فصلنامه اقتصاد کشاورزی
سال شانزدهم شماره 2 (تابستان 1401)

Optimal management and proper use of available water resources is an inevitable necessity. Therefore, this study was conducted to investigate the effect of irrigation water prices on its demand in the agricultural sub-sector of the country. For this purpose, to determine the price of water shade and its demand function in a different way from other studies and using the obtained coefficients in calculating the non-parametric random inclusive model, the data were determined and the price of irrigation water shade using coefficients obtained. It came from this model. The required data for the research were also collected from the website of the Ministry of Jihad Agriculture during the annual period of 2005-2016. The results showed that the average efficiency of irrigation water in the agricultural sub-sector during the study period was equal to 83.02%. Also, the results of estimating the irrigation water demand function showed that the irrigation water demand in the agricultural sub-sector is inelastic and 0.16 and the elasticity of water demand to technical efficiency is equal to 8.37. Based on the obtained demand function, the variables of water price, price of other production inputs and water efficiency have a significant effect on irrigation water demand in Iran's agricultural sector. Among the studied variables, technical efficiency, with the largest coefficient, is considered as the most effective factor in irrigation water demand. This result shows the need to pay more attention to the issue of water efficiency and efforts to improve and improve the efficiency of irrigation water in the agricultural sector. Also, according to the results, increasing the price of irrigation water in agriculture sub-sector will not have much effect on reducing demand and water consumption in this sub-sector and reducing irrigation water consumption in agriculture sub-sector will be possible by improving water technical efficiency.

The research aim is to study the yield including irrigated and dry-farmed wheat, barley, and corn in the climate and sub-climates of the country. So, the average yield of the studied products, average rainfall, and average temperature data have been used for the climatic change from the period 1982-2015. Due to the fact that cereal products over 56% and 77% of the cultivated area in arid and semi-arid regions, respectively. Therefore, in this study, only cereal are studied and among all of the crops, they have been selected, the five crops that have the highest area under cultivation. Finally, the function of various crops’ demands was used to investigate the effects of climate change on crops.The results show that the highest yield coefficients of rainfall are to precipitation in cold and sub-climates semi-arid cold, semi-arid hot, semi-arid temperate, cold dry, hot dry and temperate dry are related to dryland wheat, irrigated wheat, dryland wheat, dryland barley, dryland barley, dryland wheat, respectively. In addition, the highest coefficients of function of demands to temperature in cold and sub-climates of semi-arid cold, semi-arid warm, semi-arid temperate, cold dry, hot dry and temperate dry are related to dryland wheat, dryland barley, irrigated wheat and dryland barley, dryland wheat, respectively. According to the results of the research and in order to efficiently manage production and better performance, agricultural products in climates and sub-climates in the country are recommended. Compilation of a comprehensive cultivation model and allocation of the type of crop cultivation in the climate and sub-climate should be done by considering the reaction rate of the yield of the products and the exploitation of most of the mentioned products.

This research is aiming to investigate land use changing in Nowshahr County. Urban developing and shortage of land supplying and due to increasing in land demanding make several difficulties for sustainable developing for the city and different consequences for the environment too. This research with using game theory approach is going to evaluate rational behavior of each player in this matter of problem. Since different parties with conflicting interests make a social situation which each player choices will affect other player outcome, game theory would be a useful method to investigate this issues. In this research farmer and government are the two player who will make choices. This social situation proposed as a prisoner dilemma game and the result shows that game theory is reliable method for investigating this kind of problems. The results shows if government is going to prevent land use changing they should use encouragement policies for farmers, such as paying subsidies in addition to Legal barrier in otherwise farmers will have much powerful Motivation to changing land use. This research suggests Amount of 34155 million IRR per hectare in the form of various policies should be paid to farmers.

In recent years, fluctuations in the livestock products market have caused dissatisfaction among all groups in society.

The purpose of this study is to investigate the food security of different urban and rural income groups due to production, price and income shocks of livestock products in the form of a multi market equilibrium model. The required information was extracted from raw cost and income data of urban and rural households during the years 2008 to 2018 of the Statistics Center of Iran.

The results of the study showed that the food security of the community is more affected by the price shock of livestock products. Among the various urban and rural income groups, poor rural households will suffer the most from rising commodity prices. With a 30 percent increase in the price of livestock products, the average caloric intake of poor rural households will decrease by about 51 percent, which indicates that livestock products are not essential goods for poor households.

Eventually, the results show that the negative effects of rising livestock prices on food security will be somewhat mitigated by a 17% increase in household incomes assuming other food prices remain stable, but the worrying food security situation of poor rural households will remain strong. Therefore, to provide the calories needed by the most vulnerable sections of society to production and price shocks, the same nominal increase in the nominal income of this group of households in accordance with other sections of society is not enough and it is necessary to consider different scenarios of granting supportive food baskets and increasing income more including nominal than other household groups.

Given the rapid population growth of the present century, the issue of food has become one of the essential challenges. Based on this, the concept of food security in the world was introduced. The importance of this issue prompts all governments to adopt specific strategies and policies to meet this critical need and ensure food security and, ultimately, the national security of their country. In this regard, in the present study, the impact of economic and social factors of households and foreign exchange and trade policies on food security in Iran for 1396-1396, using the cost-income information of households from the Central Bank. To do this, first, the food security index (energy) for urban and rural households, then the free market foreign exchange rate gap index, and the trade liberalization index have been calculated. Then, the binary logit model will analyze the data to evaluate the influence of foreign exchange rate and trade policies on food security in the country. The results indicated that 71.4%, 67.9% have food security in urban and rural households, and 28.6%, 32.1% have food insecurity. The results also showed that foreign exchange policy has an adverse effect, and trade policy positively affects the food security of urban and rural households. Given the strong impact of foreign exchange rates and trade policies on the food security of urban and rural households, it seems necessary for the government to pay more attention to these policies to achieve food securities.

The purpose of this study is to investigate the effect of exchange rate fluctuations on agriculture trade balance of Iran. The required data were collected over 1998-2017 from the Iran's Central Bank, Customs, Statistics Center and the International Monetary Fund. GARCH family models were used to investigate real effective exchange rate fluctuations. ADF, PP, KPSS, GLS-DF unit root tests were applied. The results showed that the variables were stationary at the first order difference. The conditional mean equation was estimated for the ARCH effect was tested. The results indicated that the exchange rate variable had a non-ARCH effect, meaning that good and bad news of the same size had a different effect on the trade balance. Nonlinear ARCH models were applied to express the asymmetric effect on the trade balance. Based on the results of the EGARCH model was selected as a suitable model. The findings confirms that the effect of increasing and decreasing of the real effective exchange rate shock is (0.41) and (-0.87) respectively. In the following, the ARDL model for the relationship of Iran's trade balance with the eight major trading partner countries (including Germany, China, India, Turkey, Iraq, Afghanistan, South Korea and the United Arab Emirates) were utilized to examine short-term and long-term effects. The results of Band F statistics in ARDEL model indicates existence of a long-run equilibrium relationship between Iran's agricultural trade balance with Iran's GDP variables, GDP of Iran's major trading partners, real effective exchange rate and its fluctuations. This is consistent with theoretical foundations that the real effective exchange rate and GDP of the trading partner countries have positive and significant effects on Iran's agricultural trade balance. The results also showed that real effective exchange rate fluctuations had a significant negative effect on Agricultural trade balance in the long-run, but it did not have a significant effect in the short-run.