Spot water markets and risk in water supply

Water availability patterns in semiarid regions are typically extremely variable. Even in basins with a highly developed infrastructure, users are subject to unreliable water supplies, incurring substantial economic losses during periods of scarcity. More flexible instruments, such as voluntary exchanges of water among users, can help users to reduce risk exposure. This article looks at the effects of spot water markets on the economic risk caused by water availability variations. Our theoretical and empirical risk analyses are based on the random profits of water users. Profit probability density functions are formally and graphically characterized for both water sellers and buyers under several possible market outcomes. We conclude from this analysis that, where water supply is stochastic, water markets unambiguously reduce both parties' risk exposure. The empirical study is conducted on an irrigation district in the Guadalquivir Valley (Southern Spain), where there is a high probability of periods of extreme water scarcity. Water demand functions for the district representative irrigators and a spatial equilibrium model are used to simulate market exchanges and equilibrium. This programming model is combined with statistical simulation techniques. We show that the profit probability distribution of a representative irrigator is modified if water exchanges are authorized, leading to risk reductions. Results also indicate that if the market were extended to several districts and users that are subject to varying hydrological risk exposure, extremely low‐profit events would be less likely to occur. In sum, we show that exchanging water in annual spot markets can reduce farmers' economic vulnerability caused by water supply variability across irrigation seasons. These results support the water policy reform carried out in Spain in 1999 to allow for voluntary water exchanges among right holders.     

Optimisation of water procurement decisions in an irrigation district: the role of option contracts

Water supply instability is one of the main risks faced by irrigation districts and farmers. Water procurement decision optimisation is essential in order to increase supply reliability and reduce costs. Water markets, such as spot purchases or water supply option contracts, can make this decision process more flexible. We analyse the potential interest in an option contract for an irrigation district that has access to several water sources. We apply a stochastic recursive mathematical programming model to simulate the water procurement decisions of an irrigation district's board operating in a context of water supply uncertainty in south‐eastern Spain. We analyse what role different option contracts could play in securing its water supply. Results suggest that the irrigation district would be willing to accept the proposed option contract in most cases subject to realistic values of the option contract financial terms. Of nine different water sources, desalination and the option contract are the main substitutes, where the use of either depends on the contract parameters. The contract premium and optioned volume are the variables that have a greater impact on the irrigation district's decisions.     

Coping with drought with innovative pricing systems: the case of two irrigation water management companies in France

In recent years, France has been facing particularly severe drought periods especially in summer. In a country where agriculture is the largest water user, some irrigation management companies have implemented innovative pricing systems to handle this situation. The objective of this article is to analyze the impact of these new management systems on farmers’ incomes, the revenue of the management companies, and the amount of water used. To do that, we develop a methodology using a stochastic model that simulates the representative farmer's optimal behavior in a context of climatic variability. An empirical application is made with a crop growth model and data collected from the Midi‐Pyrenees region. The results show that using these specific nonlinear pricing systems allow irrigation water managers to reduce the impact of drought on production. Moreover, the type of pricing implemented depends on the characteristics and capabilities of the water company. More particularly, these pricing systems can be used to anticipate agricultural water demand in order to avoid imbalance with water availability.     

Energy price reform and food markets: the case of bread supply chain in Iran

Reforming energy price is the core of Iranian economic reform plan during 2010–2014. However, increasing price of energy may have adverse effects on the agricultural and food markets. This study was conducted to address these problems in the most important food of Iranian people “bread” by developing a spatial supply chain model. Results show that consumers’ welfare would experience a sharp decrease though the impacts on farmers are trivial. Also, results indicate that the key to success the reform without political backlash in the short‐run is the cash transfer program under which the government redistributes part of the reform's benefits among consumers. Per capita compensation payments would be equal to 51.50 and 46.09 US$ per year for a typical rural and urban person, respectively. Moreover, the results provide more detailed information about the market characteristics and the payments both in nationwide and regional scale as well as in different income groups.     

Irrigation water pricing: differential impacts on irrigated farms

European water policy, as set out in the Water Framework Directive (WFD), requires all EU Member States to implement volumetric water pricing at rates that roughly cover the total costs of providing water services. The objective of this paper is to develop a methodology that, for the different types of farm in an irrigable area, will enable us to analyse the differential impact that a pricing policy for irrigation water would have. For this purpose, Multi-Attribute Utility Theory (MAUT) mathematical programming models were used. The methodology is implemented on a representative area in the Duero Valley in Spain. Our results show the usefulness of differential analysis in evaluating the impact of a water pricing policy. This allows significant differences in the evolution of agricultural incomes to be observed, as well as the recovery of costs by the State, demand for agricultural employment and the consumption of agrochemicals resulting from rising prices of irrigation water in various groups of farmers within a given irrigated area.     

Regional Planning of Wastewater Reuse for Irrigation and River Rehabilitation

Subject to a few agri‐environmental restrictions, municipal wastewater can be utilised for agricultural irrigation and river rehabilitation. This paper develops a single‐year Planning Model for a region in Israel which consists of a city and three potential wastewater consumers. The model incorporates, in one endogenous system, the economic, physical and biological relationships in the water–soil–plant–environment system and its objective is to maximise the regional social welfare. The model determines the optimal crop mix and the optimal allocation of the limited water and land resources among all potential users. Then, different allocation approaches from the concept of transferable utility games are applied to determine a reasonable and fair allocation of the additional net benefits which will be acceptable to all the players. The results support the collaboration among the economic entities and indicate economic and environmental advantages which can serve the decision‐makers.     

Irrigation technology adoption and its implication for water conservation in the Texas High Plains: a real options approach

Water shortage has been a significant issue for several decades in the Texas High Plains. Agriculture has been identified as the main activity contributing to this shortage. To address this issue, many efforts have been focused on the possible adoption of sophisticated irrigation systems with high levels of water application efficiency. In this study, the entry and exit thresholds for the low‐energy precision application (LEPA) system are analyzed simultaneously in cotton farming in the Texas High Plains using a real options approach. The results show that the LEPA system is profitable only when cotton price is set above $1.59/kg. The exit (entry) threshold is consistently low (high) over a range of values for parameter changes including investment cost, exit cost, variable cost, risk‐adjusted discount rate, and volatility rate, so it is unlikely that farmers with irrigation systems in place would leave them easily. This implies that to attain the goal of saving water, Lubbock County needs to focus on convincing current farmers to replace old irrigation systems with new ones.     

The role of common pool problems in irrigation inefficiency: a case study in groundwater pumping in Mexico

Groundwater depletion is a serious problem in Mexico. Several policy alternatives are currently being considered in order to improve the efficiency of irrigation water use so that extraction of groundwater is diminished. An understanding and quantification of different sources of inefficiency in groundwater extraction is critical for policy design. Survey data from a geographically extensive sample of irrigators is used to gauge the importance of common pool problems on input‐specific irrigation inefficiency. Results show that mechanisms of electricity cost sharing implemented in many wells have a sizable impact on inefficiency of irrigation application. Moreover, irrigation is very inelastic to its own unitary cost. Therefore, results suggest that policies aimed at eliminating electricity cost‐sharing mechanisms would be significantly more effective than electricity price‐based policies in reducing irrigation application. Results also show that well sharing does not affect groundwater pumping significantly, suggesting either a limited effect of individual pumping on water level or absence of strategic pumping by farmers sharing the wells.     

Impacts of changing water inflow distributions on irrigation and farm income along the Drâa River in Morocco

Irrigation water is essential for agriculture in the arid Drâa River basin in Morocco but climate change leads to increasingly unreliable water supply in the area. This article analyzes impacts of changing water inflow distributions on irrigation and farm income extending a conjunctive river basin model toward a stochastic modeling approach. Regional climate scenarios are used to derive a maximum likelihood density estimate of current and future water supplies. Based on these distributions, Monte Carlo simulations are performed to obtain stochastic model results on surface and groundwater irrigation as well as economic indicators for six oases along the river. The probability of farmers to receive revenues below the subsistence level is around 2% under current conditions, but this is likely to rise to rates of 6% to 15% depending on the underlying climate change scenario. The composition of water sources for irrigation will shift to more groundwater use. The river basin model is able to represent complex spatial interactions between oases as well as a partial complementarity between groundwater and surface water irrigation due to salinity management effects. Interestingly, the value of groundwater is not necessarily increasing under future climatic conditions as salinity problems are aggravated with expanded groundwater use.     

Modelling drought and recovery in the southern Murray‐Darling basin*

The prolonged drought from 2006–07 to 2008–09 in south‐eastern Australia presented severe difficulties for dry‐land and irrigation farmers in the southern Murray‐Darling basin. A dynamic multi‐regional computable general equilibrium model (TERM‐H2O) is used to estimate the economy‐wide small region impacts during and after drought. Drought reduces real GDP in some small regions by up to 20 per cent. Irrigation water trading and farm factor movements alleviate losses. The drought results in an estimated 6000 jobs being lost across the southern basin. Depressed farm investment during drought results in farm capital not returning to baseline levels after drought. Consequently, job numbers in 2017–18 remain 1500 below forecast in the southern basin.     

The Economic Benefits of Irrigation Districts under Prior Appropriation Doctrine: An Econometric Analysis of Agricultural Land‐Allocation Decisions

The economic literature has established that prior appropriation doctrine induces heterogeneity in risk among water users, which leads to an inefficient allocation of resources. In this study, we show that irrigation districts alleviate that risk by deviating from the strict application of prior appropriation doctrine. As a result, farmers inside irrigation districts are able to plant more water‐intensive crops than farmers outside irrigation districts, which increases average profitability. We empirically examine this hypothesis by leveraging a georeferenced panel data set at the spatial scale of the individual water right and spanning 2007–14 in Idaho's Eastern Snake River Plain. Our results indicate that on average, irrigation districts allocate larger portions of their land to drought‐sensitive, high‐value crops such as sugar beets and potatoes. As a result of differences in planting decisions, members of irrigation districts earn on average $16.20 per acre, or 6.0% more per year than those outside of irrigation districts.     

Analysis of a supply-control program under uncertainty and imperfect competition: Chinese cabbage in Taiwan

Researchers have often attributed the farm–wholesale price spread, after adjusting for marketing costs, as compensation for marketing firms' risk bearing. However, price spreads in excess of marketing costs can also be due to marketing firms' exercise of market power. In settings where both imperfect competition and marketer risk aversion are plausible, a modeling framework must be sufficiently general to accommodate both types of behavior. This article develops and estimates such a model in the context of fresh produce marketing and develops the implications for analysis of supply‐control programs. The model is applied to the production and marketing of Chinese cabbage in Taiwan and specifically to the analysis of supply‐control programs implemented in this industry by the Taiwanese government. The empirical results provide little support for the hypothesis that marketing firms exhibit risk averse behavior, but they do show that marketing firms exercise oligopsony power in procurement of the product from farmers, and that this power is positively related to the quantity supplied in each market period. This provides a heretofore unexplored impetus for supply controls intended to raise producer incomes. However, such controls are also rendered less effective by imperfect competition because marketing firms capture part of the benefits from supply reduction.     

Economic Analysis of the Policy for Accreditation of Dairy Farms Free of Bovine Brucellosis and Tuberculosis: Challenges for Small and Large Producers in Brazil

One of the cornerstones of the National Program for Control and Eradication of Bovine Brucellosis and Tuberculosis in Brazil is the voluntary accreditation of free herds. We developed a stochastic cost–benefit analysis model for two types of dairy herds (high yield Holstein‐Zebu crossbred females and lower productivity smaller scale herds) to identify the technical and economic constraints of this process. The initial prevalence of infected animals and the impact of the disease in the structure and performance of the herd were derived from secondary data. Information on the costs and benefits of herd sanitation were compiled into a cost–benefit model at the herd level. The last step consisted of a scenario simulation to evaluate the impact of alternative policies to the certification process. For each scenario, we calculate the probability over time of a Benefit–Cost Ratio greater than 1 and of an Internal Rate of Return above 1% (the discount rate used in the model). Results show that larger and more intensive dairy farms, and also herds affected by brucellosis compared with tuberculosis‐positive herds, are more likely to achieve financial gains from the certification investment. The compensation for culled animals is important in the initial phase of herd sanitation and the premium payment on milk would help farmers to achieve a return on the investment over time. The model can be adapted to different and dynamic production, epidemiological and economic settings.     

宁夏固海灌区可持续发展的思考

在总结宁夏固海灌区经济效益的基础上,分析了灌区多年来的用水量状况和灌区供水存在的主要问题。针对灌区运行管理中存在的问题,提出了增强运行管理单位的造血功能,创建多元化的供水市场,建立合理的水价机制,政府给予必要的扶持政策等建议。     

水肥一体化技术的环境效应与经济效应分析——基于山东省苹果种植户的调研数据

目的 绿色农业技术的环境与经济收益核算,对于推进技术应用、解决农业面源污染问题和实现生态文明建设具有重要的参考价值。究竟绿色农业技术有没有顺利实现农户的经济目标与社会的环境目标？现有研究诸多争议与困惑。方法 文章以水肥一体化技术为例,基于山东省649份苹果种植户的实地调查数据,借助内生转换模型,从微观层面探讨了水肥一体化技术的环境效应和经济效应。结果 （1）总体来看,农户采纳水肥一体化技术实现了节肥增收的目的。（2）采纳水肥一体化技术后,样本农户能够节约化肥施用量11.79%~20.98%,提高农产品收入8.15%~9.07%。（3）不同规模农户采纳水肥一体化技术的节肥增收效应存在显著差异。对于采纳水肥一体化技术的规模户而言,其化肥减量作用强度明显高于小规模农户。与此同时,采纳水肥一体化技术只对规模户有明显的农产品增收作用。结论 注重完善市场流通机制下农产品质量监督体系,使绿色农产品能够获得质量溢价的收益。同时创建有利于水肥一体化技术推广应用的土地规模条件,获得规模化带来的节肥增收效应。推动外部性内部化补偿制度实施,政府对具有正外部性行为的农户给予补偿。     

Macro–micro feedback links of water management in South Africa: CGE analyses of selected policy regimes

The pressure on an already stressed water situation in South Africa is predicted to increase significantly under climate change, plans for large industrial expansion, ongoing rapid urbanization, and government programs to provide access to water to millions of previously excluded populations. This article employs a general equilibrium approach to examine the economy‐wide impacts of selected macro and water‐related policy reforms on water use and allocation, rural livelihoods, and economy at large. The analyses reveal that implicit crop‐level water quotas reduce the amount of irrigated land allocated to higher‐value horticultural crops and create higher shadow rents for production of lower‐value water‐intensive field crops, such as sugarcane and fodder. Accordingly, liberalizing local water allocation within irrigation agriculture is found to work in favor of higher‐value crops, and expand agricultural production and exports and farm employment. Allowing for water trade between irrigation and nonagricultural uses fuelled by higher competition for water from urbanization leads to greater water shadow prices for irrigation water with reduced income and employment benefits to rural households and higher gains for nonagricultural households. The analyses show difficult trade‐offs between general economic gains and higher water prices, which place serious questions on subsidizing water supply to irrigated agriculture, i.e., making irrigation subsidies much harder to justify.     

Incentives to managers or participation of farmers in China's irrigation systems: which matters most for water savings,farmer income,and poverty?

The overall goal of our article is to better understand which matters for water savings, farmer income and poverty in China's irrigation systems: incentives to managers or participation of farmers. To pursue this goal, the article has three objectives. First, we track the evolution of water management reform, examining the practice of providing incentives to managers, and increasing the participation of farmers. Second, we identify the impact of water management reform on crop water use. Specifically, we want to measure whether or not incentives to managers and farmer participation in water management institutions affect the performance of the irrigation system. Because we also are interested in the potential results of water management reform, the article explores how changes in incentives and farmer participation affect farmer income and poverty. Based on a random sample of 51 villages and 189 farmers in four large irrigation districts in Ningxia and Henan provinces, both in China's Yellow River Basin, our results show that the two major forms of water management reform, water users' associations (WUAs) and contracting, have begun to systematically replace traditional forms of collective management. Our analysis demonstrates, however, that it is not the nominal implementation of the reform that matters, but rather it is the creation of new management institutions that offer water managers monetary incentives that lead to water savings. In contrast to the original design of China's reform policies, participation of farmers has not played a role in saving water. Importantly, given China's concerns about national food production and poverty alleviation, the reductions in water, at least in our sample sites, do not lead to reductions in income and do not increase the incidence of poverty.     

Farm demand for quality potato seed in Indonesia

Seed is the one of the most costly components of potato production in developing countries. Since potato is a vegetatively reproduced crop, diseases such as viruses build up and yield declines as tubers are saved from one harvest for use as seed the next season. Replacing farm‐saved seed with clean seed is one means to increase yield, but information asymmetry between buyers and sellers on seed quality may restrict market supply of this input. In this article we develop a model of the seed market in which clean seed is treated as a capital good providing benefits over several seasons. To determine farm demand for clean seed, we conducted a survey of 182 potato farmers in the major potato growing areas of Indonesia to elicit their perceptions of seed quality from different sources, and derive farmers' “willingness‐to‐pay” for quality potato seed. Results indicate that the effects of information asymmetry on seed supply may be partially offset by the “reputation” of specialized seed producers. Nevertheless, marginal returns to disease‐free seed appear to significantly exceed marginal costs, indicating that improving supply of quality seed will contribute strongly to productivity growth in potato. We discuss several policy options to encourage supply and utilization of quality potato seed.     

A general equilibrium analysis of conjunctive ground and surface water use with an application to Morocco

Groundwater resources (GW) account for nearly 30% of the world's sustainable water supplies. Yet, this resource, which is fraught with externalities, has largely been left unregulated. The economic literature on GW is predominantly of a partial equilibrium type. We analyze GW regulation in a general equilibrium setting, focusing on the stabilization value of GW under natural (drought) and economic (rural–urban water transfer) shocks. A general equilibrium approach allows evaluating direct and indirect effects of GW regulation on agriculture and nonagriculture sectors and extends the scope for water policy. The analysis is applied to Morocco by extending an existing computable general equilibrium (CGE) model to include ground and surface water (SW) resources. We study effects of (i) an increase in GW extraction cost (e.g., as a result of prolonged extraction beyond natural recharge that lowers the aquifer's water table), (ii) a transfer of SW from rural (irrigation) to urban (domestic) use, and (iii) a reduction of water availability due to severe drought. We estimate the value of GW and assess the direct (partial equilibrium) and indirect (general equilibrium) impacts. We find that GW plays a critical role in mitigating the negative effects of these types of shocks.     

Economic assessment of acquiring water for environmental flows in the Murray Basin*

This article is an economic analysis of reallocating River Murray Basin water from agriculture to the environment with and without the possibility of interregional water trade. Acquiring environmental flows as an equal percentage of water allocations from all irrigation regions in the Basin is estimated to reduce returns to irrigation. When the same volume of water is taken from selected low-value regions only, the net revenue reduction is less. In all scenarios considered, net revenue gains from freeing trade are estimated to outweigh the negative revenue effects of reallocating water for environmental flows. The model accounts for how stochastic weather affects market water demand, supply and requirements for environmental flows. Net irrigation revenue is estimated to be 75 million less than the baseline level for a scenario involving reallocating a constant volume of water for the environment in both wet and dry years. For a more realistic scenario involving more water for the environment in wet and less in dry years, estimated net revenue loss is reduced by 48 per cent to 39 million. Finally, the external salinity-related costs of water trading are estimated at around 1 million per annum, a quite modest amount compared to the direct irrigation benefits of trade.