فصلنامه مدلسازی اقتصادی
سال پانزدهم شماره 2 (پیاپی 54، تابستان 1400)

The purpose of this study is to apply the system dynamics approach to predict the price of gold in Iran, identify factors affecting the price of gold and simulate the impact of monetary policy on the price of gold in the period 1389-1405. The simulation was performed with Vensim software. The present study simulates the change in liquidity volume, consumer price index and bank interest rates on the gold market in different scenarios. The results show that the price of gold is not only affected by the gold world price and the value of the dollar, but also the control of liquidity and curbing inflation will play a significant role in stabilizing the gold market. The results confirm that the volume of liquidity and the consumer price index have a direct impact and a significant role in increasing the price of gold. The findings also show that changes in bank interest rates have no effect on changes in gold prices.

One of the most important issues in public sector economics is the formulation of compensatory policies and pricing of energy carriers.The purpose of this study is to estimate the income and price elasticities of energy carriers for urban households in Iran. Therefore, the demand system of energy carriers including "gasoline", "household electricity" and "household gas" for urban households has been estimated by the pooled data of "household-year" with 77758 households during the period 2016-2019. This estimate is made in two cases: all urban households and households that have consumed gasoline.One of the distinguishing features of this study compared to previous studies is the use of monthly price index data with cross-sectional household budget data. The results show that "gasoline", "household electricity" and "household gas" are essential. Also, gasoline and household electricity are inelastic and household gas is estimated to be elastic.

Saving electricity consumption, especially in the household sector, is essential given the growth of electricity consumption in this sector. One of the most important ways to save electricity is to improve the efficiency of electricity consuming devices, but there is a close relationship between improving the efficiency of electricity consumption and the rebound effect, which if ignored, will have adverse effects. In the present paper, using the ordinary least squares method, the size of the direct rebound effect related to electricity consumption in the household sector of Iran has been estimated in terms of asymmetry in electricity prices. For this purpose, and considering the separation of electricity prices based on the Gately study, annual data for the period 1347-1398 and estimating the elasticity of electricity demand have been used. The results show that, firstly, improving the efficiency of household electricity consumption has a rebound effect. Secondly, the rebound effect in the household sector is 43%. With a 10% upgrade of household appliances technology, 4.3% of the expected reserve due to the improvement of electricity consumption efficiency does not occur and appears in the form of a rebound effect, and only 5.7% of the expected reserve in electricity consumption is realized.

productivity is one of the important concepts in the economy, showing the relationship between the use of production factors and produced products. by increasing productivity in the production process, more production can be achieved by using a certain level of input in this study, the effect of economic sectors efficiency on renewable and renewable energy consumption, thermal energy, growth and economic development using approximation of production functions have been studied in three scenarios. the results show that the different parts of totall economic and their productivity in 1353 and 1393 are between 3.175 and 4.59 million riyals. It is therefore the beginning of the productivity of the lower bound productivity of the functional domain.it is observed that there are two sectors of economy, industry, mining and power plants (power plants), even by 30 percent, the overall productivity of the entire economy in the functional domain (3.175).

In this study, the effect of the comparative advantage of different activities on the economic growth of the provinces in the period 2004-2014 has been evaluated. For this purpose, using the statistics of the statistical yearbook of the Statistics Center of Iran and the regional accounts of the Central Bank for 30 provinces, the desired indicators have been calculated. Then, in the form of a dynamic panel model, using the generalized two-stage nonlinear torque technique (GMM), the effect of the comparative advantage of major activities on the economic growth of the provinces is estimated. The results of estimating the models confirm that the three major sectors of agriculture, construction and services have a positive and significant effect on economic growth. The industry, mining and energy sectors have a negative effect on growth. This negative impact can be due to the greater impact of other sectors on growth.

The purpose of this paper is to investigate the interrelationships between transportation (rail and air), economic growth and CO2 emissions in Iran during the period 1983-2019 using time series data and simultaneous equations system. The findings show a positive correlation between transport (rail and air) and economic growth, as well as between transport (rail and air) and CO2 emissions. Another finding of this study is that economic growth has a significant effect on increasing CO2 emissions, however increasing CO2 emissions has no effect on economic growth. Based on the results, the creation and development of infrastructure related to the type of transportation in order to improve the economic growth of the country is proposed.