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.

The separability of consumer desires is a necessary 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 independent of other groups. 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 selected commodities (citrus fruits, cucurbits, and vegetables) derived from the Central Bank over 2016 in urban households of Iran were used. The results of the separability tests support the hypothesis that consumers first allocate their income to selected commodities in three groups (citrus fruits, cucurbits, and vegetables) and then approves the income allocation action between the types of its subgroups that are grouped. Also, the results of the system estimation showed that all groups had a negative intrinsic price elasticity. In the meantime, the price elasticity of the groups of citrus fruits (orange, tangerines, and lemon), cucurbits fruits (potato, tomato, and onion) and vegetables (the leafy ones) are equal to -0.83, -0.48 and -0.91, respectively. Given the income elasticity calculated for the three commodity groups, the second commodity group (potato, tomato, and onion) is more essential than the other commodity groups, which should be considered in government policies as to agricultural production and pricing.

In this study, the index of producer supports was investigated among the development programs in period 1989-2011. Then self-sufficiency index in chicken meat during this period was calculated and its properties were evaluated. In this study the main challenge is whether the producers’ support in Iran will lead to improvements in production and self-sufficiency coefficients or not. For this purpose the variables stationary was investigated for estimating self-sufficiency model and after determining the optimal lag of self-sufficiency and Producer Support Estimate (PSE), then Granger causality test and finally the VAR model were estimated. The results showed that changes in the level of self-sufficiency index of chicken meat in the short term in each period is dependent on the support of the producers of chicken meat in the previous period. The estimated coefficient of PSE showed that in short term, PSE index of chicken meat producers has not been a suitable efficiency in changes of self-sufficiency index. The results of impulse response function showed that the effects of shocks to self-sufficiency index due to changes support policies in different periods is varied and this effect will be adjusted after seven periods.

In fifth development plan, some suitable scientific and managerial policies have been expressed in order to optimizing the use of inputs and producing compatible crops with the conditions of each area. In this study with applying positive mathematical programming method, we evaluated the impacts of possible changes in consumption of inputs on cropping pattern of agricultural crops in Amol Township. These possible changes are propounded in the form of some scenarios like 1% reduction in water usage (PMP1), 7% reduction in fertilizers usage (PMP2), 1% reduction in pesticides usage (PMP3), 0.64% increase in employment (PMP4) and simultaneously mix these scenarios (PMP5). So that in 1392-1393, 124 farmers of this Township were interviewed through simple random sampling method. The results show that with running scenarios 1, 3 & 4 separately, any changes don’t occur in cultivated area of crops; so the least reduction that models reaction to it was calculated by sensitivity analysis. Also the results show that with running scenario 5 (PMP5), observe respectively 5 and 0.2 percent decrease in cultivated area of crops and current gross margin of this Township in compare with current model. So that the greatest reduction in cultivated area, respectively with 40 and 30 percent are related to irrigated barley and Rainfed soybean. Also, all of these scenarios lead to reduction in gross margin, which will reduce the welfare of the farmers in this area; therefore, it is suggested to take the necessary actions for improving their livelihoods.

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.

This study investigates price transmission in citrus market and in different levels as producer, wholesaler and retailer using Error Correction Method (ECM). For this purpose monthly data was used. According to monthly data, first seasonal unit root was investigated. Based on their observations in the seasonal adjustment process, the transmission pattern of the domestic market price for the desired products was estimated. The results of estimation of price transmission model show asymmetric transmission in citrus market and in different levels. Only in orange market there is symmetric price transmission in long run between levels of wholesaler –producer. Also, in tangerine market there is symmetric price transmission in short run between levels of wholesaler – retailer and in wholesaler –producer. According to this results, market size and speed of price transmission in different levels of citrus market was different. Based on the importance of price transmission and its relation with market efficiency, it is suggested that control and market regulation policies with the aim of establishing symmetric structure in market are made.

Understanding of government policies and categorizing and prioritizing them in order to perform accurate them is essential. Hence, in order to achieve optimal production conditions should take suitable supporting policies for agriculture sector. This study is to assess sector consumer supporting policy of livestock and poultry sub-sector during the first to fourth program during 1989-2009 by MPS and CSE indices by using of OECD approach. The results show that for livestock and poultry sub-sector, CSE in nominal value change form -163.06 Bil Rials in 1999 to -78998.43 Bil Rials in 2009. Also, in real value change form -3197.41 Bil Rials in 1999 to -39179.9 Bil Rials in 2009 (about 12 times). Most supporting is allocated during 2end development program to livestock and poultry sub-sector that is 10223.05 Bil Rials. Results of demand model shows that livestock and poultry consumer supporting policy have had a variety effect on demand. So, consumer supporting policy has negative effect on beef and lamb (-0.13 and -0.08). But due to consumer supporting policy, chicken and specially milk demand, have increased (0.25 and 0.43). It seems that according to quantity and direction of consumer supporting policy effect on demand, we could use it for determination of suitable direction of consumer supporting policy.

The agricultural sector in Iran has good potential for foreign currency income. But to enter the arena of international trade, requires having the necessary qualifications to join the World Trade Organization (WTO). This study is surveying competitive advantage of main agricultural products of Fars province using a variety of indicators. In this study, Domestic Resources Cost (DRC), Social Cost-Benefit (SCB) and Net Social Profit (NSP) for the major crops that have the largest area under cultivation using Policy Analysis Matrix (PAM) were estimated. In this study, In addition to the dollar exchange rate, the results based on euro and equilibrium exchange rates are determined and sensitivity analysis was performed. The results show that respectively, irrigated cucumber, irrigated tomatoes and irrigated corn have the greatest comparative advantage in the production. The irrigated wheat, rainfed wheat, irrigated barley, rainfed barley, irrigated red beans, rainfed lentils and irrigated cotton have not competitive advantage in the three exchange rates. The results of the sensitivity analysis show that this changing has not any effect on ranking and comparative advantage of products dramatically.

The big Sefidrud basin supplies the irrigation water of the Guilan fertile plain and provides requested water for strategic crop of rice in mentioned province. Water resource development projects in upstream of mentioned basin، risks supplying guaranteed irrigation water for Guilan plain. Present study investigates the effects of ten Sefidrud network inflow reduction scenarios under eight irrigation network conditions using regional mathematical programming based on positive mathematical programming and considering hydrological situations in central valley irrigation district of Guilan province. Requested data sets were obtained from Iran''s water resource management company، Guilan Water Company and different consultants'' researches. Acreages removed from irrigation module، avoided loss because of applying irrigation efficiency improvement projects and reduced gross margins of cultivation incentral valley irrigation district under different inflow reduction scenarios and network condition are the most important results of this study. Results revealed that nine percent reduction of the Sefidrud irrigation and drainage network inflow in central valley under current network condition caused 7. 6 percent of rice acreages and 7. 9 percent of total crops acreages to remove from irrigation module. Simulations based on changes in network condition showed the considerable effect of irrigation efficiency improvement policy on avoiding loss due to inflow reduction. Mentioned results provide a base for cost-benefit analysis of irrigation efficiency improvement projects in this irrigation district.

Iran is known as one of the most important date producing and exporting countries. Given the importance of Iran’s date export and its share of about 14 percent in agricultural exports of the country، this study investigates the comparative advantage of Iran''s date export against its large global rivals as well as the long term relation between export advantages of the country and the amounts of production in this country and its competing countries، drawing on Johansen test and Vector Error Correction Estimated (VECM) for the 1996-2008 period. The study result show that shock effects on export comparative advantage is adjusted in almost 1. 5 periods، which is shorter than the time periods required for the other countries. As shown by the results، although the Iran’s export advantage has increased following an increase in the country''s domestic production in the long run، it was Tunisia which has the highest amount of comparative advantage and also the highest relation between production and export comparative advantage. While Iran has the fifth rated. Iraq، Algeria and United States are the other competitors that have achieved further adjustment between the date production and export comparative advantage، compared with that of Iran. Therefore، given the increase in production can be created in a better long-term export advantage in global markets، attention should be given to the more adaption of Iran’s date domestic production and export advantage against big competitors and specifically Tunisia.

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 general objective of this paper is to recognize factors affecting the target market of Iran's pistachio and date export. For this purpose, the target market of pistachio and date export(with use screening method), effective factors on export demand of pistachioand date, and elasticity coefficient of export demand of pistachio and date were all analyzed during 1971-2007. According to the results, Non-Asian countries with highincome are suitable markets for exporting Iranian date. Also, Asian and Non-Asian countries with high income are suitable markets for exporting pistachio of Iran in long run. Increasing the date price must be stopped to assist promotion of hygienic level and packing export date. Increasing pistachio price with regard to the appearance of newexporters is hazardous. Generally, according to findings, suitable markets for exporting Iranian date are proposed France, United Kingdom, Germany, Morocco, United State of America, Italy, Spain, Canada, Russia, Georgia, Switzerland, Netherlands, Australia andBelgium, and suitable markets for exporting Iranian pistachio in long run are Luxemburg, Hong Kong, Germany, Spain, Italy, Netherlands, France, Russia, Jordan, India, Syria, Slovakia, Palestine, United Kingdom, Cyprus, Ukraine, Slovenia, Belgium, Latvia and Armeniarespectively.

The main purpose of this study is to investigate impacts of monetary policy on macroeconomic variables and fluctuations with methods such as Rational Expectation (Azam theory), Pesaran and Shin and Hendry during 1973-2006.The results show that analyzing the impacts of real effective exchange rate(reer) and inflation rate(inf) in rational expectation framework isn’t possible. Both central bank policy tools have great impact on reer and inf (long run & short run). So choosing a good and suitable policy is very important for macroeconomic stability.

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.