افشین امجدی

This study was conducted to investigate the effective components in the fluctuations of the total factor productivity of rainfed wheat production with emphasizing the role of climate change in the important provinces that produce rainfed wheat in Iran.

For this purpose, a True Random Parameter Stochastic Production Frontier (TRP-SPF) Model was estimated using panel data and the obtained coefficients were used for calculating the proposed productivity index .

The results of estimation of True Random Parameter Stochastic Production Frontier (TRP-SPF) Model show that the variables of seed, pesticides, labor force, cultivated area, technological progress, square of air temperature, effective rainfall and square of effective rainfall have a significant and positive effect on the production of rainfed wheat while the air temperature has a negative and significant effect on the production of rainfed wheat. The results of calculating CATFP index of rainfed wheat show the existence of fluctuations in it. The analysis of the contribution of factors affecting changing the CATFP index showed that this index is mainly influenced by technological changes and then climate changes. After that, scale efficiency and technical efficiency are in the third and fourth places of influencing the CATFP index.

Survey of the households demand is very important and necessary in planning for production of various goods and services in order to regulate the domestic consumption, import and export. Given the importance of this issue, the study of consumer behavior and their consumption pattern is a major part of economic research with the objectives of analyzing the consumption structure, identifying appropriate patterns for explaining the consumer behavior, predicting consumption and its changes. The main objective of the present study is to investigate the consumption and demand behavior of basic food items (cereals, livestock, poultry, fish and shrimp and its products, dairy products, oils, fats and butter, fruits, pulses, sugar and vegetables) in urban areas of Iran using pooled data and SURE method.

According to the objectives of this study, the best functional form of demand should be identified to explain the consumption behavior of urban households in Iran. Therefore, first the Generalized Ordinary Differential Demand System (GODDS) using the data of urban households (pooled data) was estimated using the seemingly unrelated regression (SURE) method and then, the appropriate functional form was selected. Then, according to the appropriate functional form, price and income elasticities were calculated by applying the conditions of adding up, homogeneity and symmetry for each of the equations of the demand system. Therefore, in order to choose and determine the appropriate functional form for food demand system, Generalized Ordinary Differential Demand System (GODDS) was estimated. The above model includes the Rotterdam demand system, differential form of AIDS, and the two hybrid models NBR and CBS. The selection of a suitable functional system is based on the constraints applied based on the θ1 and θ2 parameters. The system of demand equations was estimated using the seemingly unrelated regression (SURE) method. Also, in order to be consistent with the theory of utility, the constraints of adding up, symmetry and homogeneity were applied as linear equations. In order to investigate the impact of drought and also the targeted of subsidies, two dummy variables were included in the model. In other words, the first dummy variable was entered into the model to investigate the impact of drought in 2008. The second dummy variable was entered in order to investigate the effect of targeted subsidies in before and after 2010. In order to better understand household consumption pattern and cost situation and to analyze income, price and cross-demand elasticities, and the deciles were divided into three main groups. In other words, the average of the first three to the third decile was placed in the first group. Also, the average of the fourth, fifth, sixth and seventh decile in the second group and the mean of the eighth, ninth and tenth deciles were in the third group. Accordingly, in this study, the data used are pooled. The required data of research were gathered from the Statistics Center of Iran for the period 2006 to 2017.

Based on the results of the Wald test, the functional form of AIDS was selected against others. Price elasticity calculation results showed that own-price elasticity of food demand in urban areas is negative. Also, the highest own-price elasticity of food demand was related to fish and shrimp and its products (-1.03). The positive cross- price elasticity of food indicates that there is not necessarily a two-way substitutional relationship between food items and only in some cases (such as cereals and pulses), there is a substitutional relationship. Most positive cross-price elasticities have low values, indicating a poor substitution between food items. The calculation of income elasticity indicates the normality of commodity groups. The income elasticity of fish and shrimp and its products is greater than one that illustrates the luxury of this food.

Calculating the self-price elasticity of food in urban areas indicates the high elasticity of fish and shrimp and its products. Also, the income elasticity of fish and shrimp and its products has been more than one, which indicates the luxury of this food in urban areas. Therefore, pricing and subsidy policies should be set in such a way as to ensure a minimum consumption of animal protein for each individual in the community. Also, the policies governing the production and supply of the group (cereals, oils, fats and butter, fruits, vegetables, pulses and sugar) as well as the policies governing their consumption should be regulated in some way that the minimum supply of foods is to be possible for households.

The separability of consumer desires is a necessary and sufficient condition for multi-stage budgeting and Collectivization is consistent of commodity where costs are allocated between edible groups using price indices and intergroup allocations are made independently of other groups. Given the high share of meat types (23 percent of household food and beverage expenditure) in the household budget and the important nutritional role of meat in people's health, in this study, to determine the consumption pattern of meat products in Iran used to Rotterdam demand function. In empirical studies of demand, the concept of separation is used to correctly estimate demand function and limit the number of parameters. For this purpose, data related to price index and cost of meat types (livestock, birds, fish) central Bank over the years 1995-2016 were used. The results of the separability tests support the hypothesis that consumers first divide their income between 13 meat products in three groups (livestock, birds, fish) assigns and then approves the allocation action between the types of meat subgroups that are grouped. Also results of system estimation showed that the groups had a negative intrinsic price elasticity.In the meantime, the price elasticity of groups livestock meat, birds and fish meat are respectively equal to -0.89, -0.59 and -0.77. The basic suggestion of the present study is that prior to any action on the demand system approach there should be weak separability tests.

This study aimed generally at investigating and analyzing the consumption basket of rural households in different income deciles to achieve food security. For this purpose, the income deciles were initially divided into three general groups including the average of the first to third deciles as the first group, of the fourth to seventh deciles as the second group, and of the eighth to tenth deciles as the third group. Then, the Generalized Ordinary Differential Demand System (GODDS) was estimated using the integrated data of 2006-2017 in Seemingly Unrelated Regression Equations (SURE) method; and using Wald test, Almost Ideal Demand System (AIDS) function was selected as the appropriate functional form. The results of the price elasticity calculation showed that the price elasticity of food demand in rural areas was negative. It was also found that cereals and livestock meat as well as livestock and dairy products and sugar were complementary goods; cereals were known as the complementary goods for livestock, dairy products, and sugar; in addition, vegetables and pulses could be considered as substitutes for cereals in the rural areas. The calculation of income elasticity showed the positive values for food groups in the rural areas, indicating the normality of commodity groups. According to the results, the income elasticity of cereals, livestock, fish meat, shrimp and its products, dairy products, pulses and sugar was obtained a figure more than one, indicating that these foods were considered as the luxury goods.

Fluctuations in the agricultural products price face producer and consumer with risk and uncertainty. Futures contract as an important tool of hedging pays to price risk management. Base on, this study has tried to use of the least mean-variance method investigating agricultural product hedging situation in the Wall Street exchange market at the one-month period of December 2014. The results show that the futures contract of corn decreasing risk price about 26 percent. Also, in comparison with corn, the futures contract of soybean has more hedging than corn futures contract. The results of hedging efficiency of wheat futures contract represent hedging is up to 83 percent and this amount for cotton is about 79 percent. According to the results, development of agricultural commodity exchange specially the agricultural futures contracts can be minimized farmers concerns in the field of risk.

According to amount of oil seeds import in Iran are more than 80% of domestic needs، in this study، import comparative advantage in soybeans using RCA and RSCA index is calculated in 1961-2008 periods for Iran and ten important importer countries. Iran’s Competition state is investigated. Also long run relation between production and import comparative advantage index is estimated using Johansen test and Vector Error Correction Model (VECM). Results show that Iran has import comparative advantage in soybean import، but shock effects on amount of this index، adjusted in more time than others. Therefore، exporter countries will have less willingness for export to Iran. In this aspect، importance of domestic production’s increase for domestic needs will be imperative. Also results showed that with increasing domestic production in long run، amount of Iran’s import comparative advantage will be decreased and therefore with decreasing import to country، less exchange will be out of our country.

The purpose of this study is determining the economic efficiency of agricultural production cooperatives and factors affecting it and their profits. The data were collected using multiple random sampling methods. The estimation results of profit function in Fasa, Firouzabad, Marvdasht and Eghleed cooperatives showed that amount of primary and existing capital and cost of total activities of agricultural production cooperatives have direct relationships with their corresponding frontier profit. As the results of economical efficiency distribution of these agricultural production cooperatives showed that average of economical efficiency score is 0.71 with a relatively high range (between efficient and inefficient of agricultural production cooperatives). Therefore there is a possibility to raise their profits through transferring managerial factors of high efficiency agricultural production cooperatives to those with low efficiency. As the results showed that managing director level of education, number of activities of agricultural production cooperatives (activities diversity), distance of agricultural production cooperatives from downtown and agricultural production cooperatives located in Firouzabad relative to other mentioned agricultural production cooperatives had direct relationship with economical efficiency of agricultural production cooperatives and the kind of governmental management of agricultural production cooperatives relative to independent management and activity period of agricultural production cooperatives and the agricultural production cooperative located in Fasa city relative to Eghleed and Marvdasht and the agricultural production cooperatives located in Eghleed city relative to Marvdasht city had indirect relationship with economical efficiency of agricultural production cooperatives in Fars province.

Despite the importance of machinery in agriculture, (Iranian) government policies have not led to appropriate supply of machineries toward agricultural sector in recent years. Machinery canalization to this sector not only has not provided the mechanization of agricultural sector but also it has not been able to compensate depreciation of machineries during recent years. Therefore, this condition has caused the reduction of mechanization level and has decreased the mechanization multiplier and also forced farmers to use obsolete machines. In this paper, the agricultural mechanization in Iran has been reviewed by using last 15-year data on agricultural machinery and mechanization and interviewing the experts. The research results show that machinery procurement, in terms of number and type, during 1st, 2nd and 3rd economic development plans has not been in accordance with plan forecasts. Agricultural machinery's price has increased more than guaranteed prices of agricultural products and also loan ratios to machinery prices have been decreasing repeatedly. In spite of what is mentioned above, agricultural mechanization has been improved, showing current mechanization role in agriculture sector. Finally, this paper discusses bottlenecks of agricultural mechanization in Iran.