جستجوی مقالات مرتبط با کلیدواژه « ارزش گذاری مشروط » در نشریات گروه « کشاورزی »

from anyone and they are effective in all aspects of urban life. on the other hand, they provide an environment for cheap recreation and relaxation for the residents and Forthermon, they play a significant role in reducing pollution (sound, heat and air). Among Iranian cities, Tabriz has the lowest number of parks per capita. Also, among the urban areas of Tabriz, district four, in which the construction site of the park is located, is in an unfavorable condition with a per capita green space of 4.92 square meters. If the Tabriz Grand Park project is completed, the area's per capita green space can increase up to 24 meters and the per capita green space of Tabriz city can increase from 6.76 square meters to 11.6 square meters. This research can be effective in introducing the capacities and calculating the hidden values of Tabriz Grand Park so that everyone will be aware of its economic and environmental potentials. Therefore, in this research, the economic and environmental effects of the construction of Tabriz Grand Park have been evaluated.

Forest and rangeland by-products, particularly medicinal plants, can contribute to sustainable development and increase economic opportunities for local communities. Medicinal plants play a significant role in society's health and disease treatment. Negligence to the preservation of medicinal heritage reserves in the field of natural resources will lead to disastrous consequences in the country's natural resources sector. Among these consequences are the rapid extinction of species and severe genetic erosion. Therefore, this study targets protection value and people's willingness to pay for medicinal plant protection and restoration. The Salas Babajani region in Kermanshah province was chosen for this research. The vegetation in this area is mainly wooded, and most of the area is covered by dense forests. Due to its diverse topography, the Salas Babajani region has a variety of forest habitats and rangeland and forest medicinal plants. Asafoetida, Thyme, Hawthorn, Wormwood, Eremurus, Dog rose, Chamomile, Sweet violet, Oak, Ferulago, Common Thistle, Horsemint, licorice, etc., are among the medicinal plants of this region. Contingent Valuation Method (CVM) was used to estimate medicinal plants' non-use (protective) values in this study. Also, a Double-Bounded Dichotomous Choice questionnaire was used to measure people's willingness to pay for medicinal plant protection in the region. The questionnaire was designed in two parts: socio-economic characteristics of people (age, gender, level of education, occupation, number of family members, income, and other characteristics of the respondents) and questions related to the willingness to pay of the respondents. Sampling was done by simple random sampling among residents of the Salas Babajani region in 2016. Cochran's formula from 353 questionnaires determined the number of samples. The logit model was used to measure people's willingness to pay, and the parameters were estimated based on the maximum likelihood method. The results showed that 64% of the interviewees were men and 36% were women. The average age of the respondents is 27.88 years, the average household size is 4.46, and their minimum and maximum household sizes are one person and ten people, respectively. The results also showed that more than 76% of people (269 samples) are willing to pay an amount to protect and restore medicinal plants. The average willingness of each person to pay annually for the protection and restoration of medicinal plants is equal to 5269 Tomans (according to the average household size (4.46 people) equal to 23500 Tomans for each household per year). The variables of household size and the suggested price have a significant negative effect with 95% confidence. The variables of income, gender, level of education, supporting the protection of natural resources (interest in the environment), and knowledge of the protection of medicinal plants and its relationship with sustainable development (knowledge and awareness of environmental protection) are among the most important positive influencing factors with 95% confidence on people's willingness to pay for the protection of medicinal plants. The variables of age, marital status, occupation, membership in environmental organizations, and environmental attitudes and tendencies did not affect the acceptance of the suggested price for medicinal plants conservation value. The Likelihood Ratio statistic (280.39) shows that the changes explained by the logit model are significant at a level higher than one percent. The estimated model's correct prediction percentage is also 75%. Since the percentage of correct prediction for the logit model is equal to 70%, the percentage of correct prediction obtained in this model seems favorable. Therefore, this model is reliable for further analysis. McFadden's coefficient of determination also shows that the model's explanatory variables explain well (about 0.87) the changes in the dependent variable. In terms of management, this study achieved promising results because it shows that the people of society are aware of the importance of protecting medicinal plants, and there is a desire to pay significantly for the protection and restoration of these valuable resources. Therefore, it is suggested that the government pay more attention to public participation to protect, revive, and develop medicinal plants in the forest areas of the study area.

Designing hypothetical markets and utilizing stated preference models, such as the Contingent Valuation Method (CVM), to assess the value of non-market services provided by natural and environmental resources is accompanied by various problems. These problems can be broadly categorized into two groups according to Williams (2016). Firstly, there are challenges related to the initial stage of study design, which occurs before estimating the econometric model. Secondly, there are problems related to selecting, estimating, and interpreting the results derived from the models. These challenges include selecting the appropriate model type, conducting estimations and ultimately, interpreting the results correctly (Williams, 2016).

In natural resource valuation research, logistic models are commonly employed in various forms including ordinary logistic regression, conditional logistic regression, ordered logistic regression, multinomial logistic regression, as well as other forms like mixed logit and nested logit (Baker and Ruting, 2014; Greene, 2018). This study thoroughly analyzed the interpretability of logistic regression in the normal logistic mode and it was preferred using the risk ratio index over the odd ratio index, because it was found to be more practical. However, the study mainly aimed at calculating the extent of changes in the probability of an event occurring, rather than representing its multiplication. This notion was quantified and articulated through the concept of marginal effect. In the studies conducted in Iran, the values of marginal effect were typically measured and expressed based on the average level of the considered independent input and the average of other independent inputs in the model. In addition, however, the marginal effect concept for each independent variable can be measured and expressed in three different ways (Williams, 2020): 1) Marginal Effect at the Means (the means of independent variables) (MEMs), 2) Average Marginal Effects (AMEs), and 3) Marginal Effects at Representative Values of independent variable (MERs). To calculate the marginal effect in each case, the Adjusted Prediction (AP) index should be calculated. This index is measured in three different ways, depending on the type of marginal effects used in the calculation (Williams, 2020): 1) Adjusted Predictions at the Means (APMs) (Means of Independent Variables), 2) Average Adjusted Predictions, and 3) Adjusted Predictions at Representative Values of Independent Variables. To assess the recreational value of Avidar Lake in Nowshahr County of Iran, the Contingent Valuation Method (CVM) and the One-and-One-Half Bound (OOHB) model were used. During the summer season of 2019, a total of 270 questionnaires were filled out. The odds ratio, risk ratio and marginal effects Indexes were estimated by Eviews software. 

The study findings indicated slight variations in the calculations of Marginal Effects of Means (MEMs) and Average Marginal Effects (AMEs). Furthermore, the results of Marginal Effects at Representative Levels (MERs) calculations demonstrated changes in the marginal effect values of independent variables across different levels of these variables. The average amount that the users were willing to pay for each leisure visit to Avidar Lake was determined as 334900 IRI rials by integrating the area under the curve of visitors' demand. Additionally, the annual recreational value of the lake was calculated to be 8650 million IRI rials. This value would reflect the economic potential of Avidar Lake in terms of creating recreational opportunities. 

Based on the study findings and to enhance its applicability in real-world scenarios and improve its effectiveness in practical policies, it is recommended that studies focusing on the assessment of natural resources and the environment prioritize the calculation of comprehensive outcome indicators using the specific details outlined in this study. More specifically, the study results demonstrate that evaluating the average result across various levels of variable values (rather than solely considering the average value) can effectively capture and illustrate the diverse impacts resulting from policy implementation at these different levels (in terms of the intensity of change impact).

Babolsar Township is the host of many tourists around the country annually.  The landfill of this township has located in the vicinity of the coast and on the other hand, due to proximity to residential, service, recreational, unsuitable conditions due to the emission of biogas and creating unpleasant odors in the region. due to the importance of the subject, in this research, the economic damage caused by the emission of unpleasant odors from this landfill, using the method of contingent valuation in the form of one and on-half dichotomous choices method and according to the Cochran formula, among 195 selected sample of indigenous and tourists of babolsar have been estimated. The results of logit model estimation on the basis of final effect showed that the proposed price variables, income, ethic-consequences desires and environmental trends have the greatest influence on the people's willingness to pay. The total economic damage costs to the society duo to the spread of the unpleasant odor of biogas of landfill has been estimated to be 42.759 billion Rials.

Bread holds a crucial position in Iranian cuisine and encompasses various types such as Barbari, Lavash, and Sangak. However, these bread varieties are often made from refined flours, lacking the nutritional benefits of whole grains. Reports from the Statistical Center of Iran indicate that bread purchases constitute a significant portion of household expenses. Recent studies have raised concerns about the adverse health effects associated with excessive consumption of refined bread, potatoes, and rice, including diabetes, indigestion, obesity, cardiovascular issues, and digestive system disorders. These concerns highlight the limitations of whole grain food consumption, such as whole wheat-grain bread. To address these health concerns, it becomes necessary to provide stronger incentives or encourage individuals to incorporate more whole grain products into their diets. Thus, the present study aims to analyze the factors influencing households' willingness to pay extra for whole wheat-grain bread, specifically Lavash and Sangak, in the city of Tabriz over a specified time period. By examining these factors, valuable insights can be gained to promote the consumption of healthier bread options and enhance public health outcomes.

To achieve the research objective, a questionnaire was developed, and data was collected through a random sampling method from households residing in the ten provinces of Tabriz city. Face-to-face interviews were conducted with 302 households during the summer of 2020. The data obtained from the questionnaire was analyzed using statistical and empirical techniques, specifically the Contingent Valuation Method (CVM), Sequential Logit (LS) model, and Generalized Sequential Logit (GSL) model. To ensure the validity of the models used, the Brant test of parallel regression was applied. This test evaluated whether there was proportionality in the odds model for ordinal logistic regression. It examined whether the observed deviations from our ordinal logistic regression model were significantly larger than what could be expected due to chance alone. This assessment helped ensure the reliability and accuracy of the statistical analysis conducted in the study.

The results of the study indicate that a high percentage of households in Tabriz city, specifically 90.73% for Lavash bread and 93.38% for Sangak bread, were willing to pay extra for whole wheat-grain options. Among the households, 40.4% expressed their willingness to pay less than 20% extra for the bread, while 26.82% were willing to pay more than 50% extra. Several factors were found to influence households' willingness to pay for whole wheat-grain bread. Positive effects were observed for the health index, knowledge of the benefits of whole wheat bread, education level, family income, presence of elderly individuals in the family, and frequent consumption of whole wheat Lavash bread. However, gender had a negative effect on households' willingness to pay for whole wheat-grain Lavash bread. Similarly, for whole wheat-grain Sangak bread, the health index, knowledge of the benefits of whole wheat bread, family income, and the presence of a patient individual in the family had positive effects, while gender had a negative effect. As the null hypothesis of the parallel regression test was rejected, the Generalized Sequential Logit model was applied to analyze the effects of various factors on households' willingness to pay at different levels (0%, less than 20%, 21-30%, 31-40%, 41-50%, and more than 50%) for different types of whole wheat-grain bread. The results of the model yielded different outcomes. Increases in the health index, awareness of whole wheat bread, family income, education level, presence of a patient individual in the family, and frequent consumption of whole wheat bread positively influenced households' willingness to pay more for both Lavash and Sangak bread. Education level and the presence of a patient individual in the family acted as incentives for whole wheat-grain Lavash bread, while gender and the number of household members deterred households from paying more. The general index of bread purchase was the only factor influencing households' willingness to pay more for whole wheat-grain Sangak bread. Education level, knowledge of the benefits of whole wheat bread, gender, and the number of household members had a negative impact on households' willingness to pay for Sangak bread. Moreover, the marginal effects of the coefficients were estimated at different levels, indicating how changes in the independent variables (such as health index, general index of bread purchase, awareness of whole wheat bread, family income, education level, knowledge of the benefits of whole wheat bread, frequent consumption of whole wheat bread, number of household members, presence of elderly individuals in the family, and presence of a patient individual in the family) affected households' willingness to pay for whole wheat-grain bread.

 According to the results, limitation in producing, supplying, and distributing the whole wheat-grain breads across the city, lack of easy access to whole wheat-grain stores, high prices, remote locations for purchases, and family awareness were the main and significant factors of using whole wheat-grain Lavash and Sangak breads among the Tabriz households. In this regard, the following policies were recommended: 1) Increasing the number of whole wheat-grain breads baking units and purchasing stores, 2) Group media can help to the acculturation and adaptation to the consumption of the whole grain bread, 3) Increasing awareness of whole wheat-grain bread benefits on health could be effective steps on the consumption of whole wheat-grain breads in Tabriz city.

Wetland mangrove forests, are one of the unique ecosystems that provide a wide range of functions and ecosystem services such as food production, water purification and cleansing as well as providing the habitat and nursery grounds for birds and the other aquatic organisms. Despite the numerous and unique values, these ecosystems are now subject to a diversity of pollutions and threats caused by human activities, have become sensitive ecosystems with severely in need of protection. To achieve this goal- the WTA of local communities living in the areas adjacent to these forests was evaluated based on data derived from questionnaire surveys. The CVM questionnaires with dichotomous choice format were carefully designed with WTA measure and local people were asked about their preferences for reduction of access to Hara forests under hypothetical scenarios in which they would receive monetary compensation for lessening or forgoing forest utilization. The results of binary logit model for CVM survey data showed that 99 percent of respondents willing to accept a reduction in their forest utilization and participate in the protection programs. The mean WTA estimated 2110274 Rial/household/day (63308220 Rial/month).

The diverse ecosystem of the Sea has brought about the formation and continuous flow of products and services for people beings and its effects on the economic life of countries have valuable roles. To evaluate these services, it is necessary to identify the benefits and select the appropriate product. Valuation of shrimp ecosystem services was done by evaluation methods. Samples (70-person from stockholders) are select in two groups of Eco-Friendly and fishers and their opinions on shrimp’s value ​​were collected using a questionnaire. Contingent valuation and Benefit Transfer Method were calculated in 1400. The results showed the existence value of banana’s shrimp (Penaeus merguiensis) was obtained as 9.38% of its market price (one million Rials).The bequest value of this benthic species was estimated to be at least 2.5 million Rials per person and the value of other species associated with fishing was estimated to be about 1.3 million Rials. Damage to marine resources was estimated at more than $ 140 million by overfishing and other non-target species (by-catch). Assessing the total value of ecosystem services and shrimp productions in 1400, more than $ 53 million was obtained and the damages of this economic activity are estimated to be more than 2.3 times the calculated values. Therefore, changing harvest and trawl methods are applied suggestions.

Contingent valuation is one of the standard methods is utilized to estimate the value of non-market goods and services. Recently, this method is used in Iran frequently. Much more studies were designed using DBDC but analyzing their data was done using logit model that is suitable for analyzing SBDC data. Also, there are some studies designed by SBDC and analyzed using logit model. The main purpose of using DBDC is to increase statistical efficiency of the estimates, but efficiency does not increase when logit model is used for its data analysis. The main goal of this paper is to analyze SBDC data using logit model and DBDC data using seemingly unrelated bivariate probit regression (SURBP) and compare statistical efficiency of these estimates. The results showed that the variance of the coefficients of all variables in the SURBP model is less than the logit model. Also, the amount of willingness to pay in SBDC and DBDC methods was estimated 6524 and 6437 Rials, respectively; and the estimated confidence interval of the willingness to pay in the DBDC method is less than the SBDC. It is suggested that if the DBDC elicitation method is used to estimate the willingness to pay, the data be analyzed using the SURBP model.

Water is a socio-economic commodity which is considered as a basic human need. Limited water resources in arid and semi-arid regions and increasing demand for water has led to water shortages, reduced reliability of water supply systems, and intensified competition and conflict between different sectors of water consumption. Limited water resources have also caused economic, environmental, social and political tensions. Among the various uses of water, urban drinking water has a higher priority due to health issues, basic human needs and the possibility of social tensions due to its scarcity.Water pricing as a tool for demand management, whether through administrative decrees or market forces, is the best approach to improve water allocation and protect water resources. Considering the importance of determining the economic valuation of water in the study area and with the aim of determining the customers' willingness to pay for quality drinking water, this study was intended to estimate the economic valuation of water in urban areas of Hamadan province.One of the methods of water valuation is measuring the willingness of consumers to pay higher prices for quality water. The contingent valuation method as a standard and flexible method is widely used for measuring the willingness of consumers to pay higher prices for quality water (Khodaverdizadeh et al., 2008). Comparing the willingness to pay in urban and rural areas in Kenya, Brouwer et al. (2015) found that rural households were more sensitive to prices than urban ones, and urban households were willing to pay more for quality water than villagers. Acey et al. (2019) also examined the willingness to pay for water by Kenyan citizens. The results showed that among citizens who were younger and richer, the willingness to pay was higher. Considering the importance of determining the economic valuation of water, this study was thus intended to determine the rate of willingness to pay for quality drinking water by the households in Hamedan province using a contingent valuation method.

Desert ecosystems have a considerable potential to attract domestic and foreign tourists, and it is essential to pay attention to their market and non-market values in sustainable economic development. The purpose of this study is to estimate the conservation value of Khoor-o-biabank city and investigate the factors affecting people's willingness of people to pay for the protection of this area using the logit model and the maximum likelihood estimation method. For this purpose, 388 questionnaires from the visitors of the studied area were collected and analyzed using the conditional valuation method using the two-dimensional double choice extraction method. The analysis of the collected data showed that 71.8 percent of people are willing to pay for the protection of the area, which indicates its high importance from the point of view of visitors. Also, the results show that the maximum willingness to pay each person for the protection value of the area is 108,540 Rials. Based on this, the annual protection value was determined as 4,228 million Rials. Gender, occupation, frequency of visits to the region, importance to the environment, income and membership in environmental protection organizations have had a positive and significant effect on the willingness to accept the proposed amounts. The results of the present research can help the managers of the tourism field in the planning of the province in improving the tourism conditions and also prioritizing these points.

Rapid mass migration to cities and economic growth have created various problems for sustainability. The ever-increasing increase in urban waste, which causes environmental pollution and land occupation, that has been concerns of municipalities, and separate collection is known as a suitable method for their disposal. Municipal waste - always as a pollutant, has polluted the environment around human and reduces the beauty of cities. Ardakan city, also the same oflike many industrial cities in Iran, has many problems in the field of urban waste management due to the rapid growth of urbanization. Therefore, the present study has determined the economic value of the green tax in Ardakan city and measured Pepole`s willingness to pay for the suitable separation and disposal of waste using the contingent valuation method (CVM) and the two-dimensional dual technique. The required data was obtained through distribution of 608 questionnaires in Ardakan in 2018. The results of the logit model estimation show that age and gender variables have a negative impact, and the variables of the number of household members and education have a positive and significant effect on the acceptance of the proposed amount. The amount of People's willingness to pay monthly was obtained, equal to 23450 rials (0.55 $), since this amount is for providing services to the person, it can be paid as a green tax for proper waste separation and disposal for each person. Also, the total value of green tax is equal to 21181 million rials (504315.7 $) per year. The income from people's willingness to pay for proper waste disposal can be used for the costs of installing bins for waste separation and finally disposal or recycling of waste, creating employment in this sector.

Desert ecosystems have substantial economic potentials that paying attention to them to attain sustainable development and to get rid of the one-product economy is essential. According to the growing demand for ecotourism, calculating the recreational value of recreational areas seems to be necessary for efficient and effective management. The purpose of this study is to determine the factors affecting the willingness of tourists to pay in the Qaleh-Bala area of Biarjamand city in Semnan province. To examine the factors affecting the willingness to pay, the Logit model was estimated by the maximum likelihood method. To measure the willingness to pay off the Qaleh-Bala Double-bounded Dichotomous Choice, it was used. The required data were prepared and collected by completing a questionnaire and face-to-face interviews with visitors from the area. The tourist samples were selected by a simple random sampling method for 207 people, and then the questionnaires were completed by them. The results of the Logit model showed that the coefficients of the variables number of visits, final destination, and distance from residence, monthly household expenses, and offered price were significant at the level of 1% and 5%. Finally, the average willingness to pay for the use of the area by visitors was 48,220 Rials and the annual recreation value of Qaleh-Bala village was estimated at 434 million Rials

Extra livestock than grazing capacity is one of the main effective factors on rangeland degradation. Most of the country's pastures have Extra livestock than grazing capacity, and from the past until now, the policy of dealing extra livestock by using legal punishments has not been able to completely solve this problem. Lack of attention to grazing capacity has led to the destruction of vegetation. The economic approach, the Payment for Ecosystem Services (PES), in return for the reduction of grazing capacity can contribute to rehabilitation of rangeland ecosystems which are getting degraded. One of the basic measures in this regard is to determine the Willingness to Accept (WTA) by the rangeland utilizers.

In this research, in the statistical society of ranchers in the rangelands of Bardeh and Kresnak regions in Ben city of Chaharmahal va Bakhtiari province, after classifying the ranchers, sampling and interview were performed randomly in each category. Data were collected through regular and guided interviews and questionnaires. In this section, two scenarios were analyzed. Scenario 1 Based on the questionnaire, the annual profit of each sheep and goat productive livestock was asked directly from the rancher. In the second scenario, the net income from each animal unit was determined by calculating costs and revenues, and the amount of lost pastoral income due to the elimination of one animal unit was determined. The two values ​​calculated in the scenarios were compared and the second scenario, which was more accurate as a quantitative number, was introduced to the respondents. The willingness to pay (WTA) of ranchers in return for the grazing livestock elimination was determined by conditional valuation method (CVM), using the logit function. Role of the law and Existing instructions on PES was investigated by Content analysis method.

Results showed that 71.4% of ranchers agree with PES in return for the grazing livestock reduction. The WTA in return for elimination per A productive sheep and goat are determined to be 7265 and 6462 thousand Iranian Rials per year, respectively which is lower than the net income per animal unit. The share of the pasture from the net income of a sheep and a productive goat in the permitted utilization conditions, which are set for one hundred days, is set at 1990 and 1770 thousand Rials, respectively. In the current utilization conditions, the dependence of livestock on rangeland during the year is 44.4%. The outputs of the logit model show that the WTA ranchers increase with the bid price (P = 0.00). There is significant relationship between WTA and the number of grazing livestock (P<0.01). Instructions for terms of rangeland utilization have been prepared and reviewed 5 times. The executive procedure for calculating the customary rights of ranchers has also been prepared and revised by the Cabinet of Ministers in 1391 in 3 times, in 1395, 1398 and 1399, with the approval of its executive regulations. An analysis of the content of these guidelines reveals that is not mentioned payment for ecosystem services.

 A comparison between the first and second scenarios shows that the net income of an animal unit in the first scenario is higher than the second scenario, and the reason for this difference can be related to the income effect. That is, if a higher amount is answered by ranchers in the interview, they will gain more benefits. The minimum level of Payment for Ecosystem Services per animal unit should be equal to that of the profit per animal unit. Investigation of the laws and regulations related to the rangeland shows that yet no law or regulation have been enacted in terms of the PES, in return for the elimination of grazing livestock and even it has not been mentioned in legal terms

Nowadays, the destructive factors of the environment and natural resources are so widespread that the alarm of destruction of these natural wonders is sounded all over the world. Due to the importance of this topic, the study was conducted to estimate the willingness to pay of local communities to conserve and restore desert areas of Gosht plain in Saravan in order to attract people's participation to finance projects for the preservation and rehabilitation of desert areas. The sampling process was conducted using Cochran's formula with 303 samples by simple random sampling method. Conditional valuation method and Logit model were used to estimate the people’s willingness to pay. The results showed that gender, education, participation in rural government institutions, employment of trusted executives, the history of participation in educational-developmental classes, being native, income and directly being beneficiaries from the environment of the region has a positive and significant effect on the willingness of people to pay for Gosht plain protection. The variable of age and suggested amount had a negative and significant effect on willingness to pay, but the size of household had no significant effect on willingness to pay. Moreover, the variables of existence of a management organization for participation, acquaintance with the environment, having environmental literacy, and government financial support of the projects had a positive and significant effect on the willingness to pay for the Gosht plain protection. The average of peoples’ willingness to pay monthly in 1398, was obtained 113890 Rials per each person.

Wetland services include recreational use, harvested meat (as direct consumption values) and carbon sequestration, oxygen production, water conservation and soil conservation (as indirect consumption values). In addition to use values, wetlands have other values; these values are the sums that individuals are willing to pay to protect wetlands for future use, for future generations to enjoy them, and for their mere existence. In this paper, the value of goods and services of Hamoon Wetland ecosystem in Sistan region in the form of information functions (recreational and protective values) in 2019 has been estimated. The information needed to estimate the value of these functions was collected using a questionnaire. Recreational and conservation values of Hamoon wetland as the recreational value of forest ecosystem of Hamoon wetland, was collected by collecting information from 350 people randomly in the villages around the wetland and the conditional valuation method. Based on the obtained results, the value of recreational and protective functions of Hamoon Wetland was estimated at 629.82 million Rials and 644.2 billion Rials, respectively. In case of collecting fees from visitors in order to use the recreational function of the wetland and its cost to maintain the wetland, it is possible to develop and preserve its existing values.

The aim of this study is to determine the optimal tariff for treated wastewater in the agricultural sector in the south of Tehran province. In order to achieve this goal, Used of positive mathematical programming (PMP) optimization method and the conditional valuation method (CVM) to estimate the conservation value. The required information was collected by completing 470 questionnaires by two-stage cluster sampling in the south of Tehran province in 2019. Based on the results, the cost price of treated wastewater was determined to be 21,523 Rial per cubic meter in Tehran province. Market price for each cubic meter of treated wastewater in Qarchak, Pishva, Rey and Varamin cities is 4444, 5556, 9778 and 5000 Rial respectively, value Marginal production is 10080, 15720, 17090 and 12370 Rial and willingness to pay of farmer 9474, 10136, 10173 and was determined to be 10671 Rial. Finally, by examining the conditions of market formation, the optimal tariff for treated wastewater in the south of Tehran province (PEWW) was determined to be 10,114 Rial per cubic meter. Due to the high cost price of each cubic meter of treated farmers are, it is suggested that the private sector enter the wastewater treatment market, because it can pay the difference between the cost price and the willingness to pay of farmers for the treated wastewater from government environmental assistance.

The dust has become one of the most dominant environmental crises in some parts of the world especially in Sistan and Nimrooz in recent decades due to the increase in severity, duration and frequency of its occurrence. This study aims to evaluate the economic damage of the dust on the agricultural sector in Nimrooz city through the assessing of its impact on the agricultural sector. To collect required data, a questionnaires were developed in which not only some questions of people's willingness to pay for their support and protection to deal with dust were included but also a number of questions about their demographic characteristics were added. After data gathering step, we use Logistic regression model and perform the model by the maximum likelihood approach. The results showed that 82% of the surveyed people have shown some willing to pay to deal with dust damage. The average willingness to pay is 377060 Rial per month. The results also showed that the dust is the most important problem for the residents of Nimrooz city and most people in the region. They also want to actively participate in controlling dust besides their willingness to pay. In this regard, it is suggested that due to the importance and participation of people in dust control, policy makers use the results of this study for better planning to control dust pollution

Due to the problems and diseases caused by pollutants due to the existence of industrial centers in Ardakan city, it is necessary to find solutions such as installing air filters, taxing pollutants and increasing fuel prices to eliminate or reduce pollution, according to the profitability of companies in To be considered. Therefore, the purpose of this study is to provide a solution to green tax to reduce environmental risks. In this study, Contingent Valuation method was used in the form of two-dimensional technique and logit econometric model. Also, to collect data from 608 questionnaires in order to pay people in 1396 in two parts: air pollution caused by factories and installation of signs and banners in the city to encourage people to use public transport and identify vehicles with defects Have technical, was used in Ardakan city. The results showed that the willingness of people to pay to reduce air pollution from factories is 32800 Rials and to reduce air pollution from transportation is 28650 Rials per person per month. The variables of car air pollution fines and rising fuel prices have a positive and significant effect on people's willingness to pay. Also, the variables of the proposed amount and income are the most important influential factors in both sectors. In total, the amount of green tax resulting from the two polluting sectors of industry and transportation in Ardakan city is 72,235 million rials per year, which can be used to establish non-governmental organizations to reduce air pollution.

This study aimed to improve the level of quality classification of saffron and increase farmers' profits by creating a hypothetical market to investigate the factors affecting selection and the willingness of farmers to pay for saffron quality testing using contingent valuation method and open-ended question. data were collected by a questionnaire from a random sample of 170 saffron producers in Khorasan Razavi province. Two-stage Heckman model was used to identify the factors influencing choice and estimation of willingness to pay. data analysis showed that about 48 percent of farmers are willing to pay an additional amount for a quality test, of which 29 percent showed willingness to pay more than 900,000 rials per kilogram of flower. The results of the model's estimation also showed that age, education, land ownership and history of saffron quality testing in the past have a positive and significant effect on the likelihood of choosing and the amount of willingness to pay extra for quality testing. Accordingly, the use of proper and comprehensive training, holding public organizations and promotional activities can play an effective role in encouraging farmers to conduct quality tests.Key words: Saffron, Willingness to pay, Contingent valuation, Two-stage Hackman model.This study aimed to improve the level of quality classification of saffron and increase farmers' profits by creating a hypothetical market to investigate the factors affecting selection and the willingness of farmers to pay for saffron quality testing using contingent valuation method and open-ended question. data were collected by a questionnaire from a random sample of 170 saffron producers in Khorasan Razavi province. Two-stage Heckman model was used to identify the factors influencing choice and estimation of willingness to pay. data analysis showed that about 48 percent of farmers are willing to pay an additional amount for a quality test, of which 29 percent showed willingness to pay more than 900,000 rials per kilogram of flower. The results of the model's estimation also showed that age, education, land ownership and history of saffron quality testing in the past have a positive and significant effect on the likelihood of choosing and the amount of willingness to pay extra for quality testing. Accordingly, the use of proper and comprehensive training, holding public organizations and promotional activities can play an effective role in encouraging farmers to conduct quality tests.Key words: Saffron, Willingness to pay, Contingent valuation, Two-stage Hackman model.

This study aimed to estimate the economic value of drinking water in Doganbadan using the contingent valuation method (CVM). In order to examine the economic and social factors affecting the willingness to pay, the logit econometric model was used. The required data were collected through a field study, questionnaire completion, and in-person interviews with 600 residents of Dogonbadan using the multi-stage cluster sampling method. According to the results of the study, 79% of people were willing to pay amounts to help improve the quality of drinking water so that they wished to pay the amount of 5666 Riyals per cubic meters per month to improve the quality of drinking water. As well as, on the basis of this study, gender variable had no significant effect on households' willingness to pay. Other variables of the model including age, education level, family size, monthly income, satisfaction with the quality of water, and bid price were significant. Thus, taking into account the high value and importance of improving the quality of drinking water, it is recommended that policies be adopted to maintain water quality standards.