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As one of the most important products of Iran, pistachio has a significant share in non-oil revenues. Its annual foreign exchange earnings are over 800 million dollars. However, production of this nut in the country’s major production centers is faced with many problems regarding the efficiency and productivity of the inputs. This study was performed by using two-stage cluster sampling method. The results showed that with the increase in energy carriers’ prices, the farmers of the region would tend to use the optimal amounts of inputs in the long term, thus, reducing energy consumption from 46,016.72 to 31,092 MJ ha^-1. Also, the present values of energy productivity, its efficiency, and specific energy of, respectively, 0.03, 0.42, and 35.05 MJ kg^-1 would be optimized to 0.07, 1.10 and 13.47 MJ kg^-1. Besides, it was revealed that the net energy, which was negative under the existing condition (-26,532 MJ), would increase to 3,160 MJ following the increase in the price of energy carriers. Above all, the non-renewable energy consumption would be reduced from 39,743 to 26,457 MJ. Of course, to achieve the mentioned results, government support of farmers in the short term is necessary in order to facilitate and expedite the change in technology.

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Energy carriers including elasticity play central roles in development of societies. In this paper, we estimate residential electricity demand among the selected counties of Tehran province, i.e., Tehran, Varamin, Firouzkooh, Damavand, using dynamic panel data model over the period 2000- 2014. The most effective variables which explain demand for residential electricity are per capita income, natural gas real price, weather coldness and hotness index and electricity real price. The estimation results of the short run model reveal that demand for electricity decreases by 0.42 percent for one percent increase in electricity real price. The price of substitute energy carrier such as natural gas is of low effect on electricity demand. There is a positive and significant relationship between electricity demand and household's income. The last period electricity demand is the key effective factor in explaining the current electricity demand with a coefficient of 0.65. The estimation results of the long run model show that one percent change in electricity price changes the demand for electricity by -1.2 percent. In addition, demand for electricity increases by 0.1 percent with one percent increase in income.
 

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Agriculture is one of the responsible sectors for adequate food production and contribution to food security. However, due to the rapid population growth and increasing demand for food, this responsibility is becoming more and more challenging. The consequence of this challenge is the excessive exploitation of natural resources and destruction of the environment. This study aimed to investigate the cost structure, economies of scale, and inputs elasticities for the major farm crops of the Qorveh-Dehgolan Plain, in Kurdistan Province, through a translog cost function. The needed data were collected through a multi-stage cluster sampling survey in the 2017-2018 cropping year. The results showed that the average share of water input in the total production cost of the studied products was 12%. Results also showed that all ordinary own-price elasticities of demand for inputs were negative and smaller than one. However, the results of Allen-Uzawa's own price elasticities showed that demands for inputs could be elastic. Ordinary and Allen-Uzawa own price elasticity of water input were -0.76 and -6.7, respectively. The results also showed that wheat, tomato, barley, and alfalfa farms in the area under study were facing economies of scale, on average, while potato, cucumbers, and sugar-beet farms were facing diseconomies of scale.

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Bread is a basic and essential good that has a special importance in the consumer basket of households and constitutes the main food of many people in the world. The main objective of this study was to investigate the consumption behavior of household bread basket using demand systems during 1998-2018. Therefore, estimates of various demand systems including generalized ordinary demand, Almost Ideal Differential Demand, Rotterdam, Central Bureau of Statistics (CBS) and National Bureau of Research (NBR) were used to select the appropriate demand system to calculate the price and income elasticities of bread demand. Based on statistical tests and econometric criteria, the results showed that the generalized ordinary demand system was the most appropriate model for estimating the consumption demand of the bread basket in urban households. The income elasticities of all types of bread were positive, and, for urban consumers, Barbari and industrial bread were essential and Lavash, Sangak, and Taftoon were luxury types. Also, according to the negative expectations and cross elasticities of Sangak with Barbari, self-price elasticities of different types of bread were positive, meaning that Sangak was replaced by Barbari. In addition, the variable effect of subsidy targeting was positive for Taftoon and Lavash breads, negative for Barbari, and meaningless for Sangak. According to the study results, it is suggested that government officials pay special attention to the importance of bread consumption basket and preferences of its consumers in economic policies regarding food and household consumption basket (such as targeted subsidies).