مجله اقتصاد و توسعه کشاورزی
سال سی و دوم شماره 3 (پیاپی 40، پاییز 1397)

Globalization is an inevitable process that one of its consequences is the liberalization of trade and the reduction of protectionism. Trade liberalization causing the heavily interdependent economics of the countries around the world to reduce customs and trade barriers to a minimum level, and make financial transfers between countries easily done. Rice is the most important and strategic crop after wheat and plays a significant role in trade and food security of the world and Iran. Because it provides more than 20% of human total daily calories and Almost two thirds of the world's population depends on rice for food. The total Production of Rice in Iran during 2012-2013 was about 2.3 million ton and about 93% of rice products are yielded in Gilan, Mazandaran, Khuzestan, Golestan and Fars provinces. About 88% of total production of rice in Iran is allocated to domestic consumption while just 12% of goes to the world market. Total consumption of rice in Iran is about 3.2 million ton.   The model that is used in this study is Agricultural sector partial equilibrium model with endogenous prices. The data used in present study are the average of production, consumption, export, import and area under cultivation quantity, which export and import prices for long, medium and short grain rice and import tariffs for two growing years of 2011-12 and 2012-13 are considered. These information are provided from agriculture jihad organization of Iran, Customs Office of the Islamic Republic of Iran and the book of export-import regulations. In current research, at first simple linear demand function is calibrated for long, medium and short grain rice based on demand price elasticity. The supply function involves two parts: domestic supply function and export supply function. The calibration of domestic supply is done by a Maximum Entropy integrated PMP method and calibration of export supply function is based on export supply price elasticity. It should be noted that the demand elasticities used in current study are captured from various studies and the export supply elasticities are taken as unity following Aydın et al (2004). Constraints that are used in the model are comprised of the constraints of area under cultivations, water, chemical fertilizer, variable costs, constraint of commodity balance and constraints of calibration includes area under cultivation and export.   The investigated scenarios are the reduction of import tariffs for rice by 10, 25, 50, 75, 90 and 100 percent. The results of present study showed that The area under cultivation of long and medium grain rice, compared to the base year (2012 and 2013 will decrease about 0.61 and 3.38 percent), in Mazandaran province, about 0.49 and 9.18 percent in Gilan province, about 2.82 and 4.32 percent in Golestan province , about 90 and 0.6 percent in Khuzestan province and about 24.47 and 2.47 in Fars province t. Short grain rice in Golestan province will decrease about 22.93 percent and in Fars province will decrease about 43.33 percent. Generally, with decreasing tariff rates, the long, medium and short grain rice, compared to the base year (2012 and 2013), will decrease about 21.5, 4 and 11.5 percent, respectively. Also, the consumption of long, medium and short grain rice will increase by 0.5, 1.1 and 0.7 percent, respectively. The average import of long, medium and short grain rice will increase by 5, 11 and 33.5 percent, respectively and Exports of long, medium and short grain rice also will increase by about 7.7%, 11.7% and 11.43% as a result of tariff cuts. Also, the net social welfare due to the reduction of rice tariff rates relative to the base year, will increase about 0.2 percent. The average welfare of consumers will increase about 1% and the welfare of producers will decrease about 1.7 percent compared to the base year. Also the welfare of the state will increase about 9.5 percent compared to the base year.   Considering small cultivated pieces of land, the high cost of production, the lack of relative advantage in the production of some types of rice and also the high waste of factories in the country, trade liberalization can be fruitful. Considering the importance of product advantages in producing, exporting and importing as well the best quality of Iranian rice, creating new technologies and new planting methods such as hydroponic cultivation, which leads to increased performance and increased water productivity per unit area, and also planting kinds of rice which have advantages in each province would conclude increasing the welfare of rice producers.

over the previous years, with development and expansion of broiler breeding units and its increasing production, chicken meat has become an essential commodity in the household food basket and has been attributed as one of the most important sources of protein supply for households. Recently, the chicken market pricing as well as exchange rate volatility has become one of the issues in that industry. One of the main sources of this risk in the chicken market is the exchange rate volatility, which affects the imported inputs markets.   The current analysis is based on 21 years of monthly data on exchange rate, chicken price, corn price, soybean meal price and fish powder price over the period 1995-2016 obtained from the Central Bank of the Islamic Republic of IRAN and Livestock Support Company of Iran. In present study, the risk of overflow between the exchange market and the chicken market and its major import inflows are examined. Estimation has been carried out using GARCH-type models, based on the multi variation GARCH (MV-GARCH), for both the extreme downside and upside Value-at-Risks (VaR) of exchange rate volatility risk and chicken market and its major inputs markets. It depicts market risk by means of the probability distribution of a random variable and evaluates the risk with a single real number. While the VaR method is used to measure extreme market risk, as the risk interaction and spillover effect among different markets is apparent. Furthermore, according to a new concept of Granger causality in risk, a kernel-based test is proposed to detect extreme risk spillover effect between two mentioned markets. The methodology used is Granger causality in risk provided by Hong (2001) and Hong et al. (2003). It requires that the time-varying VaR to be evaluated for each return, and then it should be determined if the historical information about risk in one market increases one's ability to forecast its occurrence in another market in terms of Granger causality concept.   According to the results of the Dickey-Fuller unit root test, all variables are stationary at first difference, and based on the results of the seasonal unit root test, seasonal behavior pattern in variables has been found. Then volatility clustering was confirmed by testing heterogeneity of conditional variance. Since the results showed cluster fluctuations in the variables, we evaluated the MGARCH and TGARCH models and then we used VaR to estimate the value series at risk for all variables. The result of VaR section showed that the upside risk of chicken and Fish powder is the highest, and soybean meal and exchange rate having the least risk. In the downside risk chicken and fish powder were known as the most risky markets, corn and exchange rate as least risky. But it is fascinating about the exchange rate that it has a higher upside risk than the downside risk. In other words, there is a greater risk for an increase in the exchange rate market. Finally, the relationship between risks of markets was investigated using risk granger causation. The results indicated that there are over and over additional risks for traders in all of these markets and there is a significant risk spillover between the exchange market and the chicken market and its major inputs markets, the severity of upside spillover is higher than the falling price of the exchange rate. There is a significant risk spillover between the chicken market and its major inputs market at the 95% and 99% confidence levels and in all interruptions, there is a spillover of upside and downside risk.   The exchange rate as a key variable, influences many of the government's policies and economic decisions. Any volatility in the exchange rate will have an adverse impact on both micro and macro levels. Given its impact on the imported input market, it is recommended that a coherent program of foreign exchange market management and stabilization to be developed by the central bank and the government. taking into account the high impression of the input market from volatility and exchange rate risk, it is suggested that, as far as the principle of comparative advantage allows, more strategic inputs such as corn and soybeans to be produced. Considering impressionability of Chicken markets from its inputs market in order to provide consumer welfare and prevent the imposition of additional costs, it is recommended a duplicate effort to be made to implement the policies of market regulation of inputs and reduce volatility in these markets.

One of the challenges faced by governments in the last century is environmental crisis such as greenhouse gasses. Due to population growth in the world, human activities including agriculture and dairy cattle industry for providing food security for peoples have increased and caused the more pollution and greenhouse gasses emission. to the extent that the amount of greenhouse gasses released by agriculture and dairy cattle's activities in the world is more than greenhouse gasses produced by transportation activities. The main agricultural greenhouse gases (GHG) are methane and nitrous oxide. Methane is produced in the rumen of the cows by methanogen microbes and are naturally present in all ruminant animals. Most methane is emitted when cattle burp. Nitrous Oxide is emitted from soil when urine, faeces and fertilizers broken down by microbes in the soil. Governments and policy makers, by applying policies and programs are struggling to overcome the problems encountered in the environmental field and reduce the negative and harmful effects of human functions on the environment. One of the ways to control and reduce environmental damages such as greenhouse gasses is using economic tools and policies such as taxes on environmental degradation activities.   This study aimed to evaluate the appropriate green tax rate on methane emissions in dairy cattle industry in Hamedan province. Therefore, of 44 dairy farms in Hamedan province were chosen by simple sampling method and data were collected about the cost of producing this section through questionnaires during 1395-96. By calculating the share of costs using shephard lemma and the Iterative Seemingly Unrelated Regressions method (ISUR), the cost function and cost sharing equations were estimated as a system. The advantage of the current model is that the ISUR estimators utilize the information present in the error correlation of the cross regressions (or equations) and consequently are more efficient than single equation estimation methods such as ordinary least squares. In the selected model the price of animal feed (Pfood(, price of medicine and vaccination )Pmedicin (, price of energy(Pene( and labor wage (Pwag(, are the independent variables.   The results indicated that about 52% of the pattern coefficients were significant. Thus using Translog cost function is appropriate for estimating the cost function in dairy cattle units. The calculated R2 criterion for Translog cost function is estimated about 0.99 in this research, which implies that about 99 percent of the variations of milk’s total cost are defined by the variables including animal feed price, labor wage, energy price and the price of medicine and vaccination. Parameters for the input share equations including animal feed price, labor wage, energy price and the price of medicine and vaccination, are calculated respectively as 0.53, 0.36, 0.64, 0.57 and 0.34 for the income share equation. The adjusted coefficient of determination, () for the Translog cost function, is about 0.98, and parameters for the input share equations including animal feed price, labor wage, energy price and the price of medicine and vaccination is respectively 0.47, 0.28, 0.47, 0.36 and 0.22 for the income share equation. Based on the results, the D.W of the equation is 1.98, that indicates the fitted regression is true and there is no autoregressions between residuals and independent variables.   Based on this study results, the appropriate green tax rate for methane emissions in the dairy cattle industry is 1.1% per kilogram of milk production. The results revealed a negative relationship among green tax rate and pollution emissions coefficient and marginal cost of production. Also, a positive relationship between green tax rate and the output price has been detected. This signifies that by increasing green tax rate, the emission of pollutions by dairy cattles is reduced. So putting emphasize on the application of green taxes in order to reduce emissions of methane greenhouse gas. It is also recommended that relevant organizations such as the country's environmental organization, by examining the prevalent infrastructure in the country and providing conditions, use green taxes as an economic tool for controlling and reducing environmental pollution. Moreover, in the feasibility studies and the pre-construction of the generating unit, the green tax should be considered in the evaluations.

Economic theories and empirical results show that the economic performance and the resulting social welfare are influenced by the market mechanism, and the gap of the market structure from the competitive market implies the failure of the market and in this situation allocation of resources will be inefficient. In other words, there is a causal relationship between the existence of market power and the lost prosperity of the economy. Thus, the market structure affects market incentives and decision making process on market outcomes. Also, the analysis of the situation of market competition can affect the process of adopting supportive policies and its results. In market structure studies, economists have traditionally defined industry horizontally i.e. by including firms that make similar products. While non-competitive behavior in the market is not necessarily related to horizontal behavior and the horizontal structure only represents just a part of the market power. In fact what is known as market power is the result of combination of the vertical and horizontal competition in different levels of the markets.
Milk is one of the agricultural products that more than 70 percent of it goes into the processing industry. The average per capita consumption of milk in Iran is about 90 kg, while the average global consumption is 156 kg and in the European countries is 300 kg. Also, the statistics of dairy factories collected by the Statistical Center of Iran show that between 2004 and 2011 more than 65% of the total amount of raw milk was absorbed by less than 10% of dairy factories. This is a sign of the high concentration of this industry. Meanwhile, the industry is facing a large number of dairy consumers to sell its products with their average per capita consumption in the country much lower than that recommended by the World Health Organization. However, increasing concentration in this industry can affect the bargaining power of the processors and the formation of the price of dairy products. Therefore, the purpose of this study is evaluation of the horizontal and vertical market structure in dairy products market including pasteurized milk, yogurt and cheese.   In order to investigate the vertical structure of the market, based on the formation of the price of dairy products, a bilateral monopoly bargaining pattern with axiomatic approach was used. In estimation of the bargaining model we applied EM algorithm to overcome the hidden supply reservation price. The horizontal structure of the market was also evaluated using the Lerner index. Its needed to be explained that the statistics and information required for this study including the production of dairy products, pasteurized milk, yogurt and cheese, the amount and value of consumable inputs including labor, raw milk, milk powder, inventory of capital goods, cost of depreciation, The cost of maintenance and packaging costs for a number of dairy enterprises were collected from the Iranian Statistics Center during the period 1990-2012.   the results of this study showed that the horizontal structure of the market for these three products was far from competitive and Producers are able to raise the price of these products above the marginal cost. However, the value of Lerner index in the study period has been decreasing with many fluctuations and this meant improving the competition in the studied years. Also, the results of the bargaining model demonstrated that the bargaining power of processors in pricing these products are more than consumers. Somehow, in average about 70% of dairy trade gains owned by processors and 30% of that is the consumers' share. In all three products, in addition to the price of raw milk, the price of capital input and packaging play a significant role in the agreed price change of dairy products, especially pasteurized milk. So one percent reduction in the price of capital input with current conditions, leads to a decrease in prices of milk, cheese and yoghurt by 0.33, 0.13 and 0.15 percent, respectively.   The results indicate that 70 percent of the welfare loss of the manufacturer is passed on to the consumer as a result of higher costs while only 30 percent increase in welfare as a result of cost reduction Will be given to consumers. As a result, the negotiations on the price formation of these products have been in a way that the government has diverted from its basic goal. The reason for this would be the coincidence of the duties of the government organization responsible for pricing law, consumer protection and producer protection. Therefore, it is necessary to examine the formation of independent governmental or non-governmental organizations in support of consumers and to study the appropriate ways to operate existing laws in order to support consumers.

Qaleh Chay dam basin is one of the largest irrigation regions for food production in Ajabshir and household livelihood mostly depends on agriculture but the occurrence of drought periods and extraction of underground water has led to a reduction in surface water and underground aquifers. Continuing this process will reduce the agricultural production and consequently the region will encounter economic crisis. On the other hand, the uncertainties of various factors such as rainfall and temperature, which are not easily quantified, would affect agricultural resource system. in current study in order to response to mentioned crisis and uncertainties, interval two-stage stochastic programming (ITSP) has been proposed for water allocation of Ajbashir Qaleh chay dam among agricultural products and the results have been compared with extended ITSP.   Interval two-stage stochastic programming (ITSP) is an effective alternative to deal with uncertainties and it can be formulated as follows:  The data for the selected products (wheat, barley, potato, onion, grape, walnut, almond and apple) were collected from Regional Water Authority and Agriculture Jihad Organization of East Azarbaijan in 2015-16, and in some cases, completed by a questionnaire. The model was written in the GAMS package. Results of ITSP showed that under the low flow level, the total amount of water allocated to all crops would be zero with the exception of almonds where the final allocation of water for it would be [3.64, 20.61]. therefor,Under the medium flow level, the allocation of water for potato, onions, walnuts, almonds and apples would be[0, 5.49], [0, 28.57], [1.30, 35.71], 31.43 and 20 ×1000 m3 respectively and it would be zero for others. Finally under high flow level there would be no water shortage for all products. Water shortages may occur when the seasonal water flows do not be adequate for the promised water allocation for each crop. In such cases users will have to utilize supplementary resources. The results of extended ITSP showed that for wheat, barley, onion, grape and almond the third alternative under low level and the first one under medium flow level can be used. For potato and apple under low level the first alternative and under medium flow level the third one can be applied. Both the first and the third alternative could be utilized for walnut if the flow level was low. Finally, comparing the value of the objective function of ITSP and extended ITSP showed that with the utilization of supplementary resources for satisfying the water needs, the net profit of the system decreases slightly.   In this paper, ITSP method was used to allocate water to agriculture products. The results showed that there was water scarcity for products on drought and normal years. Users can utilize supplementary resources to cope with water scarcity. An extended ITSP method is based on retrieving water shortage and its results revealed that the system net benefit decreases as supplementary water reservoirs were used for water shortages. Based on the results obtained, highlighting the irrigation efficiency is recommended.

Weather factors such as temperature has an enormous influence on agriculture. Therefore, efficient weather risk management has become an urgent requirement for this sector. In recent years, a new instrument named weather derivatives has been introduced to cope with production risk. So, this paper aims at designing and pricing the temperature-based weather derivatives (WD) in order to reduce risk exposure for Iranian agriculture industry. For this purpose, a put option with cumulated growing degree days (GDD) as its underlying index has been selected   We first examine the relationship behavior of temperature and yield for wheat and Rice in Shiraz. Then, for designing and pricing WD in agriculture, GDD index has been selected as one of the most widely used temperature indicators in agricultural sector. We design this contract for each stage of wheat and rice life cycles instead of designing one contract for crop’s growing seasons. So, the life cycles of two crops (Wheat and Rice) divided into 7 stages titled: Emergence, Tillering, and stem elongation, Gravidity, Flowering, Milky ripe and Maturity. Since contract design happens during these stages, we have 6 contracts for each product. Each contract starts with the beginning of one stage and continues until the other stagestarts.
The GDD index is calculated based on the temperature data and the life cycles of the wheat and rice in Shiraz. So, the long-term mean of GDD is calculated as the Strike level of put option contract. The simulation method based on daily temperature data is used for pricing the contracts. Finally, the expected payoff and the price of the options are determined using the Monte Carlo simulation method.   The results revealed a significantly positive relationship between wheat yield and GDD as well as a positive impact of GDD on Rice yield. This implies that increasing growing degree days would increase wheat and rice yield. The R2 coefficient also indicates that 76 percent of the variations in yield of wheat and rice are explained by the growing degree day's index. Therefore, the design of temperature based weather derivatives contracts will have high efficiency in order to cover the risk of farmers.
As expected, rice has a relatively higher strike price than wheat as rice-groups accumulate GDD in warm seasons. We assume that the annual risk-free interest rate r is 15 percent and the expected payoff also the price of the contract put option is calculated based on 10000 Monte Carlo simulations. Based on the results, the most wheat payoff in Shiraz was related to the second contract (from the November 21st to the March 6st). Therefore, the use of the temperature option in this period will compensate farmers for their loss. In terms of rice, the most payoffs in Shiraz have occurred in the twelfth contract (Aug 19st to Oct 17st).   Financial weather derivatives (WD) are designed to serve as hedging instruments against weather risk and to balance the income of producers such as farmers. WD was first traded in 1997 and since then their popularity has increased. However, weather derivatives as well as designing and pricing of contracts based on weather has not been introduced in Iran. Therefore, in present research, while introducing the mechanism of the weather derivatives and options based on weather indicators the designing and pricing of put option contracts based on temperature have been discussed in Shiraz. For this purpose, GDD index has been selected as one of the most widely used temperature indicators in agricultural sector. The GDD index is calculated based on the temperature data and the life cycles of the wheat and rice in Shiraz. So, the long-term mean of GDD is calculated as the Strike level of put option contract. The simulation method based on daily temperature data is used for pricing the contracts. Finally, the expected payoff and the price of the options are determined using the Monte Carlo simulation method. As discussed before, the temperature options for each city and product are designed based on the different stages of life cycles of the crops so we plan and set the price of put options for six different time periods. Based on the results, the most wheat payoff in Shiraz was related to the second contract during the November 21st to the March 6st. Therefore, the utilization of the temperature option in this period will compensate farmers for their loss. In the case of rice, the most payoffs in Shiraz have occurred in the twelfth contract (Aug 19st to Oct 17st). Therefore, it is recommended to use the results of the present study to launch a weather derivative’s market. In addition, it is vital to change and revise these contracts by conducting various studies about the effects of changing contracts specifications on farmers and other Contributors in the market.

Over the last two decades, awareness of resilience and sustainability and also efforts to reduce unsustainable production patterns have significantly increased. Hence, it is crucial to examine the resilience and sustainability of production systems. Resilience explains how well production systems withstand and/or rebound from aberration. Sustainability concept based on Commission’s words is: “development that meets the needs of the present without compromising the ability of future generations to meet their own needs”. The important issue relevant to resilience and sustainability and the resilience of farms/agricultural systems is, whether resilience or sustainability can be considered as a property of a system or needs to be understood as a process. Since both of them are not essentially opposed but have various theoretical and methodological implications, it is necessary to define a resilience and sustainability indicator. So, it is required to have an intelligent objective function for fairly balancing between production systems and dimensions of sustainable production to fulfill economic benefit and the resulting environmental benefit, etc. Based on the existing published literature, studies focusing on both resilience and sustainability indicators in industrial dairy farms by using multi-objective non-linear programming and swarm intelligence algorithm have not been carried out. Therefore, it is the aim of the present study to design the “automata resilience and sustainability indicator” for industrial dairy farms. The objective function has a hierarchical structure and in order to integrate these pillars into a single score, a value between zero and one, Analytic Hierarchy Process (AHP) has been used that the value of one means complete sustainability.
Material and The objective function should be maximized which has 5 main indicators including, environmental, economic, social, technological and political issues. Each indicator has some sub-indicators. So, we designed and modeled formulas for all of them. The value of objective function is normalized, therefore, its maximum possible value is "one", which indicates the complete resilience and sustainability of dairy farms. The resilience and sustainability indicator is obtained at three levels. Eight types of constraint sets are considered. Then, the model has been implemented using data of 30[1] industrial dairy farms in Khorasan-Razavi province of Iran during 2016.   The resilience and sustainability indicator across all farms was obtained 0.43 and which was low. One of the main reasons of unsustainability and inflexibility of dairy farms under study is the unsuitable use of resources and inputs. Therefore, the proposed model (Automata Resilience and Sustainability Indicator Model) was designed and optimized. Based on result the optimum resilience and sustainability achievable for the proposed dairy farm is 0.9598 (95.98%). Thus, the proposed model succeeds in determining the dairy farms' resilience and sustainability. Furthermore, it helps in setting up other operational parameters as determining the amount of cow manure produced, the man-working hours and labor expenditure.  The obtained results should be further used as guidance for improving the resilience and sustainability of the manufacturing operation in dairy farms.   This study has introduced a formulation for a resilience and sustainability problem in process of production in the industrial dairy farm. The contribution of the proposed formulation is its ability to addresses all pillars of resilience and sustainability at the producing level. One of the main advantages of the proposed measure of resilience and sustainability is data collection that relies on data usually collected in all farms for revenue and cost analysis, cattle diet and quality control. This fact makes the model applicable to facilities introducing resilience and sustainability concepts. Thus contributes to promoting the implementation of sustainable practices in agricultural production, especially in developing countries, where still have a lack of resilience and sustainability awareness and related legislation. Using weight is important to the application of the objective function and also makes the model suitable for its intended usage in the dairy farms of developing countries. This model is applicable in the area of the optimum dairy cattle nutrition, rising profitability, reducing feed cost, decreasing GHG, managing the water and energy consumption, etc., by maximizing resilience and sustainability in dairy farms. Additionally, the results allow also for identifying the prospective measures for improving resilience and sustainability. Through results analysis, a strategy for developing resilience and sustainability can be well defined. Furthermore, the current research can be extended by integrating the model with life cycle assessment results, another producer support policies, dairy farms' capacity expansions and could also be applicable to other forms of agricultural systems by a bit changes in the decision variables and model parameters.4- This data was gathered based on non-random sampling. Because, in non-random sampling, the sample individuals are selected among individuals who have a defined characteristics and based on researcher's opinion. The proposed model is designed for a sample dairy unit. In other words, the data obtained from non-random sampling were used only to determine the status of the studied samples.