水环境治理PPP项目合同柔性对项目融资风险的影响

为降低水环境治理PPP项目融资风险,结合合同柔性、PPP项目预期收益、信任与融资风险构建理论模型,探究合同柔性对项目融资风险的影响机理。研究结果表明:合同价格柔性、再谈判柔性、激励柔性均显著负向影响融资风险;PPP项目预期收益在价格柔性与融资风险关系中起完全中介作用,在再谈判柔性、激励柔性对融资风险影响中起部分中介作用;善意信任能增强价格柔性与激励柔性对融资风险的负向影响,但会减弱再谈判柔性的负向影响;能力信任在价格柔性与再谈判柔性对融资风险关系中起负向调节作用。研究从优化合同条款、创新回报机制、评估信任水平等方面为降低项目融资风险提供可行性建议。     

Urban water management: optimal price and investment policy under climate variability*

Australian urban water utilities face a significant challenge in designing appropriate demand management and supply augmentation policies in the presence of significant water scarcity and climate variability. This article considers the design of optimal demand management and supply augmentation policies for urban water. In particular, scarcity pricing is considered as a potential alternative to the predominant demand management policy of water restrictions. A stochastic dynamic programming model of an urban water market is developed based on data from the ACT region. Given a specification of the demand and supply for urban water state dependent optimal price and investment policies are estimated. The results illustrate how the optimal urban water price varies inversely with the prevailing storage level and how the optimal timing of investment differs significantly between rain dependent and rain independent augmentation options.     

Optimal management of a flammable forest providing timber and carbon sequestration benefits: an Australian case study*

In deciding to keep or fell a forest stand given its age, the risk of loss of timber through wildfire is an important consideration. If trees also have value from sequestration of carbon, another effect of fire is the unplanned loss of stored carbon. Factors affecting the decision to keep or fell trees, and how much to spend on fire protection, are investigated using stochastic dynamic programming, using carbon sequestration in stands of mountain ash in Victoria as a case study. The effect of treating sawlogs as a permanent carbon sink after harvesting is explored.     

Investment in site-specific crop management under uncertainty: implications for nitrogen pollution control and environmental policy

This paper applies an option‐pricing model to analyze the impact of uncertainty about output prices and expectations of declining fixed costs on the optimal timing of investment in site‐specific crop management (SSCM). It also analyzes the extent to which the level of spatial variability in soil conditions can mitigate the value of waiting to invest in SSCM and influence the optimal timing of adoption and create a preference for custom hiring rather than owner purchase of equipment. Numerical simulations show that while the net present value (NPV) rule predicts that immediate adoption is profitable under most of the soil conditions considered here, recognition of the option value of investment indicates that it is preferable to delay investment in SSCM for at least 3 years unless average soil quality is high and the variability in soil quality and fertility is high. The use of the option value approach reveals that the value of waiting to invest in SSCM raises the cost‐share subsidy rates required to induce immediate adoption above the levels indicated by the NPV rule.     

On the co-existence of spot and contract markets: the delivery requirement as contract externality

A contract between an upstream and a downstream party consistsof a contract price and a delivery requirement. Contract formationentails an externality. It changes the probability distributionof the spot market price by removing high reservation pricebuyers and various sellers from the spot market. The first effectdecreases the expected spot market price when the number ofcontracts is small, whereas the decrease in the number of sellersand additional residual contract demand increase the expectedspot market price beyond a certain number of contracts. It impliesan endogenous upper bound on the number of contracts. Contractprices are positively related to the number of contracts. Finally,additional contract formation reduces the variance of the spotmarket price when the number of contracts is sufficiently large.     

Modelling hydroclimatic uncertainty and short‐run irrigator decision making: the Goulburn system*

Australia has an incredibly variable and unpredictable hydroclimate, and while irrigation is designed to reduce risk, significant uncertainty remains in both seasonal water availability (‘allocations’) and irrigation crop water requirements. This paper explores the nature and impacts of seasonal hydroclimatic uncertainty on irrigator decision making and temporary water markets in the Goulburn system in northern Victoria. Irrigation and water trading plans are modelled for the three seasons of the irrigation year (spring, summer and autumn) via discrete stochastic programming, and contrasted against a perfect information base case. In water‐scarce environments, hydroclimatic uncertainty is found to be costly, in terms of both the efficiency of irrigation decisions and the allocation of water via the water market.     

Joint production under uncertainty and multifunctionality of agriculture: policy considerations and applied analysis

The impact of various policy instruments on the production ofenvironmental goods that are complementary to or competing withagricultural commodities is analysed in the light of the uncertaintyin output prices and farmers' risk aversion. Some theoreticalassessments are first summarised and then tested on a case studyconcerning beef and grassland biodiversity production in Montsdu Cantal, France. The results of simulations carried out bymathematical programming farm-level models show that joint commodityand non-commodity production is nearly independent of the degreeof farmers' risk aversion, and that commodity-linked policyinstruments are not suitable for the production of environmentalgoods even under uncertainty.     

Panama disease and contract farming in the Philippines: Towards a political ecology of risk

Despite the vast research on contract farming by agrarian scholars, little is known about interactions between biological risks and the social–political effects of contracts. This study analysed contract farming arrangements in the export banana industry in the Philippines amidst an expanding epidemic of Panama disease. We developed a political ecology of risk approach to investigate how ideas about technological and biological risks are influenced by contractual arrangements, and we borrowed from Cultural Theory the insight that risk and blame are connected concepts, always political, and disadvantage marginalized groups through disproportionate risk burdens. Data collection involved the study of contracts, interviews with decision‐makers, and focus group discussions with agrarian cooperatives. The views of both large corporations as well as organized smallholders were recorded. We found that the former contractually compel the latter to bear the burden of the disease, while blaming them for its spread. Risk decisions were embedded in the dynamics of agrarian social relationships, and economic and political arrangements between actors influenced possibilities and limitations for disease control. We argue that the contractual stipulations, in concert with blaming processes, create a discursive environment that both allow inequitable relations to remain unquestioned, and constrain possibilities for control of Panama disease.     

Regulatory Actions under Adjustment Costs and the Resolution of Scientific Uncertainty

Food system regulators often decide whether to ban existing practices or approve new technologies without conclusive scientific evidence on possible damage and knowing that resolution is likely in the future. In a model with three decision points and stochastic resolution of uncertainty, we study interactions between expected losses due to regulation and information availability when a regulator is deciding on an early reversible ban and on a later reversible ban. Adjustment costs create inertia concerning intermediate signals such that earlier decisions are not overturned, and also a bias against imposing an early ban. The prospect of more later-stage information can increase or decrease the incentive to ban early, but research decreases the incentive to ban early.     

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.     

Contract farming and everyday acts of resistance: Oil palm contract farmers in the Philippines

Contract violations are critical issues determining the success and sustainability of contract farming (CF). This paper challenges the common portrayal of the “powerful” company versus the “powerless” landowners/smallholders by using the literature on labour agency in global value chains to understand minor contract violations of contract farmers such, as side-selling, refusal to harvest, and burning/felling of oil palm trees. This paper conceptualizes these violations as acts of minor agency or everyday acts of resistance. The analysis highlights how CF has created chains of dependency, in which smallholders are integrated into the modern market economy through new relations of debt and power. In response, contract farmers attempt to influence and shape the CF relation by using these different acts of minor agency. This paper finds that acts of minor agency, in the aggregate, can have important effects on contract relations, governance, and organizational structure of the chain and has the potential to lead to broader changes in the underlying social relations of contract. It highlights how individual acts of minor agency may contribute to the development of a consciousness of collective opposition to the contract relation.     

Modelling a mixed system of air pollution fee and tradable permits for controlling nitrogen oxide: a case study of Taiwan*

A mixed-integer non-linear programming model that minimises the total regulatory costs of controlling nitrogen oxide is used to investigate how a newly proposed permit trading scheme in Taiwan, which incorporates the features of banking and a non-one-to-one trading ratio, may affect firms’ emission reduction strategies and permit trading decisions. Compared to the previous regulation where only an air pollution fee is used, the new regulation that requires a reduction in emissions by 10 per cent from the emission level in the year 2000 for a 5 year period will increase the costs by 77 per cent, which is equivalent to US$9.87 million. The design of banking and the increasing returns to scale characteristic of pollution control among firms might lead to an uneven reduction in emissions in each year. Setting a lower reservation rate for banking would, however, help maintain a more stable environmental quality without a significant loss to the government in terms of air pollution fee revenue.     

Land and contract farming: Changes in the distribution and meanings of land in Kilombero,Tanzania

In the context of contract farming of sugarcane in an outgrower scheme in Tanzania, this paper explores how the scheme has fundamentally altered people's relationships with the land over the last 50 years, in particular, since 1999, when, after three decades, the sugar parastatal was privatized. The paper reviews the literature on the mutual relationship between contract farming and land ownership and examines the scheme with a focus on long-term changes in the forms of land acquisitions and land use. We argue that the meaning and importance of landownership in contract farming schemes needs to be reassessed if participation in contract farming entails a departure from previous forms of acquiring land, generates new spatial patterns of agricultural production, and necessitates additional economic and social resources in order to transform land into an economic asset.     

Information exchange under uncertainty: The case of unconventional gas development in the United Kingdom

New techniques of unconventional oil and gas extraction, such as hydraulic fracturing, challenge current political, institutional and administrative practices in how to regulate activities in the underground. Conflicts of interests between economic promotion, landscape and natural resource protection, and new trends on energy markets are further intensified by the fact that techniques of oil and gas extraction come with a considerable amount of uncertainties regarding ecological and health impacts. Information exchange is one important aspect of how political actors try to reduce uncertainties and conflicts. Based on exponential random graph models (ERGM) for network data, we analyze to what degree ideologies, public authority, existing collaboration and scientific expertise drive information exchange in hydraulic fracturing regulation in the United Kingdom. Results show that technical and political information exchange have to be disentangled, and that the former is driven by expertise and existing collaboration, the latter by ideology, public authority and existing collaboration.     

The potential impact of markets for irrigation water in Italy and Spain: a comparison of two study areas*

The viability of irrigated systems in Southern Europe is closely linked to efficient institutional settings and water‐allocation mechanisms. A significant, although not widely used, mechanism for water allocation is an intra‐sectorial water market. The objective of this paper is to evaluate to what extent water markets may contribute to the improvement of the efficiency of water allocation and to the profitability of irrigated agriculture. The related issues of water allocation among farm types and farm specialisation are also addressed. The analysis is based on a basin‐level linear programming model, comparing the situation with and without a market. It includes both fixed and variable transaction costs and estimates their combined effects on market performances. The model is applied in two areas in Southern Italy and Spain, and simulates the behaviour of different farm types, derived from cluster analysis on a sample of farms in each area. The paper confirms that water markets could potentially improve the economic efficiency of water use, in terms of higher profit per hectare, given limited water availability. The potential improvements are associated with a more intense specialisation of farms and are strongly differentiated among farmers, particularly where significant restrictions to water availability occur. This corroborates the expectations of institutional difficulties in implementing water markets. However, the exchanges, and consequently the potential effects of water markets, are heavily affected by the actual level of water availability, as well as the size and the structure (fixed vs. proportional) of transaction costs. The paper calls for a more in‐depth analysis of the connections between market performances and institutional settings, as related to the issue of water‐agriculture policy design and coordination.     

政府间竞争影响城市土地市场化水平的双边效应研究：基于财政竞争和引资竞争的不同作用

研究目的:本文将政府间竞争划分为财政竞争和引资竞争,比较两者对城市土地市场化水平影响的大小,分析政府间竞争与城市土地市场化水平之间的关系。研究方法:基于2003—2016年全国284个地级市的面板数据,利用双边随机前沿模型测算财政竞争和引资竞争对城市土地市场化水平的影响。研究结果:财政竞争对城市土地市场化水平具有正向效应,提高了城市土地市场化水平1.61%;引资竞争对城市土地市场化水平具有负向效应,降低了城市土地市场化水平12.51%;政府间竞争总体上降低了城市土地市场化水平10.90%。时间趋势表明,政府间竞争对城市土地市场化水平的抑制作用呈现波动下降的状态。研究结论:政府间竞争降低了城市土地市场化水平。