نشریه اقتصاد و تجارت نوین
سال شانزدهم شماره 4 (پیاپی 53، زمستان 1400)

The retail electricity market is the intermediary between end-user customer and the wholesale market to supply customers’ energy. One of the basic tools in interaction between the retailer and the end-user customer is use of demand response programs. In this research, a business-economic model with the aim of maximum interaction between retailer and other electricity market players based on interval optimization and demand response programs is proposed to achieve an optimal decision of retailer in bilateral contracts and the pool electricity market. This proposed model calculates the retailer's profit before and after the implementation of appropriate demand response program and ultimately maximizes the difference between these two values. The results show that by using price-based demand response programs and price elasticity of each customer, maximum participation of customer in reducing peak load of the power grid can be achieved. On the other hand, based on proper modeling of uncertainties such as price elasticity and pool electricity market prices, the retailer's profit will increase with a suitable level of risk. For retailer profit, it can be concluded that based on application of fuzzy and epsilon constraint method, determining an optimal pareto points and retailer profit maximization will occur in real time pricing tariff compared to time of use pricing tariff . From the maximum interaction point of view between the retailer and the end-user customer in the electricity market based on the current research, the preferred policy is the policy of using intelligent methods of price-based demand response programs.

The issue of the budget deficit and its aggregation in the form of debt accumulation has always been a concern in scientific and policy circles. The accumulation of government debt can affect investment and thus economic growth, and this effect can vary in different economic conditions. The purpose of this paper is to investigate the relationship between government debt and private sector investment with emphasis on the effect of debt accumulation in this regard. The results of this model show that, firstly, the relationship between government debt and private sector investment is negative, and secondly, as government debt increases, the impact of government debt on private sector investment decreases. Therefore, enlarging the government at the expense of increasing borrowing cannot have a positive effect on the activities of the private sector. Also, the impact factor of inflation and oil revenues on private sector investment is negative and positive, respectively, and the impact factor of both is significant. In addition, all good fit tests in the model were examined. The results of the studies showed that the model is reliable in terms of these tests.

Portfolio optimization is one of the main methods of investment and one of the main stages of portfolio construction. Since ptimization is the process of selecting the best option from a set of available options, given specific constraints, this is one of the most important challenges facing investors, financial managers and operations research modelers. In this paper, the optimal portfolio curvature with criteria of variance risk (MV), absolute deviation (MAD) and conditional value at risk (CVaR) for the five symbols Shasta, Kachad, Vepars, Khsapa and Shebandar is obtained from 1/09/1399 to 1/3/1400 and all four methods are compared. Accordingly, the effect of skewness and kurtosis on optimal portfolios in all four risk criteria is investigated by applying the dependence structure of copula functions using Monte Carlo simulation. In this regard, Pearson distribution system and Gaussian copula have been used to simulate the yields with different skewness and kurtosis and with standard deviation and mean of historical data, and finally it is shown that this process leads to a change in the optimal portfolios in all four methods of portfolio optimization, so that the change in the amount of presented risk causes the most change in the optimal portfolio of CVaR and the least change in the optimal portfolio MSV.

In this research, the data-output model of two regions in order to measure and analyze water and energy relations between the economic sectors of Isfahan and Yazd and the link model to investigate the hybrid flow of two sources and the extent of link effects in each region in 2011 Used. The analysis shows that the two sectors of "water, electricity and gas" in Isfahan province and "manufacturing of non-metallic mineral products" in Yazd province are known as the most consumed sector in the field of energy consumption. Also, based on the estimated results in the present study, the "agriculture" sector in both provinces is known as the most consumed sector in the field of water. The results of combined energy and water flow show that the two sections "Making non-metallic mineral products" and "Agriculture" in Yazd have the largest hybrid energy and hybrid water flow, respectively. It has hybrid water. Regarding the analysis of the total energy and water flow between sectors in two regions, it can be mentioned that in Isfahan province, the two sectors of "basic metals" and "coke production, products from refining oil and nuclear fuels and manufacturing of chemical materials and products" as Important sectors in the field of export and import between the energy sector and the sectors of "agriculture" and "other services" in the field of export and import between the water sector are known. In the field of water resources, the "Agriculture" and "Other Services" sectors are the largest exporters and importers, respectively, and are known as the key sectors of Yazd province for the management of energy and water resources.

Air transport is one of fundamental sub-sectors of transport services, which has a high value added and novel technologies. On the other hand, due to the importance of employment, this article examines the effects of factors of production on employment in the Iranian air transport industry. For this purpose, the CES function has been used to examine employment. Workforce is introduced as dependent variable and value added, wage and capital price are considered as independent variables in the model. Research period - years 1382 to 1397 (2003 to 2018) is considered as time series for the extracted data of the air transport industry of Iran and the mentioned Econometrics model is estimated by Autoregressive distributed lag model (ARDL( and with a boundary test approach. Boundary test result, confirms correlation among the variables, which shows long-term relationship between the research variables and this is interpretable. Result of the long term model estimation shows that the estimation index for the variables (value added, wage and capital price) are statistically meaningful and their values are 0.16, 0.62 and -0.23, respectively. Result of the long term model estimation shows that the estimation index for the variables (value added, wage and capital price) are statistically meaningful and their values are 0.16, 0.62 and -0.23, respectively.

In this study, the factors affecting financial development with emphasis on oil rent and institutional quality for a selection of oil exporting countries during the years 2002-2018 have been investigated using the GMM dynamic panel method. For this purpose, the multidimensional index of financial development of the International Monetary Fund and the index of good governance have been used. Findings show that oil rent has a negative effect on financial development, access to financial institutions and markets, depth of financial institutions and markets, financial market efficiency and a positive effect on the efficiency of financial institutions. Institutional quality also has a positive effect on all aspects of financial development, including the development of institutions and markets. Inflation is inversely related to financial development, access and depth of financial institutions, depth and efficiency of financial markets and directly related to efficiency of institutions and access to financial markets. GDP in the countries under study has a negative effect on all variables except the efficiency of financial institutions and population density has a positive effect on all dependent variables except access and efficiency of institutions and efficiency of financial markets. As a result, it is suggested that governance indicators be improved to achieve financial development and with proper management of oil resources to prevent its adverse effects.