مجله سیاست گذاری اقتصادی
سال چهاردهم شماره 27 (بهار و تابستان 1401)

Taxes, as an effective policy of governments to achieve their desired economic, social and political goals, can affect the welfare of the society by influencing the production and distribution of income. However, different types of taxes do not necessarily have the same effect on social welfare, as they may have different welfare effects in terms of sign and magnitude. Accordingly, the question arises as what effect the substitution of different tax items and, thus, the change in the tax mix will have on the level of welfare. In other words, how does an increase in the share of each tax in the total tax revenue and, conversely, a decrease in the share of each of the other taxes of the same magnitude affect social welfare? Generally, if two types of taxes reduce or increase the welfare of the society, substituting one that has a smaller or larger effect for the other can improve the welfare. On the other hand, if two types of taxes have opposite welfare effects, substituting one that increases welfare for the other will eventually improve the welfare. Therefore, the choice of an optimal tax mix is of great importance for tax policies. In this regard, the main purpose of this study is to analyze the welfare consequences of substituting different types of taxes (including indirect tax, income tax, wealth tax and corporate tax) with the assumption of a constant government budget (i.e., budget-neutral changes in the tax mix) for Iran. This study employs an empirical model consisting of four regression equations, in each of which social welfare, measured by the Gini social welfare function proposed by Sen (1974), is considered as the dependent variable. On the other hand, the percentage shares of the four main tax categories in the total tax revenue that add up to 100 percent and a number of other key factors that potentially affect social welfare (i.e., inflation rate, the ratio of government consumption expenditure to GDP, and the degree of trade openness) are used as explanatory variables. However, one of the tax shares is excluded from each equation. In other words, three of the four tax shares and a common set of other potential determinants of welfare are included on the right-hand side of each equation. Given that the sum of the four tax shares is always equal to 100% and that the specification of the non-tax variables is the same in all the equations, the coefficient of each of the three tax shares included in each equation represents the effect of a one-unit increase (decrease) in that tax share and, conversely, a one-unit decrease (increase) in the tax share excluded from the equation on social welfare. The reason is obvious. Generally, each coefficient in a regression model signifies the change in the mean of the dependent variable per unit increase in the associated explanatory variable when all the other explanatory variables are held constant. On the other hand, since the sum of the four tax shares is equal to 100%, a one-unit increase (decrease) in one of the three tax shares included in each regression equation and the other two tax shares held constant mean a one-unit decrease (increase) in the tax share excluded from the equation. Finally, the regression equations are estimated separately using the autoregressive distributed lag (ARDL) approach and the data for the period of 1982-2018. In this study, firstly, social welfare is measured using the Gini social welfare function for the period of 1982-2018. The results show that the welfare of society has generally improved over the period of 1988-2011, but, since then, it has been accompanied by some fluctuations. In the next step, the Phillips-Perron test is applied to determine the order of integration of the variables under consideration. The results of this test reveal that the maximum order of variables integration in each of the four regression equations is 1, satisfying the necessary conditions to implement the bounds procedure based on the Wald or F-statistics in testing due to the existence of a long-run relationship among variables (i.e., co-integration testing). The results show that the null hypothesis of no co-integration is rejected for each of the models. Thus, the estimated ARDL model is used to solve the long-run relationship between the variables in each model. The analysis then proceeds based on such estimated long-run relationships (coefficients). The findings indicate that a) a one-unit increase in the percentage share of the income tax in the total tax revenue and, conversely, a decrease in the percentage share of the corporate tax of the same magnitude will improve social welfare, b) a one-unit increase in the percentage share of the income tax and, conversely, a decrease in the percentage share of the indirect tax of the same magnitude will improve social welfare, c) a one-unit increase in the percentage share of the wealth tax and, conversely, a decrease in the percentage share of the corporate tax of the same magnitude will improve social welfare, and d) a one-unit increase in the percentage share of the wealth tax and, conversely, a decrease in the percentage share of the indirect tax of the same magnitude will improve social welfare. In addition, substitutions (1) to (4) have the most to the least effect on welfare, respectively. Finally, other substitutions (i.e., substituting income tax and wealth tax with each other and substituting corporate tax and indirect tax with each other) do not have a significant impact on the welfare of the society. This study examines the effects of substituting different tax items (i.e., budget-neutral changes in the tax mix) on social welfare in Iran using the corresponding data for the period of 1982-2018. The empirical results show that a budget-neutral substitution of income tax or wealth tax for indirect tax leads to an increase in social welfare in the long-run. In addition, the budget-neutral substitution of income tax or wealth tax for corporate tax can improve social welfare in the long-run. These findings have important implications for reforming the country’s tax structure in order to improve the welfare of the society.

The exchange rate, as one of the macroeconomic factors, reflects the economic conditions of the country and is the link between domestic and foreign economies. It has a direct impact on the price of exports, imports as well as domestic prices. In the same vein, income is related to household consumption and affects the distribution of household income. Widespread inequalities in income distribution lead to the emergence of poverty and the creation of gaps among the social classes. When poverty is on the rise, it is inevitable to see a decline in the level of health, hygiene, nutrition and education of the people of the society and, consequently, economic productivity, economic growth, production and national income. This vicious circle leads to the aggravation of poverty. Inequality can undermine social cohesion, reduce intergenerational income mobility, and create challenges such as social discontent and political instability.Exchange rate through export prices (assuming the stability of the world export price based on foreign currency) affects economic variables. In this process, the price of a product is determined based upon the export prices and domestic prices. So, with export prices being on the rise, product prices increase. This will increase the price of the producer active in exportation and ultimately the household income. The influence of the exchange rate through the imported prices would be another factor that needs to be taken into consideration. According to such a mechanism, assuming that the world prices of the imported goods are constant, exchange rate fluctuations cause changes in the import prices (based on the national currency) that interact with the price of the domestic demand. It changes the price of composite goods. According to the aformentioned mechanism, it is expected that the increase in the exchange rate will increase the price of composite goods as the import prices increase. In this way, the value added decreases, and the reduced price of production will reduce household income. In general, it can be said that one of the most important ways in which a growing exchange rate affects household income and, consequently, household expenditure and welfare is the exertion of those two forces.

The purpose of this article is to investigate exchange rate shocks on income distribution using a general equilibrium model. The Computable General Equilibrium (CGE) model is a quantitative analysis method that is flexible in the face of a wide range of policy issues and can provide a holistic framework for examining the comprehensive effects of shocks. In addition, the robust micro-framework of general equilibrium models, which fully describes the optimization behavior of economic agents, allows these models to have stronger analytical foundations. General equilibrium models evaluate different economic policies and programs as well as the way of interaction and communication of different economic activities and different institutions in society in different markets. Those models address goods and services, labor market and the outside world in proportional linear and nonlinear forms. Therefore, they are highly able to predict the effects of implementing various socio-economic policies and shocks. The statistical basis of the research is the social account matrix in 2011 published by the Parliamentary Research Center. In this study, the distributive effects of 10, 20, and 30 percent exchange rate increases on income distribution were investigated. To investigate the heterogeneity of households, the parameters of the demand function derived from the Aston Gray utility function were estimated using the income and expenditure data of the Statistics Center of Iran, and then the effect of shocks on income distribution was investigated. Using micro-data on household income and expenditure, the segregation of the household sector in the model increased, and, based on the amount of the household expenditures, the households were classified into ten groups (using the typical middle household method and the integrated method). Then, the data obtained from the household budget studies were combined in the social accounting matrix, and the general equilibrium modeling was performed according to the new databases. Finally, the effect of the exchange rate change on the Gini coefficient was investigated.

As the simulation results showed, increasing the exchange rate from 10% to 30% reduced the average real consumption of urban deciles from 4.94% to 1.76% and, in rural deciles, from 4.57% to 1.15%. This effect was greater in urban households than rural households. It increased the Gini coefficient in both deciles. Also, currency shocks emerged as an important factor in explaining the level of inequality and income gap created between different income deciles. The impact of the currency shocks between urban and rural income deciles was not the same. The above shocks have caused a greater decrease in the level of consumption of urban income deciles than rural income deciles.  This difference in the intensity of response to currency shocks is much greater among the lower income deciles.

Since this article follows the relationship between the devaluation of the national currency and the income distribution of urban and rural households, the following suggestions are made so as to achieve policies that can neutralize the effects of currency shocks on income distribution.- Adopt the right approach by the central bank in managing the foreign exchange market and stabilizing the real exchange rate.- Reduce the country's dependence on the oil sector, import and increase the diversification of export products, and increase the share of the National Development Fund in oil revenues in order to reduce the effects of currency shocks.- Develop the financial sector of the economy. The results show that the more developed the financial markets, the less the effect of exchange rate shocks on income generation and distribution. In this regard, it is recommended that future research use a general equilibrium model instead of partial balances, and the financial sector be considered in the social accounting matrix (FSAM) so that a higher degree of trust can be achieved.

Unemployment duration is the length of time that an unemployed person looks for a job. It is an indicator of labor market performance. In other words, a longer period of unemployment duration reflects the poor performance of labor market and implies that structural barriers prevent the employment of unemployed. In recent years, the unemployment rate in Yazd has exceeded the average unemployment rate in the country, and this has made unemployment an important issue in Yazd. In this regard, unemployment duration is of importance. Accordingly, identifying the factors affecting the unemployment duration is as important as identifying the factors affecting the unemployment rate. Unemployment insurance is a factor affecting the unemployment duration. On this basis, the purpose of this study is to investigate the effect of unemployment insurance on unemployment duration in Yazd.

In the present study, the generalized Cox proportional hazard model has been used as a statistical method to correlate survival with a number of explanatory variables. This model belongs to the group of non-parametric models and is a function of time and explanatory variables. One of the features of this model is the proportional hazard assumption, according to which the risk ratio is always a fixed number and independent of time. If the explanatory variables in the exponential expression are not time-independent, the generalized Cox proportional hazard model is applicable. The exponential part of the generalized Cox proportional hazard model includes time-independent and time-dependent variables. In the present study, the maximum likelihood method has been used to estimate the parameters, in which the parameters are obtained by maximizing the probability function. In the model of this study, the unemployment duration is a function of unemployment insurance and a vector of explanatory variables including age, gender, marital status, employment history and number of children. Unemployment duration in terms of day and unemployment insurance, which is the wage given during the unemployment or a coefficient of wage that is received based on the minimum wage, is entered into the model. The statistical population of this study consisted of the unemployed job seekers who were unemployed from 2013 to 2017. They received unemployment insurance and were re-employed. Raw data were collected from the Department of Labor, Cooperation and Social Welfare Organization and the Social Security Organization of Yazd.

The distribution of statistical population according to the unemployment duration shows that the unemployment duration of 66.2% was under 12 months and of 29.8% was between 12 and 24 months, which accounts for 96% of the statistical population. Also, the unemployment wage (unemployment insurance) of 74.1% was equal to the minimum wage and of 25.9% was more than the minimum wage. In addition, unemployment wage (unemployment insurance) has a positive and significant correlation with unemployment period. The results of estimating the generalized Cox model show that unemployment insurance has significantly increased the unemployment duration, and the increased unemployment insurance has resulted in increased unemployment duration. Also, being single and having no children leads to an increase in the unemployment duration. In contrast, employment history and age lead to a decrease in the unemployment duration. In other words, people who received unemployment insurance, namely those who were single and had no children, left the unemployment duration later, and people with a longer employment history and age left the unemployment duration earlier. In addition, gender did not have a significant effect on the unemployment duration. According to the coefficients, unemployment duration is more affected by individual characteristics than by unemployment insurance. Also, among the variables, the largest coefficient is related to being married.

In this study, for the first time, unemployment insurance is included in the model not as a dummy variable (receiving or not receiving unemployment insurance) but as unemployment wage. This is used as a coefficient, or the ratio of unemployment insurance to minimum wage. The results of the model estimation showed that unemployment insurance significantly increases the unemployment duration. Most studies confirm this result. However, a few studies such as Carling et al. (1996) in Sweden, Tatsiramos (2006) for European countries, Fitzenberger and Wilke (2007) in Germany and Galean et al. (2019) in Spain contradict the results of the present study. This study showed that the benefits under unemployment insurance payment are as important as the payment period to reduce the length of the unemployment duration. Also, policymakers should reduce the adverse impact of unemployment insurance on the unemployment duration by paying attention to both benefits and duration. Therefore, if unemployment insurance benefits gradually decrease over time with increasing unemployment duration, the incentive to re-employ will increase. In addition, paying attention to the education and training of the unemployed by emphasizing on technical and vocational training can provide the basis for reducing the unemployment duration.

It is important to note that the effects of different methods of government financing (such as taxes, borrowing, selling natural resources, etc.) are not the same in the economy, and these different methods can affect macroeconomic variables such as economic growth in different ways. Therefore, answering the question of what is the optimal government-financing portfolio in the economy is of particular importance, especially in developing countries where the sale of natural resources plays an important role in their financing portfolio. According to Sachs and Warner, the abundance of natural resource encourages rent seeking, corruption, and poor government management. It also encourages developing countries to engage in protectionist paths through state-led projects of development, in fear of “Dutch disease effects of the resource abundance”. Yet, as de Ferranti et al. (2002) put it, ‘it is impossible to argue that Australia, Canada, Finland, Sweden and the United States did not base their development on their natural resources.’ (p. 6)Accordingly, considering the three main current issues of Iran's economy based on a) inefficiency of the tax system, b) dependence of the budget on oil, and c) growing government debts, this paper investigates the effect of government financing methods on the economic growth in Iran from 1973 to 2018 using a Markov-Switching (MS) model. Following the generalized growth accounting model based on neoclassical and endogenous growth models, to investigate the effect of different methods of government financing on the economic growth, we used the following model based on the concept of the total production function:    where:GY: GDP growth rate (constant 2011 LCU),GK: Gross capital formation growth rate (constant 2011 LCU) as a proxy for investment growth rate,GL: Population growth rate as a proxy for labor growth rate,GX: Export growth rate (constant 2011 LCU) as a proxy for export growth rate,TR / Y: Government tax revenue as a percentage of GDP,OR / Y: Government oil revenue as a percentage of GDP,GD / Y: Government debt as a percentage of GDP.In addition, this study uses annual time series for Iran during 1973-2018. Based on the specification tests, we estimated MSI (2) model using the EM algorithm as reported in Table 1. This model was tested for linearity using the LR linearity statistics assuming the null and alternative hypotheses to be a linear model and an MS model, respectively. The probability value of the Chi^2 statistic in this test (0.005) supports the existence of non-linearity in the data. Based on the transition probabilities, the probability of moving from regime zero (one) to one (zero) regime is 0.6879 (0.6374). Therefore, it can be said that the probability of staying in both regimes is moderate. Table 1. Results from MSI (2) Coefficient t-value t-probSwitching variables in Regime 0Intercept0.600.2940.771GY (-1)-0.04-0.810.423TRY0.110.380.704ORY-0.18-3.250.003GDY-0.44-5.280.000GDY (-1)0.263.190.004Switching variables in Regime 1Intercept1.470.690.496GY (-1)-0.30-5.020.000TRY0.86 2.540.017ORY-0.10-1.840.076GDY-0.70-8.800.000GDY (-1) 0.51 7.550.000Non- switching variablesGK0.137.310.000GL4.094.860.000GL (-1)-1.24-1.300.204GX0.2416.10.000AIC = 5.33                   SC = 6.09Linearity LR-test Chi^2(9) =   42.361 [0.000]p_ {0|0} = 0.6879;                       p_ {1|1} = 0.6374p_ {0|1} = 0.3121;                       p_ {1|0} = 0.3626     Normality Test: Chi^2(2) = 0.08 [0.959] ARCH 1-1 Test: F (1,26) = 1.13 [0.298] Portmanteau (6): Chi^2(6) = 10.46 [0.106] Note: In this study, in order to determine the optimal lag of variables, the autoregressive distributed lag (ARDL) technique was used. Also, the unit root tests results showed that all the variables were stationary.* Annual data for all the variables were obtained from the Central Bank of Iran.Source: Research findings  Figure 1. Regime classification based on the filtered and smoothed probabilitiesSource: Research findings In addition, the cumulative effects of explanatory variables are presented in Table 2: Table 2. Cumulative effects of explanatory variables on economic growth in zero and one regimescoefficient in regime onecoefficient in regime zerovariable0.1250.1GK2.742.19GL0.230.18GX0.110.66TR/Y-0.17-0.08OR/Y-0.17-0.14GD/YSource: Research findings                                        This paper investigates the effect of government financing methods on the economic growth in Iran from 1973 to 2018. To this end, a Markov-Switching (MS) model was used. The results showed that the tax-to-GDP ratio had a positive effect on the economic growth in both recession and boom regimes, although this effect was not significant in the recession regime. Given the low tax-to-GDP ratio in Iran, these results have not been unexpected. Also, based on the findings of this study, the ratio of government oil revenues to GDP had a negative and significant effect on economic growth in both identified regimes, which confirms the theory of resource curse phenomena or paradox of plenty in the Iranian economy. In addition, the findings of this study showed that the ratio of government debts to GDP had a negative and significant effect on the economic growth in both regimes. The reason for this negative impact could be the fact that government borrowing in Iran is used to compensate for structural budget deficits instead of spending on productive investments and building the necessary infrastructure. Finally, the findings showed that the investment growth rate, population growth rate and export growth rate had positive, significant and tangible effects on Iran's economic growth, respectively.

One of the words that is heard in the present life is digital currency Digital currency is a component of a decentralized financial system to facilitate economic transactions through evicting intermediaries such as banks as much as possible. In the meantime cryptocurrency is a digital or virtual currency that is secured by cryptography and made nearly impossible to counterfeit or double-spend. In the early 1990s, some elite people intended to give more freedom to the people through the use of the Internet and reduce the power of governments. The main goal of these elites was to empower people to control money and information and to simply eliminate intermediaries such as banks. Templates based on time series equations are a new type of economic modelling that dates back to the early 1970s. Time series patterns include a wide range of economic patterns, the most important of which is the vector auto regression pattern. Time series equations can be extracted in two ways, including a method of inference from theory and then modelling according to the researcher and the relevant statistical tests to determine the accuracy of the model and the estimated parameters. This type of modelling faces several problems such as unstructured parameters, structural shock detection, and specification error. Due to the nature of partial equilibrium, they sometimes have difficulty understanding the economic conditions and erroneous predictions. The problems are due to the difference between the model and the economic theory. To solve these problems, dynamic stochastic general equilibrium (abbreviated as DSGE, or DGE, or sometimes SDGE) models were used. This kind of modelling is a macroeconomic method often employed by monetary and fiscal authorities for policy analysis, explaining historical time-series data as well as future forecasting purposes. The present study has used the DSGE method to estimate the model. In this model, it is assumed that households gain utility from consumption, government currency and cryptocurrency, and labor supply has inutility for those households. Therefore, they try to maximize its utility by using their budget constraint. Another part of this study is the entrepreneurial section (cryptocurrency miners), which assumes that there is a continuous chain of entrepreneurs denoted by n, and that each entrepreneur operates under conditions of perfect competition. The third part is the manufacturing firm, which assumes that firms are different in an exclusive competitive environment for the production of intermediate goods and have access to other intermediate goods of other firms to produce a final product under perfectly competitive market conditions. The last section is the central bank, which determines the monetary policies governing the society. In this study, it is assumed that the central bank uses the nominal interest rate as a rule set in a modified Taylor (1993) model. This model is estimated using the monthly data of Iran, and the results show that there is a strong substitution effect between the government currency real balance and the cryptocurrency real balance in response to technology, preferences and monetary policy shocks. In addition, government currency demand shocks have a greater impact on the economy than the cryptocurrency demand. Cryptocurrency productivity shocks also lead to a decline in the nominal exchange rate. Production and inflation decrease when nominal interest rates increase. However, the effects of these shocks are much less than those of traditional shocks. Overall, this study provides new insights and evidence on the underlying mechanisms of cryptocurrency and its effects on the economy. It can be a guide for investors, policymakers, central bankers and researchers as how to operate cryptocurrencies and the corresponding ecosystem in the future. In particular, two policy recommendations emerge from the analysis of this study. First, according to the results, it was shown that increasing the supply of cryptocurrencies has a negative effect on production. Thus, monetary authorities may decide to adjust the rates in response to the changes in the cryptocurrency real balance, which include the weight for cryptocurrency growth, as a policy response. Second, if the central bank is to prevent a decline in output, the nominal interest rate response to the changes in government currency growth must be gradual. Furthermore, there is a strong alternating effect between the real money balance and the real money code balance in response to technology, preferences and monetary policy shocks. As the important finding of the study, the increase in production and inflation is greater when cryptocurrency is not present in exchanges, indicating that more inflation exists when there is no cryptocurrency.

The economy of a country undergoes many fluctuations over time. Due to dependence on oil revenues, war, embargo and other economic and political tensions, Iran's economy has been fluctuating greatly and experiencing many periods of prosperity and recession in the last thirty years. One of the duties defined for governments in public finance is economic stabilization. Economic stabilization makes the path of economic growth smoother. The smoothing of the growth path also makes the economic environment more attractive for investment and production. Governments have different instrument for economic stabilization. These instruments affect the supply and demand system. One of the policies that affects the demand side of the economy is the financial policies. These policies are divided into two categories: discretionary and non-discretionary. Discretionary financial policies were criticized by economists such as Friedman. Critics state that discretionary policies do not have the appropriate speed to stabilize the economic fluctuations. Automatic stabilizers, however, are not discretionary policies and can respond appropriately to criticism. The purpose of this research is to investigate the effect of the automatic stabilization of financial policies, especially tax policies, on Iran's business cycles.

The data collection of this research was done through library work. The data were collected from the Central Bank of the Islamic Republic of Iran and the National Statistics Center. The data were seasonal, ranging from the spring of 1993 to the autumn of 2018. The business cycle of Iran's economy was extracted using the Hodrick-Prescott filter. According to the studies conducted, the ʎ of the extraction filter was 677. The unit root was calculated using the KPSS test. All the variables at this level were stationary. By estimating a SVAR model, we tried to check the dynamic relationships among the variables. The tools that were used in structural vector autoregressive models were impulse response functions, forecast error variance decomposition and historical decomposition. The counterfactual analysis was based on historical decomposition.

The SVAR model was formulated with the impulse response functions for twenty periods. According to the results, the effect of the government expenditure shock on the business cycle is low, but it shows up positive. The effect of the indirect tax shock on the cycle of GDP is very small and negligible. The effect of the direct tax shock on the business cycle is estimated counter-cyclically and found to be of a low effect.The results of the variance decomposition show that, in the first period, more than 92% of the change in the business cycle is explained by itself, 5% by the government expenditure shock, 1% by the direct taxes shock, and very small amounts by the indirect taxes shock. After 20 periods, the contribution of the business cycle in explaining its own changes decreases by less than 5%. Most of this share is added to the share of the government expenditure shock, raising it to 9.27% to explain the changes in the business cycle. After twenty periods, direct and indirect taxes are only equal to 2 and 1%, respectively, and they serve as the cause of changes in the production cycle.Historical decomposition shows that in the period from 1993 to 2018, direct taxes had a small contribution to the business cycles of Iran's economy, but there were countercyclical effects on the business cycle different years. These effects can be seen during both boom and recession. Indirect taxes have had counter-cyclical effects only in a few years, which have only been anti-prosperity. Historical decomposition shows that government spending has been able to exert anti-cyclical effects in some cases, though negligible.

According to empirical studies and the financial structure of the Iranian government, it was expected that the effects of stabilizing taxes on the production cycle would be insignificant. The tax ratio on GDP in Iran is about one third of the usual rate in the world. What matters was the way these taxes were effective; they affect the GDP in a pro-cyclical or counter-cyclical way. In this research, an attempt was made to investigate the role of taxes and the automatic stabilization of the government's financial policies in the economy of Iran. The results showed that, in terms of quantity, the government spending has a greater effect on stabilizing the economy (although this effect is small). However, in terms of counter recession effects, direct taxes can have a good stabilizing effect on the production cycle in the economy, although it is natural that the contribution of few tax revenues from the government's revenues in terms of quantity does not have a significant effect on the current economy of Iran. By increasing the share of tax revenues from the total revenues of the government, it is hoped that the counter recessionary effects of direct taxes will help stabilize (automatically) Iran's economy and reduce some of the economic fluctuations of the country's production. It is suggested that the government's financial policy should be made with special attention to direct taxes. By increasing the share of direct taxes, there will be fairer taxation as well as a relative improvement in fluctuations at the country's macroeconomic level.

In most countries, government expenditures are provided from tax revenues. But, in Iran, government budget depends on oil revenues. In other words, various economic activities in Iran such as bank deposits interest and stock earnings are tax-exempt. Although tax exemption pursues some goals, it reduces government revenues. In recent years, after severe sanctions against Iran's oil exports and a sharp drop in government oil revenues, increasing tax revenues has become one of the main alternatives to offset the decline in the oil revenues. On the other hand, the increased participation of investors in the stock market in recent years has provided a good opportunity for the government to increase its revenues in order to reduce budget deficits. Dividends and interests on bank deposits can be considered as new tax bases. It is reported that the Iranian National Tax Administration and the Ministry of Economic Affairs and Finance intend to levy taxes on bank deposits interests and dividends, but this plan has not yet been implemented. Therefore, it is necessary to study this issue. In this regard, the purpose of this study is to investigate the effects of taxlng stock earnings and bank deposit interests on macroeconomic variables with a dynamic stochastic equilibrium (DSGE) approach. This research investigated the effects of stock earnings and bank deposits tax shocks in the context of Keynesian dynamic stochastic general equilibrium (DSGE) approach during the years 1991-2019. The economic model in this study includes households, manufacturing enterprises, banks, government as fiscal policymakers and the central bank as monetary policymakers. Intermediary firms operate in a monopoly competition framework, and the Kalvo pricing method is used to express price rigidity. The purpose of using this method is to avoid model's rapid adjustment in response to shocks. The problem with analyzing stochastic dynamic general equilibrium models is that equilibrium equations are nonlinear, so linearization is necessary. For linearization, Taylor’s expansion method is applied. The linearized logarithm equations of household demand for stocks show that the amount of investment in the financial market depends on income, future price expectations and the expected dividends. To solve stochastic general equilibrium models, the parameters of the calibration model must be quantified. The conventional method to quantify the parameters is the calibration method. It is believed that the corresponding tax policy has not yet been implemented in Iran. Also, because of poor statistical data, this study uses the calibration method instead of Bayesian method. In this method, the parameters of the model are selected in such a way that the best match is achieved between the predicted moments of the model and the real data moments of the Iranian economy. The results show that taxation on bank deposit interests reduces the amount of bank reserves. Then, as a result, banks request higher rate for lending, and the amount of loan demand is reduced. Ultimately, the influx of cash into the production sector and investment decreases. The results of this model are consistent with Gondolfi's theory (1982) that states savings decrease due to increased interests on bank deposits. Note that the government tax revenues increase with the imposition of a tax on bank deposits, but it soon deviates from its stable amount and then begins to decrease. This is due to the transfer of resources to other financial markets which are tax-exempt. Furthermore, with the introduction of stock income tax, the demand for stock will decrease, so does the amount of productive investment. This makes companies face financing difficulties. With reduced level of total production, the disposable income of shareholders and consumption will be reduced. Although, government tax revenues increase after the implementation of the stock tax, after a few periods, the dividends and stock prices as well as the amount of government revenues from the stock income decrease, and the tax revenues move towards a stable amount. According to the results of this research, it can be concluded that, if the purpose of deposit taxation is to expand the government taxes, instability should be prevented in parallel markets by implementing pre-determined policies. One of these policies is to expand the tax base by imposing a tax on other financial markets such as the foreign exchange, gold, and housing markets. On the other hand, taxation on stock markets increases the amount of liquidity in the economy and transfers path of liquidity. If liquidity is directed to the deposit (in the absence deposit tax), the process of moving to a stable position will proceed more rapidly. This is because companies are financed with bank loans and financing problems are partially solved. If liquidity is diverted to speculative activities, however, it will have detrimental effects on the economy.

Economic sanctions are one of the tools to exert negative pressure on a country's economy to achieve political goals. They have been used in several cases in recent years due to their lower cost than war for the country that imposes them. What matters is the cost of economic sanctions for the imposing country and what it gains from it. The gain of sanctions for this country is the effects on the economy of the target country. Experimental observations show that, despite the same political disputes of different countries with one country (USA), the severity of sanctions imposed on these countries is different. Even despite the same sanctions imposed on the target countries, the economic responses of these countries to sanctions are different. Many studies have been conducted on economic sanctions and their impacts on the economic and welfare situation of the target countries. Not all of them have reacted the same way. In this article, we have discussed the differences in the impacts of economic sanctions on different countries, focusing on the situation of Iran and Russia. Due to the differences between the sanctions severity imposed on the two countries, the sanctions variable was initially quantified to provide an equal basis for our analysis. We entered resilience and vulnerability indices into our model to explain the different effects of the sanctions on the two countries. We also modeled the sanctions severity to consider the its differences in the case of different targets.

By comparing the effects of sanctions on the export and import of the target country to and from important trading partners, we estimated those effects using panel data with interactive dummy variables. The model proposed by Raul Caruso in 2005 was used to examine the impact of sanctions on the trade of the target countries. The trade data of Iran and Russia with five important partners between 1992 and 2018 were used in the model. We also used the US Congress report on the sanctions against Iran and Russia to quantify their sanctions. In the discussion of scoring sanctions, number zero is related to the period when no sanctions were imposed, numbers 1 and 2 are related to the mild and severe sanctions of the United States, numbers 3 and 4 are related to the mild and severe sanctions of Europe, and number 5 is intended for the sanctions imposed by the United Nations. Finally, by determining the severity of sanctions in different sectors of Iran's trade (different partners), we sought to show the effects using vulnerability and resilience as two indicators.

he results showed that economic sanctions have had significant and negative effects on Iran's trade with its important partners, but they have had no significant effect on Russia's trade with its partners. Since economic sanctions enter the economic systems as a negative shock, the difference in their impacts is considered to be related to the indicators of vulnerability and resilience. It was observed that resilience has reverse and vulnerability has direct effects on sanctions. This important finding shows that, by modifying resilience and vulnerability, we can affect the impacts of sanctions. Increasing resilience and reducing vulnerability can reduce the impact of economic sanctions on Iran. On the other hand, since Russia's economy is more resilient and less vulnerable than Iran, the difference between the impacts of economic sanctions on these two countries is explicable.

In this study, we tried to examine the reason for the differences in the impact of economic sanctions on different target countries. We focused on Iran and Russia because of the similarities in the nature of the exports and political disputes with Western countries. For the severity of sanctions imposed on the target countries, we used six levels (0-5). We also considered the trade of Iran with five important partners (i.e., Germany, China, India, Turkey and UAE) and Russia Trade with its partners (Netherland, China, Belarus, Germany and Turkey) as an index for measuring the sanctions impacts. It emerged that the sanctions have had significant negative effects on Iran's trade with its important trading partners, but thet have had no significant effects on Russia's trade. We entered resilience and vulnerability indices into our model to explain the difference of the effects on the trades of Iran and Russia. It was observed that the impact of sanctions is inversely related to resilience and directly related to vulnerability of an economy, meaning that the higher the resilience and the less vulnerable a country is, the less affected by sanctions.

Exchange rate is a measure of the equality of a country's currency against the currencies of other countries. It indicates the measurement of that country's economic situation in comparison with other countries. In the framework of conventional economic theory, the exchange rate system refers to the mechanism of determining the exchange rate through market forces exerted on the supply and demand.The purpose of this study is to understand the dynamics governing the exchange rate behavior using nonlinear models. By understanding the exchange rate dynamics, one can recognize its unusual and worrying behavior over time and apply the necessary policies accordingly.

The baseline linear model used in this study is a finite-order autoregressive (AR) model with relation (1):(1) In the real logarithm of the real exchange rate, the interrupted polynomials are placed in the roots of ϕ (z) = 0 on or outside a single circle. The roots outside the unit circle mean that PPP remains stable in the long run.Regime change regressionTwo-mode TAR (2) models are defined as follows:(2)  In the above relation, there is a sequence of white noises with mean zero and variance 1. In this model, it is assumed that the variance in each regime is different from that in the other regimes. In order to complete the above definition, the R1 and R2 regimes need to be described more precisely. It depends on how each regime changes over time.Introducing the Bayesian modelIn order to estimate the Bayesian SETAR, we assume that the exchange rate variable has a normal distribution.(3)  In the SETAR model, the regime change is defined as a discrete variable as follows:In the next step, in order to have a Bayesian estimate, we need to specify the backgrounds of the model coefficients and the other parameters. An appropriate assumption in this regard is to assume that the anterior distribution r is a continuous uniform distribution whose boundaries include the minimum and maximum time series data as follows:In the next step, we will define the backgrounds for the coefficients. According to the objectives of this study, we will use the background for the ignorance of the normal part as follows:Bayesian estimation methodThe basis of Bayesian inferences is Bayesian theorem. According to this theorem, the posterior probability of an event varies according to the product of the previous probability in the logarithm of the orthogonality. In mathematical terms, Bayes' theorem is as follows:

Table 1 reports the results of the SETAR model estimation for the exchange rate return (Rials against the dollar with the monthly rotation in the period from 2004 to December 2020). The validity intervals of the coefficients are adjusted and do not include zero, which, like the classical case, is based on the significance of these  coefficients. Table 1. Bayesian SETAR model coefficients (1) for the dollar exchange rateCoefficients Posterior average Posterior  standard deviation95% confidence interval 0,00790,0023(0,0034;0,0123) 0,31790,0713 (0,1773;0,4567) 0,01470,0161(-0,0172;0,0465)  0,43380,1468(0,1427;0,7244) 0,02230.0006 (0,0208;0,0230) Table 2. Variances of the two regimes in the Bayesian  SETAR (1) model for the dollar exchange rate Coefficients Posterior  average Posterior standard deviation95% confidence interval 0/00070/0001(0,0006;0,0009) 0/00940/0019 (0,0064;0,0137)  According to the results of Table (2), when the exchange  rate is lower than the latter value of thresholds, its variability is much less than when the  exchange rate is higher than the threshold value (variance in regime 2 is greater than that in regime 1)Figure (1) shows the autocorrelation of the simulated values in the latter estimation of the model parameters in the two regimes. Figure 1. Autocorrelation of the posterior coefficients in both regimes 1 and The results in Figure 1 show that the correlation of the simulated values for all the model parameters rapidly decreases to zero. Therefore, we are faced with a suitable sample of values to simulate the posterior distribution of the parameters. There is also no need to increase the simulation volume.Figure (2) shows the effect curves of all the later parameters of the model used in this research: Figure 2. Effect diagrams for the SETAR pattern parameters (1) Based on the findings about the curve of the effect related to all the parameters, no regular pattern exists in the simulated values ​​of the parameters. Therefore, the stability of these coefficients is confirmed, and the results of the Bayesian model SETAR (1) used in this study are statistically valid. 

The exchange rate as a price variable plays a very important role in the performance of an economy. The results of this study indicate that there are two exchange regimes in which the exchange rate adjustment parameter will be in equilibrium with a 95% probability in regime 1 (0.1773,0.4567). This is very small due to the deviation of the latter standard of this coefficient (S. Dev = 0.0713). Also, the same parameter with a 95% probability in regime 2 will be at the distance (0.1427, 0.7244), which is a relatively long distance. The results showed that this is due to the high volatility of the exchange rate in regime 2. In addition, the adjustment in the first regime to the long-term equilibrium path is much safer than the adjustment to the long-term path in the second regime because the variability in the conditions of the exchange rate increase is very high. Finally, the results of this study showed that the expansionary exchange rate regime (regime 1) has a deviation from higher regime standards than the mild exchange rate regime (regime 2), which indicates high currency fluctuations in this regime and more uncertainty. So, using regime 1 provides the conditions for a proper economic growth in the future.

Income distribution is one of the economic variables in the field of macroeconomics whose improvement is always a concern of governments. Income distribution shows the share of each member of the society in national income. The most important results of an increase in income inequality are increased rents and corruption, reduced entrepreneurial rate in the society and increased size of government. Also, the existence of a large traditional sector with low potential for modernization and a low and volatile level of economic growth rate is another characteristics of economies with high inequality in income distribution. All economies are somehow faced with macroeconomic shocks, but the dependence of oil-exporting countries on foreign exchange earnings from oil sales has made changes in oil revenues, which is a major cause of economic fluctuations in these countries. In Iran, exports and government budgets depend heavily on oil revenues, so that any move to the global oil market severely affects the government budgets and the structure of the economy. Thus, the prominent role of oil revenues in the structure of the government budgets and the social security programs has distinguished the Iranian economy from other economies. Studies show that countries with a high share of natural resource exports experience two to three times more fluctuations in their foreign trade than other countries. Oil wealth harms the poor by creating economic fluctuations in the countries that export this product through two channels that include creating economic shocks and destabilizing government revenues, and increasing income inequality. Therefore, considering the importance of the subject, the main purpose of this study is to investigate the impacts of shocks and uncertainty of oil revenues and sanctions on the income distribution in the Iranian economy.
In this study, in order to investigate the impacts of oil market shocks (good and bad news) and sanctions as well as the effects of uncertainty in the income distribution inequality, the index of VARMAX GARCH-in-Mean Asymmetric BEKK model has been used for the period of 1991: 1 to 2019: 1.
The results showed that positive shocks to the oil revenues led to improved revenue distribution in the short term. One of the strengths of the present study is to consider the effects of the structural failure of the variance of variables in the studied model, which has led to an increase in the accuracy of estimating the model coefficients. The significance of the structural failure coefficients (across the origin) in the equations of variance indicates that, in terms of structural failure (variance) in the model, the amount of turbulence in all the variables increased, so in the period when production variance had structural failure compared to the period when there was no structural failure, there was less relative stability in the economic growth. In addition, the results of estimating the research model confirm the existence of asymmetric effects of shocks (good and bad news) on the turbulence of all the variables, so that the intensity of these asymmetric effects in the turbulence of oil revenues, economic growth and inflation was relatively higher. These variables are highly sensitive to the arrival of bad news, and this type of news is an important factor for the instability of the variables studied in this period. According to the estimation of the GARCH sector coefficients, the turbulence of all the variables is transmitted to the turbulence of the income distribution inequality index, and the instability in each of these sectors leads to its transfer to the income distribution index. Also, the significance of the estimated coefficients in the GARCH sector confirmed the transfer of the sanctions turbulent overflow to all the sectors, including income distribution, which confirms the effective role of sanctions in creating instability in Iran's macroeconomy. Therefore, if the sanctions continue, the establishment of relative stability will face a serious challenge.
Despite the view of many economic thinkers that one of the main causes of poverty and income inequality is lack of capital, and money accumulation, the experience of many oil-exporting countries, including Iran, with regard to oil revenues shows the opposite. Many studies have shown that, despite the abundance of oil resources and high government revenues from oil revenues in countries with oil reserves, including Iran, income inequality is exacerbated. This is due to their lack of attention to tax revenues, over-dependence on oil revenues, lack of strong links between oil-related industries and other economic sectors, the lack of proper influence of this sector on employment, and the orientation of public spending towards the wealthy classes,. In contrast, studies in developed countries indicate that reducing inequality and improving income distribution by increasing transfer costs and targeted subsidies from sources of increased energy revenue have led to improved health and education indicators.

One of the most important goals of the third millennium is to promote gender equality. This means that women should have equal opportunities to develop their talents. But the statistical evidence clearly shows continuous significant differences at the level of education, health and, most importantly, income between developing and developing countries. Economists have proposed different theories and models to explain the reasons for the gap between developing and developed countries. These theories attribute the gaps to institutional factors such as education and health. Therefore, given that gender poverty is inherent, understanding the corresponding interactions is essential to designing and implementing policies that help reduce the gender gap and free women from poverty. New institutionalists believe that an institutional change affect their choices and, consequently, the economic performance of the society in the long run by changing the motivational structure of individuals. Among various institutional factors, democracy along with factors such as physical capital and human capital seem to play prominent roles in the process of development and poverty reduction of countries. Explaining the concept of democracy, Jeremy Bentham states that each member of the society should be considered as one person. In fact, the basic premise of democracy is the participation of citizens in decision-making and the equality of all the members of the society, far from gender gaps. Accordingly, it seems that the democratic or authoritarian nature of the ruling structure can be a significant factor in determining the status of development and poverty. Many political scolars have tried to prove the hypothesis that development increases the demand for maximizing political rights. Indeed, the traditional argument that development paves the way for democracy was first put forward by Seymour Martin Lip set et al (1959) and then by Rueschmeyer et al. (1992), Daya Mond (1992), Lip set et al. (1993). According to this argument, high welfare promotes democratic institutions and moderates social contradictions by creating a broad middle class and eliminating social gaps. According to this view, the realization of democracy is related to the level of economic development, and a country is likely to achieve democracy when it has undergone stages of economic development or its citizens have received a certain level of education. It is also claimed that the factors that contributed to the rise of democratic regimes in the 1970s and 1980s, most of which were authoritarian, were the high levels of economic recovery that led to the expansion of literacy, education, and urbanization to the middle class. It strengthened pro-democracy values ​​and behaviors. Democracy is based on the luxury of goods and can only be used after the difficult task of development has been completed. In the opposite view that democracy is the agent of development, a group of thinkers such as Amartya Sen emphasize that freedom and democracy are parts of development. It has been  also pointed out that sustainable economic growth occurs only in democracies,  and that democracy is a factor in the elimination of gender gaps and the better functioning of the economy. In the present study, a comparative analysis is performed of poverty reduction through education, income and health gap indicators with an emphasis on democracy. It is done by examining the two perspectives raised during the period 20-20-2004 and using the panel soft transfer threshold (PSTR) approach. The questions to answer are ‘Can differences between men and women in terms of wages, education, and life expectancy considering the system of democracy and autocracy in countries with a very high human development index have an impact on poverty reduction?’ and ‘In which category of countries is this effect greater?’ According to the obtained results, the variables of educational gap, income and health have positive relationships with the poverty gap index in both groups of the studied countries. The coefficients of variables in countries with very high human development index are close to zero. According to the ranking of this group of countries in terms of human development, the values of these coefficients are justified. Also, the coefficients of variables of the type of government system in both groups of countries have no effect on the difference between the study groups. The main factor in reducing poverty is reaching the desired level of development, which means rejecting the view that democracy is the factor of development. In addition to the fact that the traditional structure in developing societies can always create many obstacles such as traditionalism, conservatism and self-righteousness, in the path of political development, the accelerated movement of modernization has also created gaps in the society such as generation gap and identity crisis. Therefore, in general, the main factor in reducing the poverty gap in a country is the improvement of economic and development indicators, including gender, education, income and health gaps; once the gap indicators are improved, democracy will follow.

Reducing dependence on oil revenues and financing government expenditures from tax revenues have always been emphasized in the country's development plans. Increasing the role of taxes in financing the government budget, as a stable source, is one of the government's concerns. This has been evident in the development plans, especially since the Third Economic Development Plan. The dependence of the budgets of oil-exporting countries on revenues from the oil export can have devastating effects on the economies of these countries such that a significant part of government revenues is subject to high fluctuations which are later transferred to government spending as a tool of fiscal policy. Fiscal instability of the government causes instability in essential public sector expenditures, which undermines the long-run growth. The existence of financial stability is a key to achieving macroeconomic stability/ It enables the continuation of expenditures related to public goods needed to lay the grounds for economic activities that ensure long-run economic growth. However, tax income is the most appropriate type of government revenue, and the higher the share of taxes in government spending, the less economic impact it will have. Compensation for the reduction of tax revenues due to exemptions causes the government budget to become more dependent on oil export revenues, which can have harmful effects for the country. The corrective approaches in tax laws with the aim of increasing tax revenues can be the introduction of a new tax base with two methods reducing tax rates and increasing the base. One of the tax exemptions granted in the Iranian tax system relates to the income from the interests on saving accounts and bank deposits. In this study, the impact of bank interest taxes on economic variables is investigated. So far, several domestic studies have been conducted in this field.  The model used in this research follows Boscá et al. (2019) and Gerali et al. (2010), but it is adapted to the conditions of the Iranian economy.

The impact of tax on bank interests on economic variables in Iran can have many positive and negative economic effects. Therefore, in this study, the impact of tax on income interest on macroeconomic variables is investigated. Given that this tax is imposed for the first time on the Iranian economy with no historical data, its effects can be examined in the framework of a dynamic stochastic equilibrium model. The innovation of this research is to generalize the analytical framework of dynamic stochastic general equilibrium models according to the economic characteristics of an oil-exporting country, including households, firms, banks, government and central bank. For this purpose, the model has been designed in accordance with the conditions of Iran's economy. The objective functions and constraints of each of these economic agents are introduced, optimized and used from the first-order conditions, a set of economic relations is extracted, and then the model is simulated by determining its initial values ​​ and calibrating the parameters. To evaluate the model, the moments of a number of endogenous variables of the model are compared with the real-world moments, which results in relative success in simulating the variables in the Iranian economy. Finally, the reactions of the variables to the tax on interests are examined.

The results show that, by taxing on the interest income of households, household’s consumption, national employment and production increases. On the other hand, the power of the bank’s loan payment decreases and, consequently, the borrowing by the banks from the central bank increases (in order to compensate for the lost resources). Also, by imposing a tax on interests, the demand for facilities and, consequently, the total payment facilities of commercial banks and the Ricardian household’s deposits in the bank are reduced, which leads to the reduction of the total power of banks to give loans. In addition, with the increase of facilities to firms and the reduction in the payment of loans to the Ricardian household, the composition of commercial bank assets will change.

In countries with economic instability, the imposition of a tax on interests can lead to the withdrawal of financial resources from banks and their investment in non-productive economic activities, thus causing more instability in the economy. The first recommendation in this regard is that, before imposing such a tax, it is necessary to stabilize the economy. In addition, to measuring the effects of the tax on the interests of bank deposits on economic variables, the efficiency of the budget and the efficiency of the banks to direct the deposits to production and investment become particularly important. The results suggest that the allocation of resources by the banks should be more efficient, because the reduction in the amount of deposits may result in inefficient allocation of resources.