The Allocation of Nutrient Load Reduction across a Watershed: Assessing Delivery Coefficients as an Implementation Tool

Delivery coefficients have long been used in economic analysis of policies that seek to address environmental problems like water pollution. However, the derivation and validity of delivery coefficients have not been examined carefully by empirical analyses. We derived estimates of delivery coefficients and then evaluated them as a bridge between complex simulation models and economic policies like water quality trading. We found that the allocations achieved outcomes that differed from intended water quality targets by less than 10% in most cases. For the least-cost allocation with heterogeneous costs, cost savings significantly outweighed deviations from water quality targets.     

Factors Affecting Sales at Farmers' Markets: An Iowa Study

The 180 farmers' markets operating in a range of urban to rural communities in Iowa provide a useful setting to evaluate factors affecting sales at these markets. Higher average sales at markets tended to be associated with urban and higher income areas. Only 30% of vendors reported sales greater than $5,000, mostly in the produce category.     

2000年滇池流域水污染的综合治理

2000年滇池流域水污染综合治理实施了一系列工程,取得了一定成效。但由于滇池流域自身水环境问题,以及治理过程中出现了对其治理的复杂性与长期性认识不足、重视有形工程、忽视管理、治理资金渠道单一、“多龙治水”协调机制差等问题,针对存在的问题,本文剖析其原因,并提出若干建议及对策。     

Modeling Starting Point Bias as Unobserved Heterogeneity in Contingent Valuation Surveys: An Application to Air Pollution

Up to now, the starting point bias has generally been considered to be a homogeneous phenomenon. In this article, we treat anchoring as an unobserved heterogeneous phenomenon. Our contribution is twofold. First, we show analytically and by way of simulations that assuming homogeneous anchoring can be hazardous and lead to misspecifications. Second, we propose an econometric model that starts with a dichotomous question and then uses an open-ended question. We finally apply our model to a contingent valuation survey on air quality. Our results suggest that how anchoring is modeled in empirical studies deserves more attention.     

Watershed management in an urban setting: process, scale and administration

Efforts in post-industrial countries to refine environment and planning administration in the face of unprecedented urban growth have important implications for ecological systems and human quality of life. This paper uses the case of an urban riparian corridor in South East Queensland, Australia to contribute to understandings of interactions between land use planning processes, watershed management initiatives and broader administrative structures in urban and rapidly urbanising settings. In particular it examines the understudied application of watershed management to an urban setting. Analysis of changes to the structure and function of urban riparian corridor management over time show that changes have occurred as a result of broader policy and institutional change in three distinct phases: top-down watershed management policy (1996-2000), regional natural resource and population growth management policy (2001-2005) and the recent re-emergence of local government as the dominant actor in a multilevel networked context (2006-2008). Trends toward regional scale approaches and increased urban planning initiatives have tended to concentrate responsibilities for urban environmental management with local government. This is in contrast to most rural natural resource management experience, and highlights the importance of meta-governance frameworks in ensuring the enduring applicability of the watershed management model to urban and rapidly urbanising catchments.     

农民施肥行为及农业面源污染研究

本文旨在通过采用统计分析和构建计量经济模型的方法分析农户的施肥行为，寻找到在农户层面降低农业面源污染的有效途径。研究结果表明，非农就业会对化肥施用水平产生一定的促进作用；而有机肥与化肥在农业生产中的替代关系并不十分明显；相反，农业技术培训与农户化肥的施用水平呈正相关关系：化肥施用水平在不同地区之间有较大差异。     

基于演化博弈的地方政府水污染规制策略分析

党的十八大五中全会将生态文明建设作为重要发展战略,但生态文明建设的重点"水污染治理"依旧处于困境之中。水污染治理的难点在于水污染规制策略执行人——地方政府与其他利益主体理性目标的差异。基于地方政府间博弈竞争的分析框架,引入中央政府约束和激励机制,分析地方政府间对于水污染规制博弈策略的动态演进行为。研究结果表明,水污染的外部性不会影响地方政府间博弈策略;政府可以通过提高水污染指标在地方政府政绩考核权重,降低水污染规制成本,减弱企业利润对地方政府支付水平的影响程度,构建约束和激励机制来防止地方政府间的博弈陷入"囚徒困境",促使地方政府水污染规制策略的高效执行。     

An Economic Analysis of Localized Pollution: Rendering Emissions in a Residential Setting

The contingent value method is employed to estimate economic damages to households resulting from rendering plant emissions in a small town. Household willingness to accept (WTA) and willingness to pay (WTP) are estimated individually and in aggregate. The influence of household characteristics on WTP and WTA is examined via regression models. The perception of health risk is an important determinant of household valuation, while income appears insignificant. Both WTA and WTP results indicate that a potential Pareto-improvement is possible with the incorporation of current abatement technology La méthode des valeurs contingentes est utilisée pour évaluer les dommages économiques causés aux ménages par les émissions d'une usine d'équarrissage dans une petite localité. Les valeurs WTA et WTP des ménages sont estimées séparément puis sous formes agrégee. L'influence des caractères du ménage sur la WTP et la WTA est examinée au moyen de modèles de régression. La perception du risque pour la santé est un déterminant important de la valeur accordée par le ménage, alors que le niveau de revenu n'aurait qu'une influence négligeable. Les valeurs WTA et WTP obtenues laissent voir qu'un critère Pareto serait possible avec la mise en place des techniques modernes antipollution     

Targeting Conservation Investments in Heterogeneous Landscapes: A Distance-Function Approach and Application to Watershed Management

To achieve an environmental objective at least cost, decision makers must integrate information about spatially variable biophysical and economic conditions. Although the biophysical attributes that contribute to an environmental outcome are often known, the way in which these attributes interact to produce the outcome is often unknown. We introduce a nonparametric conservation targeting approach that relies on distance functions to cost-efficiently allocate conservation funds. We apply the approach empirically to the case of conservation contracting for water-quality objectives. The contract portfolios derived from the application have many desirable properties, including intuitive appeal and robust performance across plausible parametric scoring measures.     

The future of agriculture and society in Iowa: four scenarios

Iowa is a leader in crop and livestock production, but its high productivity has had concomitant negative environmental and societal impacts and large requirements for fossil-fuel-derived inputs. Maintaining agricultural productivity, economic prosperity and environmental integrity will become ever more challenging as the global demand for agricultural products increases and the resources needed become increasingly limited. Here we present four scenarios for Iowa in 2100, based on combinations of differing goals for the economy and differing energy availability. In scenarios focused on high material throughput, environmental degradation and social unrest will increase. In scenarios with a focus on human and environmental welfare, environmental damage will be ameliorated and societal happiness will increase. Movement towards a society focused on human and environmental welfare will require changes in the goals of the economy, whereas no major changes will be needed to maintain focus on high throughput. When energy sources are readily available and inexpensive, the goals of the economy will be more easily met, whereas energy limitations will restrict the options available to agriculture and society. Our scenarios can be used as tools to inform people about choices that must be made to reach more desirable futures for Iowa and similar agricultural regions.     

抵押物处置与农房抵押贷款困境：基于演化博弈的分析

研究目的:分析农民住房财产权抵押(简称农房抵押)贷款困境的主要原因以及抵押物处置对农房抵押贷款行为的影响机理。研究方法:演化博弈论。研究结果:农房抵押贷款发展面临困境的关键在于金融机构惜贷,而抵押物处置难是激发金融机构惜贷的重要原因,但是降低抵押物处置难度只是推动农房抵押贷款发展的必要而非充分条件。研究结论:要促进农房抵押贷款发展,除了必须降低抵押物处置难度外,还需要构建完善的农房抵押贷款制度体系。     

Formal versus Informal System to Mitigate Non-point Source Pollution: An Experimental Investigation

Water pollution caused by aquaculture or agricultural activities negatively affects both the activity and downstream areas. A number of other upstream-downstream problems (e.g. water use, industrial/municipal water source pollution, salinity zoning problems) are examples of similar negative externalities. Non-point source pollution, which is either prohibitively costly or impossible to observe, is more feasible to identify, and hence mitigate at the aggregate level. We study experimentally the efficacy of two possible management systems: a centralised external, formal government-led monitoring and control system; a self-governing communication and informal system, both designed to manage shrimp farming, which generates a non-point source pollution with upstream-downstream externalities. Our results suggest that local communication and control outperforms the external monitoring and certification agency. These results, in conjunction with other relevant research, suggest that informal regulation and self-governance among shrimp farmers can be highly successful in tackling the pollution problem.     

Marketing Specialty Hogs: A Comparative Analysis of Two Firms from Iowa

We study business organization and coordination of specialty-market hog production using a comparative analysis of two Iowa firms marketing niche pork. We analyze each firm's management of five key organizational challenges: planning and logistics, quality assurance, process verification and management of "credence attributes," business structure, and profit sharing. Although each firm is engaged in essentially the same activity, there are substantial differences across the two firms in the way production and marketing are coordinated. These differences are partly explained by the relative size and age of each firm, but also by the formal organizational separation between marketing and production activities in one of the firms.     

Welfare Impacts of Alternative Public Policies for Agricultural Pollution Control in an Open Economy: A General Equilibrium Framework

A general equilibrium approach is used to evaluate the welfare impacts of alternative policies for reducing agricultural pollution in an open economy with preexisting distortions caused by income taxes and agricultural subsidies. The policies examined here include the removal of distortionary agricultural subsidies. We find that even though these distortions are small compared to others in the economy, removing them and imposing nitrogen reduction subsidies and/or output taxes can enhance welfare and reduce nitrogen pollution; thereby leading to a substantial double dividend. The relative efficiency of the alternative policies examined here depends on the level of the nitrogen reduction target.     

黄河兰州段水质污染状况分析

黄河穿兰州城而过，为城市的发展提供了丰富的水源。同时，大量的污染物排放到河中，造成不同河段的污染。本文以1991—2000年的统计资料，主要从化学和生物两个角度来分析黄河兰州段的水质污染状况，并运用SPSS统计软件分析了两者的相关关系。最后得出黄河兰州段以生物、有机污染为主。就此提出减少废水排放量(尤其是工业废水)是控制黄河兰州段水质的关键。     

An interactive land use transition agent-based model (ILUTABM): Endogenizing human-environment interactions in the Western Missisquoi Watershed

Forest Transition Theory (FTT) suggests that reforestation may follow deforestation as a result of and interplay between changing social, economic and ecological conditions. We develop a simplistic but empirically data driven land use transition agent-based modeling platform, interactive land use transition agent-based model (ILUTABM), that is able to reproduce the observed land use patterns and link the forest transition to parcel-level heuristic-based land use decisions and ecosystem service (ES). The ILUTABM endogenously links landowners’ land use decisions with ecosystem services (ES) provided by the lands by treating both lands and landowners as interacting agents. The ILUTABM simulates both the land use changes resulting from farmers’ decision behaviors as well as the recursive effects of changing land uses on farmers’ decision behaviors. The ILUTABM is calibrated and validated at 30 m × 30 m spatial resolution using National Land Cover Data (NLCD) 1992, 2001 and 2006 across the western Missisquoi watershed, which is located in the north-eastern US with an estimated area of 283 square kilometers and 312 farmers farming on 16% of the total Missisquoi watershed area. This study hypothesizes that farmers’ land use decisions are made primarily based on their summed expected utilities and that impacts of exogenous socio-economic factors, such as natural disasters, public policies and institutional/social reforms, on farmers’ expected utilities can significantly influence the land use transitions between agricultural and forested lands. Monte Carlo experiments under six various socio-economic conditions combined with different ES valuation schemes are used to assess the sensitivities of the ILUTABM. Goodness-of-fit measures confirm that the ILUTABM is able to reproduce 62% of the observed land use transitions. However, the spatial patterns of the observed land used transitions are more clustered than the simulated counterparts. We find that, when farmers value food provisioning Ecosystem Services (ES) more than other ES (e.g., soil and water regulation), deforestation is observed. However, when farmers value less food provisioning than other ES or they value food provisioning and other ES equally, the forest transition is observed. The ILUTABM advances the Forest Transition Theory (FTT) framework by endogenizing the interactions of socio-ecological feedbacks and socio-economic factors in a generalizable model that can be calibrated with empirical data.     

Testing for Dynamic Misspecification of Input Demand Functions: An Application to Canadian Agriculture

Previous applications of the inter-temporal quadratic adjustment cost model in agriculture have failed to consider information gained from pre-testing in choosing an appropriate specification for dynamic demand of quasi-fixed inputs. A test strategy is outlined taking account of this information in order to consistently estimate adjustment cost and discount rate parameters. Canadian agricultural data are used in the empirical analysis. Test results suggest that the intertemporal quadratic adjustment cost model is inappropriate for modeling dynamic demand for land, labor and machinery.     

模拟退火算法在土地利用总体规划中的应用

土地利用总体规划的核心就是土地利用结构的配置,在土地利用结构配置的各种方法中,模型法是一种较好的方法,提出了基于模拟退火算法模型的土地利用总体规划方法.介绍了模拟退火算法的模型和关键技术,并以铜山县为例进行了模型设计,把土地类型分为十大类,把经济效益最大化作为主导规划目标,将其它效益作为约束条件.根据设计的模型编程实现,得到了预期的结果,结果表明模拟退火算法是一种土地利用总体规划的有用的、有潜力的优化方法.