فصلنامه برنامه ریزی و بودجه
پیاپی 153 (تابستان 1400)

The optimal pricing of goods and services is one of the most challenging issues in economics. Scarcity of resources which causes a good or a service priced more expensive, on the one hand, and its costs of production on the other, motivate researchers to find optimum price. This paper investigates an optimal pricing scheme for Iran’s IXPs services including 1Ge ports, 10GE, and 100GE ports through a Fuzzy Geometric Programming model. “Internet exchange points” (IXPs) are infrastructures through which Autonomous Systems (AS) such as Internet Service Providers (ISPs), Content Delivery Networks (CDNs), Content Providers (CPs), and other internet networks, peer with each other to exchange internet traffic more efficiently. These points provide their members with a wide variety of services. How should these services be priced so that the maximum number of potential members can be connected to IXP and also the profit of IXP is maximized? The FGP model answers these questions. According to the results of this paper, the demand for the services of IXPs is a function of the price of ports and the number of services provided in each IXP. This demand function is normal; i.e., the quantity demanded has a negative relationship with the port price and a positive relationship with the number of services. The demand function for 1GE ports is price inelastic, while the elasticities of the price for 10GE and 100GE is greater than 1. Also, it has been shown that the optimal price of the Iranian IXP services based on the FGP model proposes a higher price of 10.3% compared to its current price, and a lower price for 10GE and 100GE ports of 1.75% and 14.5% respectively compared to the current price. The sensitivity analysis shows that the changes of price elasticity up to 90%, have no impact on the profit of IXP, but it has a small effect on the optimum price.

The chemical industry has one of the largest production value chains, and the products of these industries are widely used as intermediate goods in other industries. In this paper, as regards cost function, Allen's elasticities and own elasticities, price elasticities, Morishima elasticities, energy elasticity, and scales of economics have been estimated in seven selected activities of the chemical industry using statistics and information 2002(2)-2018(1). The results show that the average share of employment, wages, output, and energy of the chemical industry in the entire industrial sector are equal to 6.38, 8.41, 13.28, and 17.45% percentages, respectively (in the period under review). In manufacturing of fertilizers and nitrogen compounds, plastics and synthetic rubber in primary forms, man-made fibers, soap and detergents, cleaning and polishing preparations, perfumes, and also cosmetic preparations, changes in energy input prices affect production costs more in comparison with changes in the prices of other inputs. In all seven selected activities, capital stock demand is more sensitive to changes in its price than other input. In addition, the amount of cross-demand hedges are mostly small. In manufacturing of basic chemicals, fertilizers and nitrogen compounds, paints, varnishes, and similar coatings, printing ink, mastics, and man-made fibers, the price elasticity of natural gas is higher than other types of energy. In the manufacturing of other chemical products, soap and detergents, cleaning and polishing preparations, perfumes, and cosmetic preparations, and plastics and synthetic rubber in primary forms, the price elasticity of electricity is higher than other inputs. Furthermore, the selected activities in this study have increasing returns to scale, thus the larger units of which are preferable to the smaller units.

Transmission of gas from extraction wells is a precondition for transferring this resource to consumers, which in turn requires a comprehensive system in production, transmission, and distribution. The transmission cost varies depending on the transmission distance, route difficulty, number of stations, and decrease or increase in pressure. Hence, concentrating on another energy resource with low investment requirements that could be delivered for consumption at the production area can lead to reduction in costs and time efficiency as well. The present study attempts to compare the combined solar wind power plants with the gas transmission, in terms of cost and revenue in Andica county, located in Khuzestan province, using simulation tools for renewable power plants. The findings suggest that combined power plants have significantly lower cost than gas transmission power lines in terms of investment requirements. The operation cost of gas transmission lines has a significantly higher price in relation to its ensuing revenue, since the operation costs of combined power plants are covered by annual revenue from the electricity supply. In general, it should be said that the high cost of capital for gas transmission, considering the annual income from its sale, refutes its economical profit, while the combined power plant, due to the lower cost of capital than gas transmission, produces more revenue than gas sales, so it is more economically justifiable than gas transmission.

Policymakers attempt to improve the market quality of stock exchanges by implementing various regulations. Even though the transaction tax has always affected exchanges, the consequences of such policy on various aspects of market quality have often been understudied in Iran. Thus this paper, using high-frequency data of 422 companies in the period from June to November 2018, investigates the effect of reducing transaction tax in different quality measures of Tehran Stock Exchange. Considering the fact that reduction of transaction tax in September 2018 has not been applied to investment funds, the DID approach has been implemented. According to the results, the reduction of transaction tax in September 2018 has increased the volume of transactions and market efficiency, while market volatility has decreased in effect. This result, therefore, confirms the liquidity versus composition effect through which the reduction of transaction tax increases the market efficiency by an increment of liquidity.

Prediction is one of the most important premises in making investment decisions. Accordingly, investors are keen to be aware of market trends and price returns. For this purpose, several methods have been used in different fields; however, in the present study, the ability to predict the crisis by Cumulative Residual Entropy (CRE) and its generalized type, Fractional Cumulative Residual Entropy (FCRE), has been investigated. The data used in the research include the overall index, volume, trade value, and foreign exchange rate from October 2010 to July 2021. The results showed that both criteria could predict the crisis, but the FCRE is superior in crisis prediction. The identified periods of crisis are 2011-2012, 2014-2016, 2018-2019, and 2020. Each of the crises, including the recent Covid-19, was analyzed and investigated.

The aim of this study is to test the validity of the Kuznets Environmental Curve (EKC) hypothesis for Iran. For this purpose, this study used the FourierARDL method and causality test with time change to analyze the short-term and long-term relationships between economic growth, economic complexity index, energy consumption, and ecological footprint. Findings from the Fourier ARDL approach confirm the existence of coherence between variables. In addition, the results of this study show that energy consumption and economic growth increase the ecological footprint in the short and long term. However, the short-term elasticity of economic growth is smaller than the long-term elasticity, meaning that the EKC hypothesis is not valid for Iran. This finding is confirmed by the causality test with time change. The overall results show that economic complexity has a diminishing effect on the ecological footprint and economic growth is not effective in solving environmental problems in Iran. Therefore, the Iranian government should encourage an environmentally friendly production process and cleaner technologies in exports to reduce environmental pollution.