نشریه اقتصاد و الگوسازی
پیاپی 47 (پاییز 1400)

Increasing economic integrity and expansion of trade across countries have caused international movement of production factors in order to achieve higher income. According to Mundell's theory (1975) and based on traditional theories of trade, unequal and different endowment of factors of production in countries cause the establishment of trade and the movement of factors, until reaching the equalized factor endowment. In other words, factors movement is a substitute for trade, although in most cases the empirical evidence reveals different and sometimes contradictory results to Mandell's theory. The present study investigates the effect of trade liberalization on the international movement of skilled and unskilled labor in Iran. Accordingly, trade liberalization is stimulated through four scenarios of import tariffs reduction of 5%, 10%, 25% and 50% in agricultural, industrial and the whole imported goods by using Global Trade Analysis Project. The findings of this research indicate that there is a complementary relationship between the liberalization of industrial and all imported goods with the mobility of skilled and unskilled labor. However, trade liberalization in the agricultural sector and skilled labor mobility are a complement, they are substitutes in terms of the unskilled labor movement.

In this study, using portfolio theory and the risk content of exports models and risk- weighted comparative advantage (RiskCA), the risk and diversification of Iran's non-oil export portfolio are analyzed. In fact, each of the export commodity sectors is considered as an asset and its variation in the export structure are calculated as the content risk of exports. In this regard, using export data during the period 1988-2019, the diversification index of Iran's non-oil exports has been measured based on the overall difference measures. Also, the risk- weighted comparative advantage is calculated and its relationship with the risk content of exports and export diversification index using nonparametric estimation and semi-parametric and analyzed by Matlab programming. According to the results of this research, the relationship between the degree of export diversification and the risk of the risk- weighted comparative advantage (RiskCA) is U-shaped. This means that if there is a comparative advantage in the safe export sectors of the country, it will choose fully specialized. Exports will specialize in high-risk sectors if the comparative advantage is strong enough. However, in intermediate values of comparative advantage, the export will diversify between risky and risk-free sectors and an optimal combination solution is selected.

One of the basic assumptions in input-output tables is the assumption of technology stability and consequently the stability of production multipliers. In this study, using a proposed approach based on the RAS update method, we show that how an exogenous policy shock such as rising gasoline prices changes production multipliers compared to an economic modeling with updating on a Standard RAS. Unlike the conventional RAS method, in addition to changing the technological structure of production due to gasoline price shock, in order to link household consumption and income of production factors, value added and final demand are adjusted based on gasoline price shock and thus the relationship between household income and consumption and its connection with the price is highlighted. To provide value-added adjustment scenarios and final demand, an increase in the price of gasoline from 10,000 rials per liter to 30,000 rials has been considered. In this research, the input-output table of the Central Bank of Iran in 2016 has been employed. The findings of this study indicate that due to the increasing the price of gasoline, the production multipliers for all economic activities except gasoline have been reduced using the proposed method compared to the standard RAS model. Examination of the results obtained for the total cost of production and output of all economic activities also shows that the highest increase in production cost and the lowest decrease in total output is related to gasoline.

Urban public transport demand response to various internal and external shocks is one of the most important issues in urban public transport policymaking. The purpose of this study was to investigate the spillover effects of demand for urban public transportation in Tehran megacity using Global Vector Autoregressive (GVAR) Approach during period from 2008 to 2019. The results of the impulse response function analysis indicated that the occurrence of a positive shock in metro demand increases the demand for BRT and decreases the demand for bus. Moreover, a positive shock in bus demand declines the demand for metro as well as BRT simultaneously. The occurrence of a positive shock in BRT demand leads to the increase of metro demand and reduction of demand for common bus. Besides, a positive shock in metro fares decreases the demand for both BRT and common bus while a positive shock in bus fares increases the demand for metro and BRT. When a positive shock occurs in BRT fares the demand for metro increases while the demand for bus and BRT increases gradually. Also, a positive shock in gasoline price leads to the increase of demand for all three types of public transport modes. Moreover, with a positive shock in income per capita, metro demand will remain stable, bus demand will increase while BRT demand will decrease. Finally, the occurrence of a positive shock in the unemployment rate would lead to the increase of demand for metro and BRT and the reduction in demand for bus.

Resource constraint as the main issue in economics, warns of the need to prioritize the use of available resources, therefor identify the key sectors of economy is one of the important concerns for economic planners and politicians. the purpose of this study is to identify key sectors of ISFAHAN province. therefore, the national input- output table for 2011 was prepared based on the SFLQ method in twenty sections for ISFAHAN province and other national economies in two regions. then, by traditional methods, final output demand elasticity and data envelopment analysis, the key sectors are identified. finally, a simultaneous definition of the result is provided using multi-rank index (MRI). the results show two important points. the first point: differences in the key sections of each region indicate the importance of attention to the regional planning approach, which will invite to the proper understanding of the potentials and capabilities of each region. the second point: due to differences in the results of the methods used in identify key sectors, its necessary that the relevant studies should not to just one method and the appropriate method due to the policy and planning goals. in a summary of the results, key sectors of ISFAHAN province is industry oriented.

By the self-sufficiency in production of essential refining products (e.g. gasoline, gas oil) in Iran, always there has been a constant debate about constructing new refineries or exporting oil in crude form instead. On the one hand, refineries are vital for modern life but on other hand, Refining is a capital-intensive and low profit industry; because of these, it’s always been difficult to make decision in dilemma of constructing new refineries or exporting crude. Due to this, in this research will be tried by presenting a theoretical framework, be assist in making better decision about refinery construction. Our method in this research is Cost-Benefit Analysis(CBA) that in addition of financial view contains the economic point of view and also as the case study, the Siraf refineries complex is chosen. The results indicate that, despite the advantage of Siraf, the full feasibility doesn’t approved; but by regarding the economic view, feasibility increases meaningfully. In financial model, project is feasible in 3 scenarios (out of 5) whereas; in economic model, project is feasible in every 15 scenarios. In economic model besides using shadow prices, the externalities (energy security and environmental effects) has monetarized. By considering the results, in current consumption and production conditions of refined products, stablishing a new refinery leads to more welfare for society; accordingly stablishing Siraf is recommended.