government debt management. In the long term, the issue of policy coordination is adjusted based on how to design the structure of monetary and financial policies, which leads to maintaining the path of economic growth in a balanced way; that is, it controls inflation and provides financial conditions for sustainable growth. This indicates that the financial deficit should be limited to such an extent that the capital market can operate without disturbing the allocation of resources in the economy and bringing the need for the central bank. Considering the continuous budget deficit, one of the most important economic challenges in Iran is the dependence of the government budget on oil, because the more the dependence of the government budget on oil revenues and its influence on oil impulses, the more fluctuations in the demand of the entire economy. The importance of the mentioned issue stems from the fact that increasing government spending has been one of the ways to achieve greater economic growth in recent decades, but this has caused governments to face the problem of continuous budget deficits. On the one hand, the government's income has serious limitations due to the weakness of the tax system and some economic structural problems. On the other hand, the adoption of incorrect financial policies and lack of proper planning along with population growth lead to an increase in demand for public goods such as education and health. This has led to the increasing growth of government expenditures. The limitation of the government's resources and incomes causes a budget deficit, making governments borrow from the central bank to cover this deficit. The monetary authorities' reaction to this issue can be effective in the stability of economic policies.

Monetary and financial policies have always been of interest to economists as tools to achieve macroeconomic goals. Of course, there have been fluctuations in focusing on the positive role of each of the economic policies in stabilizing economic fluctuations. The main goal of this research was to examine the relationship and coordination between monetary and financial policies in Iran's economy. For this purpose, the statistical information of the period 1989-2022 was used based on the frequency of the seasonal data. In order to model the interaction and relationship between monetary and financial policies in Iran, the Dynamic Stochastic General Equilibrium (DSGE) model was used.

Based on the results, the shock of monetary policies initially has a very decreasing effect on economic growth and consumption. From the fourth period onwards, however, the impact of monetary policy shocks on these two variables is positive. This can be due to the existence of unsupported monetary policies in the country and the resulting increase in inflation, which has a negative impact on consumption and economic growth. As a result of the monetary policy shock, the net investment increases sharply at first and reaches a maximum in the fourth period and then decreases with a downward trend. Therefore, due to the effects of inflation, monetary policies lead to the desire of households and companies to increase investment. In the case of government spending, the monetary policy shock increased the government spending sharply at first and, after six periods, it went through a relatively downward trend with a gentle trend. According to the results, financial policy shocks have first led to an increase in consumption and economic growth and finally to a decrease. As a result of the financial policy shock, the net investment decreases sharply until the sixth period and reaches zero. After that, it increases mildly. Also, in response to the financial policy shock, there is an increase in the inflation rate and the amount of money in response to the financial policy shock. This indicates the supremacy of financial policy over monetary policy in the country.

Conclusions and policy implications: 

In Iran, monetary and financial policies are always implemented by policymakers with the aim of creating economic growth and stability. But, unfortunately, there is always the issue of deviation from the goals and the undesirable and negative welfare and economic effects of applying such policies. It seems that most of these issues are due to paying attention to monetary and financial goals separately rather than dealing with the interactions of those policies and, most importantly, recognizing the goal of preparing executive programs for these two areas. On the other hand, the dominance of financial policy and lack of attention to monetary and financial policy interactions have limited the power of the central bank to use monetary instruments to control inflation. It is necessary to study the interaction of monetary and financial policies, both from the point of view of economic considerations and with regard to the requirements of revising the implementation of those policies in terms of the negative effects on the economy caused by the implementation of wrong policies in the economy of Iran. According to the results, it is suggested to control the inflation rate and money growth in the country with the financial discipline of the government and the reduction of financing the government expenses from the area of money creation. In the end, non-violation of the announced policies by the policy makers will be the most important factor in reducing the financial indiscipline of the government.

Estimation of the optimal unemployment rate in accordance with the full employment of the labor force in Iran's economy for the years 69 to 1400:Achieving full employment as a long-term goal has been emphasized in the system's twenty-year vision document, and for this purpose, part of the goals, policies and measures of the country's development programs should be in accordance with the labor market goals in the vision document. to measure In this research, the estimation of the optimal unemployment rate corresponding to the full employment of the labor force in the economy of Iran for the years 1369 to 1400 was discussed. In this way, first the expected inflation rate was estimated and then the natural unemployment rate (NUR) of Iran's economy was estimated at 10.1 and the optimal unemployment rate was estimated at 7.65. Therefore, if Iran's economy is in the best condition and if the favorable conditions for the variables influencing the unemployment rate are imagined, then the unemployment rate will be lower than its natural unemployment rate. In order to reach the optimal unemployment rate, it is necessary to consider measures in the field of labor force employment. For this purpose, increasing economic growth and creating new job opportunities to create employment and employ educated and university personnel and adopting policies to improve foreign trade means using foreign capacities to export domestic goods and services and in contrast to using the capacities of Importing knowledge and technology with the aim of increasing domestic production capacity (along with increasing the scale of production) should be the key focus of the country's economic policy.

In recent years, processes with long-term memory have played substantial role in time series analysis. The existence of long-term memory in assets return time series has momentous applications in examining market efficiency, investor’s behavioral logics, pricing, and asset portfolio selection. In present study, using the AutoRegressive Fractionally Integrated Moving Average model (ARFIMA) and the Fractionally integrated generalized autoregressive conditional (FIGARCH) and hyperbolic GARCH (HYGARCH) models to investigate the existence of long-term memory in the Tehran Stock Exchange's main index (TEPIX) and exchange rate ( US dollars) in using daily data during the period Novamber, 2011 to July, 2023. The results indicate the existence of long-term memory in TEPIX and exchange rate (US dollar) is confirmed in ARFIMA model in both ML and GLS approaches and in GARCH family models in both FIGARCH and HYGARCH models. According to these results, price behavior in each of the mentioned time series is a function of the past amounts.

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.

The effect of income on subjective well-being, often used as a key measure of well-being, has been widely studied. However, various dimensions of this relationship remain unexplored. The current study aimed to examine the nonlinear effect of income on the subjective well-being of 58 countries over during 2005–2020. The analysis relied on two distinct scenarios. The Panel Smooth Threshold Regression (PSTR) model, derived from regime-switching models, was employed for the analysis. Additionally, the study investigated the effects of income, unemployment, inflation, life expectancy, and income inequality on subjective well-being. The findings revealed that in a nonlinear relationship, the effect of GDP on subjective well-being diminishes at a certain threshold value of income inequality. Consequently, while policymakers aim to increase national income and reduce income inequality to enhance well-being, it is crucial to recognize that further reductions in inequality beyond a certain threshold may reduce the effect of income on well-being. This suggests that after a certain threshold, governments should prioritize reallocating resources toward other essential needs rather than solely focusing on reducing income inequality.

The present article explains the asymmetric effect of tax burden and production on Iran's shadow economy using the NARDL nonlinear model for the years 2005-2021. In this research, the Tanzi approach of the demand function (money) has been used to estimate the size of the underground economy. The index of the underground economy in Iran has ups and downs during the period under review, and this trend has been increasing in the years 2014 to 2015. In recent years, paying more attention to the issue of tax revenues, tax transparency and the reduction of oil revenues of the government, the size of the underground economy has gone through its downward trend. Also, according to the results of the model, the asymmetric positive and negative effects of the tax burden lead to a decrease in the ratio of money to liquidity, which results in an increase in the volume of the underground economy. High tax rates and tax burden are one of the most important reasons for the increase in the size of the underground economy. A higher tax rate and tax burden will lead to increased activity in the underground economy sector, which in turn will increase the size of the underground economy. When the tax burden increases due to the increase in the tax rate, people move towards the underground economy faster, but the reduction of the tax burden will probably have a small impact on the underground economy. To solve the problem of the underground economy, one of the most important solutions that was examined in this research is the growth and development of the production sector. The government should have continuous planning for the improvement and growth of production and the continued growth of production for many years will result in the reduction of the underground economy.

This research investigated the effects of oil revenue decreases as a non-linear model based on Threshold Vector auto-regression(TVAR), with an emphasis on Iran’s sanctions during the period of 2003–2021 with seasonal data.  Real oil revenue growth was selected as a threshold variable; during the two regimes, the threshold was selected as -0. 021 for oil revenues, and by the generalized impulse response functions(GIRF), the effects of oil revenue increases on economic growth were investigated.  Results revealed that shocks of oil revenue in upward and downward regimes had different effects on economic growth rates.  The effects of shocks of oil revenue on economic growth in a downward regime were positive until the second period, and after that, they decreased, and after the sixth period, the economic growth was negative.  And in the upward regime, it was positive, and after the first period, it decreased at a lower rate than in the downward regime and finally tended to zero.  Finally, it can be concluded that the effects of oil revenue decreases on economic growth rate were more in the downward regime than upward, revealing that sanctions and decreases of oil revenue have a great impact on reductions of production and economic growth.  Therefore, it is recommended that the government, by implementing true politics and economic programs in line with the reduction of sanctions, reduce the sanctions' effects on production and economic growth.

Considering the intermediary role of banks in the economy and their critical function in the propagation of economic shocks to the real sector, this study aims to investigate the role of bank capital in analyzing the relationship between banks' balance sheet characteristics and economic fluctuations using a Dynamic Stochastic General Equilibrium (DSGE) model. The results demonstrate that, in the model with a bank capital channel, positive shocks lead to more robust economic growth. This is attributed to the banks' ability to invest, enhancing the positive effects of shocks. Taking bank capital into account, variables such as consumption, and inflation exhibit better performance, with reduced fluctuations or quicker adjustments, leading to economic stability. Conversely, in an economic scenario without a bank capital channel, positive shocks have a lesser impact on economic variables. Consequently, the results can effectively inform decision-making regarding the necessity of adhering to bank capital adequacy ratios.

For policymakers, researchers and investors, the price of crude oil is one of the most important factors affecting all economic factors such as inflation rate, economic growth rate, gross domestic product, foreign exchange income, etc. The exchange rate is not simple. Based on this, in the present study, the impact of global oil supply and demand impulses on the exchange rate of oil exporting countries has been investigated, emphasizing the special situation of Iran. The statistical population of the present research is 8 countries of Saudi Arabia, Russia, America, Kuwait, Nigeria, Libya, Iran and Oman, which have the highest oil export ranking in 2022, during the period of 2001 to 2022. In order to analyze the data, SVAR structural vector autoregression method and MS Markov switching model method were used. it was found that in all the studied countries, the impact of oil supply shocks on the exchange rate in the selected oil exporting countries was significant. Also, the impact of oil demand shocks and specific oil demand on the exchange rate was significant. Finally, it was observed that in the studied countries, the impact of total demand shocks on the exchange rate was greater than the total supply.

Resolving problems resulting from stagflation conditions accompanied with low economic growth and slow employment growth needs some policies that one of them can be unconventional monetary policy. Thus, this paper proposes to evaluate the effects of unconventional monetary policy shocks using VAR with a new method called sign restrictions. To this aim, it were estimated the effects of three variables ordered as real interest rate, inflation and gross domestic product by imposing positive and negative restrictions on these variables for the period 1961-2021. In this paper, the results of model estimation and impulse response functions is done by identifying and estimating parameters on the basis of imposing negative sign on interest rate according to unconventional monetary policy shocks. Results indicate that decreasing in interest rate causes increasing in GDP. Unconventional monetary policy can raise liquidity in stock market. It also support people by low interest rate loans for production with less cost and less sale price in Iran. Therefore, unconventional monetary policy can be a useful policy for resolving stagflation occurred current years in Iran.Extended Abstract:IntroductionThe global financial crisis(GFC) marked the transition from what many had labelled the period of “Great Moderation” to that of the “Great Recession”. The stress experienced by the financial sector starting in the summer of 2007 put an end to several years of robust growth for the world economy accompanied by moderate inflation rates across most advanced market economies. Across a number of countries, financial intermediation halted, with the peak of the stress manifesting in the final quarter of 2008. Unemployment increased and inflation dropped below central banks’ target levels as economic activity receded sharply. The recovery from the deep recession was also slow in many jurisdictions, with tepid economic growth, sluggish employment growth and subdued inflation. The challenges posed to monetary policy during this period were severe and pushed central banks to resort to actions departing from their established policy frameworks.The set of policy interventions introduced during this period has been labelled as unconventional monetary policy in order to distinguish it from the conventional pre-GFC policy measures. Some unconventional monetary policies were designed to affect term spreads such as long-term risk-free rates, while others were directed at influencing liquidity and credit spreads such as interest rates on various non-risk-free instruments. One of the most important tools in unconventional monetary policy is negative interest rate policy (NIRP). The adoption of negative policy interest rates in the aftermath of the GFC was new. Identification of shocks is one of the most important issues in econometrics for interpreting their impact on themselves and also other variables. Therefore, in case of unconventional monetary policy, VAR model is applied for identifying shocks. In the research, it was identified different shocks using sign-restriction approach in Iran for the period 1961-2021.

The use of fiscal policies with an impact on the gross domestic product allows governments to step in the direction of economic stability by reducing or increasing production in the necessary conditions. However, the effectiveness of fiscal policy is one of the most controversial topics among economists and researchers. The government spending multiplier is one of the things that determine the effectiveness of fiscal policy, and according to the changes in the parameters of the economic model over time, the estimation of the government spending multiplier over time is very important for the effect on the economy. Therefore, in this paper, the estimation of the government spending multiplier in Iran's economy with the TVP-FAVAR with seasonal data is discussed. The results show that the size of the government spending multiplier fluctuates between the values of 0.63 and 2.3 in the investigated time period. Most of these changes are caused by cyclical factors of the economy. On the other hand, structural factors play a minor role in the results. Therefore, according to the findings of the research, for the effectiveness of fiscal policy, more attention should be paid to the state of the economy in business cycles than other factors

Housing price shocks of one region may spread to the housing market of neighboring regions or geographical areas bounded by political border and lead to the formation of price shocks in shock-receiving areas. The housing policies may not be effective when implemented regionally and separately if there is a confirmed network connection between the housing markets of regions. Price shocks to a housing market spreads with a delayto interconnected housing markets, ultimately resulting in the diffusion of the price shock across the entire of the housing network. This researchaims to investigate the housing network between selected cities (centers of the country's provinces) using the VAR model and Forecast Error Variance Decomposition (FEVD). The results of this research confirm the existence of a network connection between the housing markets of the country's provinces, and unlike previous studies, the results show that it is not only the city of Tehran that spreads price shocks to other regions, but also cities such as Karaj, Shiraz, and Arak spread price shocks to other cities. In addition, the results suggest that the recent price jump, since 2019 has significantly increased the density of the housing network in the country. Based on this, price shocks are expected to be distributed more quickly throughout the country.

Considering that cryptocurrencies exhibit commodity characteristics such as demand shocks, high price fluctuations, etc., cryptocurrencies can be compared with the behavior of the gold and oil markets (except when there is uncertainty about the supply conditions of gold and oil. There is no such uncertainty in the cryptocurrency market). Therefore, due to the commodity nature of Bitcoin, the price of oil and gold can affect the price fluctuations of cryptocurrencies. It seems that cryptocurrencies can play the role of a safe haven for commodity market investors, so the cryptocurrency market can cover the fluctuations in gold and oil prices. Commodity markets, which this study focuses on gold, oil and cryptocurrencies, have a series of characteristics. It seems that the gold market has surpassed the cryptocurrency and oil market in absorbing information, while the cryptocurrency market has higher price fluctuations than the gold and oil markets. Empirical evidence shows that Bitcoin can have a close relationship with the commodity market.Therefore, due to the commodity nature of Bitcoin, the price of oil and gold can affect the price fluctuations of cryptocurrencies. رمزپایه تاثیر بگذارد. Therefore, due to the commodity nature of bitcoin, the price of oil and gold can affect the fluctuations of the price of crypto-currencies. 

THEORETICAL FRAMEWORK:

Every person in the financial markets who has an asset portfolio tries to increase or maintain the value of his asset portfolio. The position of each asset in the portfolio has two characteristics: return (price change) and risk (price volatility). The behavior of asset portfolio owners is such that they try to increase returns and reduce risk. In this framework, they buy or sell assets in their portfolio in order not only to prevent the value of their asset portfolio from decreasing, but also to increase the value of their wealth. This behavior of the capital owners leads to the creation of connections between the global markets, including oil, gold, and cryptocurrencies, so that their yield fluctuations are connected to each other through the risk spillover effect. The asset allocation models have been investigated in a practical way for about half a century. The most well-known asset allocation model is the mean-variance strategy (modern portfolio theory), which was first developed by Markowitz (1952) to describe the process of optimal capital allocation, assuming a fixed investment opportunity set, between different asset groups over a period.

In this study, the VAR− MGARCH − GJR – BEKK model has been used in order to investigate the asymmetric effects of turbulence spillover between the oil, gold and bitcoin markets because of the following advantages. First, this model has high flexibility. Second, in this model, unlike constant conditional correlation (CCC) models, the conditional correlation changes over time. In addition, it is possible to check several markets at the same time. The existence of the covariance equation makes it possible to examine the simultaneous relationship between two markets. In the BEKK model, the fluctuations of a market are affected by the fluctuations and shocks of other markets, the shocks of that market and the covariance of the markets. In other words, the effects of the markets on each other, which is reflected in the delayed covariance, have an effect on the fluctuations of the markets. These effects can be symmetrical or asymmetrical. Also, this model makes it possible to have a dynamic dependence between the fluctuations of the variables. The only disadvantage of this model is that it is not suitable for examining more than three or four markets due to the increase in parameters.

The results indicate that the contribution of the memory of turbulence in explaining the current turbulence is greater than the impact of past shocks. The impact of past impulses and the memory of the turbulences of cryptocurrencies is high on the turbulences of this market. In other words, it can be said that fluctuations in the cryptocurrency market are significantly explained by the past impulses of this market. The results show that there is one-way turbulence spillover from the Bitcoin market to the gold market and the oil market, but the opposite is not true. The results of the study also indicate leverage effects in the markets. The leverage effects of the gold market shock along with the oil and bitcoin market shocks on the gold market are significant. The leverage effects of the oil market shock along with the gold and bitcoin market shocks are also significant on the oil market and the leverage effects are also significant for the bitcoin market.The results of the study indicate leverage effects in the markets, in other words, positive and negative shocks have different effects on price fluctuations, and bad news has a greater effect than good news on price fluctuations.The results of the study indicate leverage effects in the markets, in other words, positive and negative shocks have different effects on price fluctuations and bad news has a greater effect on price fluctuations than good news.Can't load full.

The occurrence of a price bubble in the financial sector, especially the stock market and the possibility of its collapse, causes uncertainty about the financial market and ultimately the outflow of capital from it. Since the occurrence of crisis in these markets can affect other sectors of the economy as well, the policymakers plan and implement appropriate monetary and fiscal policies to deal with the crisis and respond in a timely and correct manner to prevent its destructive effects. Considering that Iranian financial markets, like other countries, are not safe from this phenomenon, in this research, by using Iranian quarterly data of some variables including interest rate, gross domestic product, gross domestic product deflator, dividends, consumer price index, oil price, exchange rate and stock price index, for the period 2003:1 to 2019:3 and Bayesian inference, the TVP-VAR model (time-varying parameters vector Auto regressive) is estimated and the impulse - response functions of variables is driven, and the dependence of stock market bubbles on monetary policy shocks are investigated. The results show that a number of research variables, such as interest rates, gross domestic product, gross domestic product deflator, dividends, stock price and it’s fundamental component, have had almost stable patterns over time, and their response to monetary policy shock has not changed much and only in the case of stock prices, we can see that its negative reaction to the monetary policy shock has decreased over time but the reaction of bubbly component of stock price to the monetary policy shock has not been stable over time and in recent years of the sample, the reaction of bubbly component, end up increasing  from the beginning.

Nowadays, due to the limitation of fossil fuels, the topic of their optimal use has been given more attention than before. In the upstream literature of oil and gas economy, the word synonymous with this topic is reservoir management. In this study, selected one of the oil fields of Iranian Offshore Oil Company (IOOC). In the first step, by using field data, the cost function of the field is estimated by considering the environmental costs and secondary recycling costs, and in the next Nowadays, due to the limitation of fossil fuels, the topic of their optimal use has been given more attention than before. In the upstream literature of the oil and gas economy, the word synonymous with this topic is reservoir management. This study selected one of the oil fields of the Iranian Offshore Oil Company (IOOC). In the first step, by using field data, the cost function of the field is estimated by considering the environmental costs and secondary recycling costs, and in the next step, the discounted profit of the field during its life under three discount rate scenarios, and it is maximized by dynamic programming method. The results of the bell curve study confirmed the production during the life of the field. Also, in the scenario of the discount rate of 5%, the harvest results from the field have been more balanced, and with the increase of the discount rate to 10 and then 20%, more harvest has been achieved in the first years of production and less harvest in the final years of productionstep, the discounted profit of the field during its life under three discount rate scenarios. and it is maximized by dynamic programming method. The results of the bell curve study confirmed the production during the life of the field. Also, in the scenario of discount rate of 5%, the harvest results from the field have been more balanced, and with the increase of the discount rate to 10 and then 20%, more harvest has been achieved in the first years of production and less harvest in the final years of production.

The negative correlation between an asset’s volatility and its return is known as leverage effect. This relationship is explained by the effect of a firm’s equity return on the degree of leverage in its capital structure. If this relationship holds, the increased volatility resulting from a fall in stock price should be comparable with the decreased volatility resulting from a price rise with the same magnitude, and this effect should also be persistent. Most research on the leverage effect has examined the relationship between the behavior of returns and return volatility. The present study aimed to examine the relationship between return volatility, returns, and the debt ratio. The data were collected from 22 biggest companies listed on the Tehran Stock Exchange for the period from March 2009 to March 2019. The value of debt in the capital structure of the selected companies was calculated using the Geske compound option pricing model. According to the results, the existence of an asymmetric effect on returns only during bearish market conditions, alongside the instability of this effect, indicates that the debt ratio cannot explain the behavior of returns and return volatility.

Economic uncertainty is a situation in which the future economic environment is difficult to predict, and there is a high degree of risk or unknown issues involved. This can be caused by a variety of factors, such as political instability, financial market volatility, or natural disasters. Economic uncertainty can have a significant impact on macroeconomic variables, such as GDP growth, investment, and consumption.Economic uncertainty can have a number of negative consequences for the economy. It can lead to a decrease in investment, consumption, and economic growth. It can also lead to an increase in inflation and financial market volatility. If there is a political crisis, businesses may become more cautious about making investment decisions, as they are not sure what the future holds. This can lead to a decrease in investment, which can dampen economic growth. Similarly, if there is a financial crisis, consumers may become more cautious about spending money, as they are not sure whether they will lose their jobs or their investments will lose value. This can lead to a decrease in consumption, which can also dampen economic growth.

As a basis for analysis, the stochastic dynamic general equilibrium (DSGE) model was used in this study. It is a type of economic model that combines elements of both microeconomics and macroeconomics. They are used to simulate the effects of economic shocks on macroeconomic variables. The DSGE model used in this study was based on Iran’s data from 1989 to 2022. The model was then used to simulate the effects of economic uncertainty shocks on a variety of macroeconomic variables, including GDP growth, investment, consumption, the exchange rate, the interest rate, and inflation.Since the central bank in Iran is not independent, it is not possible to model the government and the central bank as two separate parts, but these two should be considered in the same framework. The government tries to balance its expenses in the form of current and construction expenses through the revenues from receiving a lump sum tax from the household, the sale of partnership bonds and the income from the sale of oil. In fact, it is assumed that most of the banks are owned by the government.

The purpose of this study was to investigate the effects of economic uncertainty shocks on macroeconomic variables. The results indicate that the real variables of the economy such as investment, production, consumption, government spending, and taxes decreased in response to the shock of economic uncertainty. However, nominal variables such as the exchange rate, interest rate, and inflation rate increased in response to that shock.The results of the study suggest that economic uncertainty shocks can lead to instability in the economy. This is because economic uncertainty induces a decrease in economic activity, as businesses and consumers become more cautious about making investment and spending decisions. This can lead to a decrease in GDP growth, employment, and income.In addition, economic uncertainty can increase the inflation by making the demand for goods and services exceed the supply.

Conclusions and Policy Implications:

 The findings of this study suggest that economic uncertainty shocks can have a significant impact on macroeconomic variables. Policymakers should be aware of the potential negative consequences of economic uncertainty shocks and take measures to mitigate their impacts. This could include policies that promote economic stability, such as fiscal stimulus and monetary policy. By understanding the causes and consequences of economic uncertainty, policymakers and businesses can take steps to mitigate its negative impacts and promote economic stability.

Oil prices and other oil-products prices are connected and their price volatilities are parallel. Firms that are using crude oil in their products are facing the risk of price volatility which has different reactions in each era and is known under different oil regimes. When the economy faced volatility the market players faced loss and so to overcome this issue they began to hedge themselves with another commodity. This hedging process in different regimes has different rates. From the work of Hamiltonian (1989) oil price has its volatility and regimes so to this attitude there is an effort to find the effect of inflation and liquidity growth on efficient hedging ratios in different oil regimes. Monthly data of oil and gold prices for about 10 years from 2010 to 2020 is used and the model is programmed with MATLAB. The efficient hedge ratio for the first regime is 66 percent and the second one is 26 percent. In the periods when inflation and liquidity growth had an inappropriate trend, there was a lower grade for hedging oil prices with gold. There are two regimes for the price of oil which is for higher than 100 dollars and under 100 dollars and this historical situation happened in 2007 and 2009 either. In the period when the economy was experiencing high inflation and high liquidity growth, the optimal ratio of hedging decreased significantly, and in periods of low inflation, gold as a haven has been able to realize more optimal hedges..

Climate change is becoming a global crisis that can affect all aspects of human life on Earth, including the economy. So, protecting the environment and achieving sustainable development goals are now on the agenda of many governments. This article uses the Panel Smooth Transition Regression Model to test the role of information communication technology as a transition variable. In this research, it is investigated whether ICT can decouple the economic growth from the increase in pollution by changing the effect of productivity on CO2 emission. The goal is to show whether policymakers can use the development of the digital economy around the world to achieve better environmental and economic outcomes. This study was conducted on a global scale and data from 108 countries was used from 2003 to 2019. The results show that the co2 emission follows a PSTR model with ICT as a transition variable that changes the effect of total factor productivity on co2 emission in favor of the environment. ICT development will improve carbon efficiency and reduce climate change.

monitoring and measuring periods of financial instability became particularly important, and measuring financial stress has found a special place among policymakers and economic agents. Due to the nature of the banking system in the Iranian economy and the tight control of the government over it, although banking crises such as the banking invasion have never been observed in Iran, but the Iranian banking system has experienced crises at different times. In this study, with the help of bank stock prices, the stress index of the banking sector in the Iranian economy has been calculated and the factors affecting it in different oil price regimes have been identified. The results show that (1) the highest amount of stress in the banking sector is related to the winter of 1391 and spring and 1397 and the lowest amount of stress in the banking sector is related to the summer of 1390, winter of 1394 and spring of 1395.(2) In periods when oil prices are high, the variables of total banking system claims, total liquidity and private sector investment in new buildings in urban areas are stress drivers in the banking sector and in contrast to bank-reducing facilities. Stress is in this area