فصلنامه تحقیقات مدلسازی اقتصادی
سال یازدهم شماره 41 (پاییز 1399)

The importance of non-oil exports and their role in the economic growth and development of countries has always been discuss as an important issue in the economy. Meanwhile, the role of high-tech exports in the growth of developed countries has been significant and developing countries, in order to succeed in the growth of production and export of their industrial goods under the constraint of globalization, have no choice but to increase production and export of high-tech products, use more advanced production techniques and save on production costs. This is especially true in the case of Iran, which has always faced the problem of macroeconomic indicators due to its dependence on oil revenues and the destructive impact of oil revenues on political and economic issues, especially the issue of oil sanctions. In this regard, the aim of the present study was to investigate the factors affecting the export of high-tech products based on the four-digit ISIC codes in Iran in the period 1397-1375 using the ARDL Panel method.The results of the study show that the costs of domestic research and development, foreign accumulation of research and development and commercialization in the short and long term, and the degree of openness of the economy and human capital in the long run have a positive and significant effect on high-tech exports in Iran. Also, the exchange rate in the short term has no meaningless effect and in the long run has no negative and significant effect, and inventions in the short and long term have no significant effect on the export of these products.

Rice is the second strategic product after wheat and one of the most widely consumed food products in the country. Population growth, consumption and growing demand, price fluctuations and welfare effects due to changes in the amount and price of rice require the attention and planning and foresight of policymakers and the countrychr('39')s planning system. In this study, in the framework of inverse demand system, rice types (foreign rice 1 and 2 as well as four types of domestic rice) using cross-sectional data related to consumption and expenditure of urban households during the years 96-1392 were estimated by seemingly unrelated regression estimation (SURE) method. And from 4 systems of reverse demand IADIS, IROT, INBR and ICBS Only the inverse demand system IADIS It is compatible with the data of the research method and according to the results of the statistics, the correlation ratio is superior to the other three models In order to study the welfare effects, four scenarios were defined and by compensating the compensatory and equilibrium effects and combined changes were determined.  Due to the share of more than 60% of first grade foreign rice and second grade foreign rice in the expenditure share of urban households, a change in the amount of consumption of this type of rice compared to domestic rice can have a more significant impact on household welfare. The results of changing the values of different types of rice on their prices in the form of different scenarios showed that if the consumption values of imported rice decrease, the price of this rice will increase. However, the rate of price change for different types of rice is not the same, and its intensity depends on the amount of traction and the scale of each. On the other hand, the demand for different types of rice will increase in the future for various reasons, including population growth, which if this increase in demand is not accompanied by an increase in market value, will increase the price of various types of rice.

Reducing or eliminating subsidies for the electricity sector in the economy is a good way to control the daily consumption of electricity and balance the cost of supply and demand players. By increasing or decreasing electricity subsidies, indirect taxes are reduced or increased. Under these conditions, assuming the stability of primary inputs and the stability of power generation technology and based on input-output modeling, the effects of rising electricity prices on the prices of manufactured goods in the 75 economic sectors were measured. The results of this simulation, which was performed under three models of electricity price increase of 7%, 16%, and 23%, show that the "communications", "manufacturing of food products" and "manufacturing of non-classified non-metallic mineral products" sectors are the highest. Taking into account the total benefits of increasing the price and its socio-economic costs for residential subscribers, the scenario of "increasing the tariff price of residential subscribers by 7%", "increasing the tariff price of public consumption by 16%", "increasing the tariff price of Water and Agriculture Production subscribers by 16%", "Increasing the tariff price of Industrial and Mining Production Subscribers by 23%" and finally "Increasing the tariff price of Other Uses Subscribers by 23%" can be a proposed tariff in increasing the price of electricity.

Systemic risk arises from simultaneous movement or correlations between market segments; Thus, systemic risk occurs when there is a high correlation between the risks and crises of different market segments or institutions operating in the economy, or when the risks of different segments in a market segment or a country are related to other segments and other countries. This paper presents a measure of systemic risk calculation to effectively describe the systemic importance of each financial institution in a system. The DCC-GARCH methodology with normal and t-student distributions has been used to examine the correlation of time-varying banks. The results of this section show that the application of DCC-GARCH-student-t model is preferable to DCC-GARCH-normal model. In order to investigate the presence of leverage effect, GJR-GARCH model was used and the results of estimation showed the presence of asymmetry and the absence of leverage effect in the data. In the study of dynamic conditional correlation between selected banks, it is also observed that α_C  ,β_C are not significant for both estimation cases. Therefore, in both cases, it is estimated based on the normal distribution and t-student α_C=β_C=0 and the conditional correlation becomes constant. Based on the results of shapley value and in order to allocate the total risk between the banks in the sample, Parsian, Mellat, EN, Tejarat and Saderat banks have the most systemic importance for the period of June 17, 2009 to May 7, 2019.

Volatility is a measure of uncertainty that plays a central role in financial theory, risk management, and pricing authority. Turbulence is the conditional variance of changes in asset prices that is not directly observable and is considered a hidden variable that is indirectly calculated using some approximations. To do this, two general approaches are presented in the literature of financial economics for modeling and calculating volatility. In the first approach, conditional variance is modeled as a function of the square of the past shocks of return on assets. Models of the GARCH type fall into this category. In the alternative approach, volatility is assumed to be a random variable, which evolves using nonlinear patterns of Gaussian state space. This type of model is known as Stochastic Volatility (SV).  Because, SV models include two kinds of noise processes, one for observations and another for hidden, volatility, thus, they are more realistic and more flexible in calculating volatility than GARCH type.  This study attempts to analyze the volatility in stock returns of 50 companies, which are active in Tehran Stock Market using symmetric and asymmetric methods of Stochastic Volatility, which is different in the presence of leverage effect. The empirical comparison of these two models by calculating the posterior probability of accuracy of each model using the MCMC Bayesian method represents a significant advantage of the ASV model. The results in both symmetric and asymmetric methods represent the very high stability of the volatility generated by the shocks on stock returns; therefore, the Tehran Stock market changes in returns due to this high sustainability will be predictable.

Some unique characteristics of housing goods such as spatial dependency, heterogeneity and durability make housing market analysis different from ordinary goods. However principles in ordinary goods market such as profit maximization are used by developer in housing market. one of the housing market characteristic is that land as a most important input for housing services production has low demand elasticity because of its scarcity. This always makes housing services developer in housing market to substitute capital (construction materials) instead of land. In economics, for demonstrating this kind of substitution, elasticity of substitution is used. Since land has a local market and the intensity of scarcity in cities is different so there are different numbers for elasticity of substitution in different cities and regions. This paper is trying for estimating elasticity of substitution n a median city by gathering data survey. The results show elasticity of substitution between land and capital in housing services production in city of Dorud is 1/04 percent in 2018.