Iran’ s economy has been always under pressure to provide resources for public spending and it is limited by a tax system that causes disruption in the behavior of economic agents; therefore, it is expected that the country’ s tax system can be improved via inspiring by the global tax reforms. The opponents argue that the lack of comprehensive tax information system, low administrative capacity of the tax Agency and taxpayers, and different economic structure of Iran make such reforms impossible in Iran. But it must be emphasized that Iran’ s economy will face three major challenges in the field of social security, reduced tax revenues from international trade and competitiveness in the near future. Therefore, expanding the tax bases and lowering the tax rates is necessary in dealing with these challenges, and this is possible through the comprehensive income tax system. The main objective of this study is to investigate and compare the comprehensive income tax system and its adjusted versions with the tax system in Iran. The results show that the Iran’ s tax system is very complex and violates the principles and objectives of tax reform in many cases. Furthermore, high tax burden on companies, high rates of social security, and widespread tax evasion in the self-employed section are among the features of the Iranian tax system which apart it from other common tax systems in the world. In order to reform the tax system in Iran, the best method is fundamental reforms based on the comprehensive income tax system, if it is not possible for any reason (the lack of prerequisites or political consensus), we can do some adjustments (reform in a scientific framework based on tax expenditures and economic interests; simplifying the tax system; bias correction in providing corporate finance method and mitigating double taxation; threshold for exemption based on relative poverty; adjustment of tax threshold, depreciation, and interest deductions for inflation; change of executive system from tax-based structure to functional basis structure; improvement of tax justice perception; change the tax unit from the individual to the family; providing tax system without having to provide tax returns from taxpayers) to improve the existing system.

Iran’s tax system indicators, such as lower ratio of taxes to GDP and funding resources, tax pressure on companies in direct tax bases and focus on import tariffs in indirect tax bases, indicate that the structure of tax system in Iran is not desirable. Comparison between corporate tax and income tax that the latter includes all income in economy, indicates an imbalance, injustice and inefficiency in collecting taxes on income, and shows that economic agents, despite companies, do not pay taxes proportional to their income. In the case of indirect tax, there is not a general consumption or sale taxes, and what exist under this title, just include excise taxes and very limited kind of VAT.To improve Iran's tax system, in this paper, we provide structural reforms as follow: we first introduce two new tax bases, in this area the environmental and local taxes are provided, the second reform is to improve the performance of the available tax bases, include direct and indirect taxes, in this area two tax bases include global income tax and VAT are presented. Finally, in respect to implementing policies related to economic evolution project, especially in the energy sector, essential tax policies for saving energy are provided.

According to Piketty’s point of view, the rate of income from wealth is always higher than the rate of economic growth, and the share of national income that belongs to capital is always more than the share of labor force. Therefore, inequality increases systematically and increasingly. The solution to this problem is to impose a maximum tax on wealth. Therefore, the tax on the components of wealth was imposed with the aim of reducing inequality. In Iran, this type of tax is collected from different components of wealth. Therefore, this research was conducted with the aim of investigating the impact of wealth tax on income distribution in Iran. For this purpose, a model was estimated in which the Gini coefficient was the dependent variable and the wealth tax and income tax were the independent variables along with the unemployment rate. Estimates were made using the time series data of 1991-2018 with the help of the Johansen-Juselius cointegration method. The results showed that there is a negative relationship between wealth tax and Gini coefficient. So that a one percent increase in wealth tax reduces inequality by 0.729 percent. The results showed that the speed of impact of wealth tax policies on income distribution is very slow, so that applying a change in wealth tax every year shows only 12% of the total impact on inequality.

Due to the adverse consequences of inflation in different sectors of the economy, the awareness of the possibility of hyperinflation in the near future makes a great opportunity to avoid the occurrence of hyperinflation. Therefore, this research seeks to design a warning system for hyperinflation. This system using the variables affecting inflation and exploiting the basics of the neural networks appraises the possibility of the occurrence of hyperinflation in the next six months. In this research, from the monthly data of 21 possible variables having effect on inflation from March in 1996 to December in 2011 with the combination of genetics’ algorithm and neural networks the essential variables affected Iran’ inflation are determined. These variables are: Liquidity, government expenditure, labor wage index, interest rates, gross domestic product, Inflation with a lag, and global price index for crude oil. After identifying the fundamental variables using the data related to these variables, the designing of a warning system for inflation is sought. To design such a system, a feed forward neural network with two hidden layers is used. The experimental results of the model indicate the promising performance of the warning system, and the system is able to emit an early warning signal for the occurrence of hyperinflation in near future.

EXTENDED ABSTRACTINTRODUCTION shadow economy is an integral part of the economic structure of any country, which is always more common in countries with lower levels of development than in developedones. A relatively large size of shadow economy will have many negative effects on the economy as a whole because it absorbs resources and labor from the formal economy, limits public resourcesandthe effectiveness of policies, and distorts official statistics, as well as competition. It will increase unfair competition against official companies that follow the rules. Therefore, in order to prevent, identify and deal with this phenomenon, the government must bear the costs. Considering that increasing military expenditures with the security it creates inside each country causes the injection of domestic and foreign capital into official sectors of the economy and increases employment and GDP, as a result of the security caused by increased costs in the military sector social order, economic prosperity, peace of society, increasing creativity and innovation, progress and development of society, access to modern and advanced facilities and equipment, and finally reducing economic crime and underground and shadow activities in the country will happen.During the period under review, shadow economy as a percentage of GDP in Iran has an upward trend with relatively low ups and downs and during this 35-year period has an average of 19.31 percent and the variable of military spending as Percentage of GDP has a negative and significant effect on the shadow economy in the period under study, ie for each unit of increase in military spending shadow economy decreases by 0.134 percent. METHODOLOGY In this research, the structural equation modeling approach based on partial least squares and multiple index pattern - multiple causes and SMART PLS software has been used to investigate the effect of military spending on shadow economy in Iran during the period 1981 to 2015.Multiple Index Pattern - Multiple causes, which include observed model variables and latent shadow economy variable, take the form of two equations. In the first equation, the relational relationship of shadow economy and its causes are explained and in the second equation, how the indicators are affected by the volume of shadow economy is specified. Therefore, the multiple index model - multiple causes has two parts: structural model and measurement model. The mathematical formulation of the template is as follows:(1)                                                                                     (2)                                                                                       η: hidden variable (shadow economy); X: vector (q × 1) causes in the structural model; Y: Vector (p × 1) of indicators in the measurement model; λ: (p × 1) coefficient matrix in the measurement model; γ: (q × 1) The cause coefficient matrix in the structural equation v: error in the structural model and 𝜀: a vector (p × 1) measurement error in YThe regression form of the structural equation is:The regression form of the measurement equation is as follows:(4)                           As can be seen in the structural equation and the measurement equation, the variables of military expenditure (me), effective tax rate (etax), formal market exchange rate (racmi), black market exchange rate (unracmi), economy openness (open), Revenues from natural resources (oilindex) and government size (gov) as the reasons for measuring the shadow economy as well as the variables energy consumption (energy), money demand (dmoney) and employment (employ) as the effects of the shadow economy have been selected to estimate the model. FINDINGS According to the results of this study, the signs of coefficients of exchange rate variables in the formal market, government size, effective tax rate, income from natural resources, military expenditures and the openness index of the economy in the study model are statistically significant and coefficient signs are consistent with theoretical predictions. Also, the estimated values of parameters in the studied model show that among the indicators reflecting the effects of shadow economy, the effect of shadow economy on energy consumption and money demand is positive and is as expected. CONCLUSION The results of the analysis showed that increasing military spending to create the necessary infrastructure for the production of military equipment in the country instead of buying it from abroad, while reducing the country's military dependence on the world military powers, creates employmentand economic prosperity, increases national income and reduces unconventional and shady activities. Of course, it should be noted that although military power is a factor in ensuring internal security and reducing external threats, due to budget constraints, unconventional increase in military spending and replacing it with other public sectors spending such as education, health, etc. is an obstacleFor Optimal allocation of income to economic and social investments, which will have adverse consequences. In addition, official exchange rate, income from natural resources, economy openness index, black market exchange rate, government volume and effective tax rate are among the factors affecting shadow economy in Iran, among which the variable of income from natural resources has the most effecton the expansion of shadow economy. shadow economy has also affected energy consumption, money demand and employment, which have a greater impact on employment as a whole than on the other two variables. Therefore it is suggested:1- Organizing a business environment with the aim of directing activities in the field of informal economy to the formal sector of the economy and increasing economic transparency 2- Explaining the effect of military spending on security and life of citizens to motivate tax payments and prevent the spread of shadow economy.3- More control on the budget, especially the military budget to prevent possible abuses. 4-Based on results, increasing liquidity results in inflation which itself brings forth shadow economy. Implementing appropriate monetary policies as well as financial order can prevent inflation and its detrimental consequences.

The tax system as a subset of the economic system serves the purposes that the economic system pursues. On the one hand, the goals of each system are based on the assumptions and values of each school, and therefore the fundamental function of tax systems cannot be more discrete than the underlying issues. The tax system of the Islamic Republic of Iran has witnessed changes in tax structures in recent years. A better understanding of the nature of the Islamic tax system and its functions may help to formulate and shape a more Islamic tax system. This paper examines the functions of a favorable Islamic tax system in comparison with the functions of the conventional economic tax system, using the content analysis approach, and therefore proposes some considerations for value added tax. This article uses the content analysis method of the functions of the favorable Islamic tax system in comparison with the functions of the tax system of the conventional economy and then, based on it, points about substituting the tawazon criterion in Islamic economic justice, tax principles, tax rates and bases, and share of taxes in government revenue sources. According to the Islamic policymaker, who considers justice as the basis of organizing society, taxes are also a tool for this purpose, and taxes that are compatible with achieving economic balance are considered appropriate. The balance criterion is considered in all the initial, process and final stages and the increase of tax revenues is followed by using justice-oriented methods and tax revenues can never be increased at the expense of justice. Also because in the economic system. Islam has part of the resources of wealth production (Anfal) at the disposal of the government.

The historical trend of Iran’s economy shows that the most important source of financing investment has essentially been borrowing from the banking system, while borrowing from the capital market and other sources has contributed minimally to the financing of enterprises. However, imbalance in the banking system, as an important factor, can play a destructive role in financing investment and enterprises, causing banks to have a lower lending capacity for investment and production. This study seeks to evaluate the effect of banking system imbalance on economic growth across different sectors of the economy within the framework of an econometric model using the simultaneous equations system method. For this purpose, data from various sectors of Iran’s economy during the period 2001–2022 were employed. The results indicate that banking system imbalance has a negative effect on the financing of different sectors of the economy by the banking system. Moreover, given the positive and significant effect of financing from the banking system on investment and the positive and significant effect of investment on value-added growth across different sectors of the economy, banking system imbalance exerts a negative impact on the level of activities in economic sectors and emerges as a constraint. In addition, the findings reveal that the real interest rate of granted facilities has no effect on credit demand, financing from the banking system, or investment in economic sectors, while it plays a role in eliminating banking system imbalance. Accordingly, monetary policymakers must take serious measures to eliminate banking system imbalance and to signal interest rates within the economic and monetary system.

Introduction: 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. Methodology: 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. Results and Discussion: 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. Conclusion: 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.