The Value of Badger Populations and Control of Tuberculosis in Cattle in England and Wales: A Note

This note reports on the results of a choice experiment survey of 400 people in England and Wales, conducted to estimate the value that society places on changes to the size of the badger population. The study was undertaken in the context of the possible need to reduce the badger population by culling to help control bovine tuberculosis in cattle. The study found that people were concerned about the problem of bovine tuberculosis in cattle, which was reflected in their willingness to pay to control the disease, and gave a relatively low value to changes in the size of the badger population (within limits). However, people did not like the idea of a policy that intentionally killed large numbers of badgers and had a relatively very high willingness to pay not to have such a policy.     

Ozone and Wheat Farming in Alberta: A Micro-study of the Effects of Environmental Change

Alberta's Clean Air Act of 1971 sets out maximum allowable levels for ozone concentrations in Alberta. Evidence shows that these standards for ambient ozone concentrations are often exceeded. As biological studies reveal, one of the consequences of exposure to ozone can be reduced yields for agricultural crops. Wheat, a major crop in Alberta, is one crop that has been shown to be sensitive to ozone. Biological studies alone, however, cannot capture the responses of farmers to deteriorating air quality. The profit-maximizing response, which can include changes in both output levels and input mixes, and the cost-minimizing response, which involves changes in input mixes, can be captured by estimating a variable profit and a variable cost function. The application of duality theory to the results from estimation of variable profit and cost functions allows researchers to study the impact of changing ozone levels on profits and costs as well as on the selection of factor input mixes and wheat output levels. In our study of wheat farming in Alberta, we find that, while the specific responses of farmers in terms of their input mix and output supply appear to vary across farms, there are significant decreases in profits and increases in costs as ozone concentrations rise. La Alberta Clean Air Act de 1971 fixe les niveaux acceptables maximums d'ozone en Alberta. Il appert que ces concentrations ambientales sont souvent dépassées. Comme le révèelent les études biologiques, une des conséquences de l'exposition à l'ozone peut être une diminution du rendement des cultures. Culture d'importance en Alberta, le blé s'est montré sensible à l'ozone. Toutefois, les études biologiques à elles seules ne peuvent saisir toutes les réactions des agriculteurs à la dégradation de la qualité de I'air. La réaction axée sur la maximisation des profits, laquelle peut inclure des changements à la fois dans le niveau de production et dans la composition des intrants, et la reponse axee sur la minimisation des coûts qui, elle, ne porte que sur la composition des intrants peuvent être saisies par une fonction à profit variable et par unefonction à coût variable. L'estimation combinée de ces fonctions permet aux chercheurs d'examiner les incidences des changements de la concentration d'ozone sur les bénéfices et sur les coûts, ainsi que sur le choix des combinaisons d'intrants utilisées et des niveaux de rendement du blé escomptés. Dans le cadre de notre étude sur les cultures du blé en Alberta, nous constatons que si la composition des intrants et les niveaux de production semblent varier d'une ferme à l'autre, l'accroissement des concentrations d'ozone dans l'atmosphére s'accompagne de chutes significatives des bénefices et d'accroissements significatifs des coûts.     

浅析臭氧对小麦呕吐毒素的抑制

中央储备粮临沂直属库有限公司沂水分公司2号仓小麦呕吐毒素在950 mg·kg-1左右,接近卫生指标,利用臭氧机对全仓小麦进行杀菌,利用内环流作为辅助动力,处理两周,该仓小麦的呕吐毒素含量达到550 mg·kg-1左右,有效控制了害虫、霉菌的生命活动,延缓了粮食品质的变化,减少化学药剂熏蒸,实现绿色储粮,达到了安全、经济...     

A Statistical Analysis of Wheat Price Fluctuations in England: 1685–1850

For some commodities and time periods, the analysis of price fluctuations must necessarily rely on the existence of price data alone. A theory applicable in such circumstances is outlined for commodities that are storable, traded in open markets and subject to net supply shocks which are heterogeneously distributed across the months of the year. Market prices are predicted to vary autoregressively except at times when wheat stocks become negligible and observed market prices exceed threshold prices (which may themselves differ across months). The model is applied to a monthly time series of wheat prices for southern England from 1685 to 1850. The autoregressive parameter and the threshold prices are estimated, substantial empirical support being found for the models tested. Historical events from the late seventeenth century through to the continental wars in the late eighteenth and early nineteenth centuries are used to illustrate the mechanisms underlying the theory.     

A Note on the Profitability of Wheat-ethanol-feedlot Production in Alberta

A risk analysis of the economics of alternative wheat supplies to a small ethanol-beef feedlot facility was conducted, based on historical data from an 18-year period (1978–96). Alternatives simulated were Black, Dark Brown and Brown soil zone locations in Alberta growing either Hard Red Spring (HRS) wheat, Canadian Prairie Spring (CPS) wheat or irrigated Soft White (SWW) wheat to supply a 10 ML per year ethanol plant. The plant would use the coproduct of wet distillers grains in the finishing of approximately 14,000 steer calves per year. Three valuation scenarios were considered: selling ethanol at its market price, inclusion of current Alberta tax incentive levels for ethanol sale, and sale of wheat to the Canadian Wheat Board as opposed to sale to an ethanol plant. Ethanol facility and total net revenues were highest for the CPS-Dark Brown soil scenario due to its relatively high ethanol yields per tonne of feedstock, and high grain yields per hectare. An integrated feedstock-ethanol-livestock operation selling ethanol at current subsidy (tax incentives) levels will lose money approximately half to two-thirds of the time over the long run. Without subsidies, an integrated facility would lose money two-thirds to three-quarters of the time. Nous avons réalisé, à partir de données recueillies durant une période de 18 ans (1978 à 1996), une analyse de risque des aspects économiques de diverses provenances de blé pour une petite exploitation éthanol-parc d'engraissement. Les options simulées consistaient en emplacements situés dans les zones de sols noirs, brunfoncé et bruns de I'Alberta, produisant soil du blé roux vitreux deprintemps (BRVP), du blé de printemps des Prairies canadiennes (BPPC) ou du blé blanc tendre (BBT) sous irrigation pour alimenter un atelier d'éthanol d'un volume de fabrication de 10 millions de litres par année. L'atelier hypothétique utiliserait le co-produit des drêches de distillerie humides pour engraisser quelque 14 OOOjeunes bouvillons par année. Trois scénarios de valorisation étaient envisagés: vente de I'éthanol au prix de marché, inclusion des incitatifs fiscaux actuels de I'Alberta pour la vente de I'éthanol et vente du bléà la Commission canadienne du blé par opposition à la vente à un atelier de production d'éthanol. Les revenus nets tirés de I'atelieret les revenus nets totaux les plus élevés de l'exploitation étaient obtenus dans le scénario BPPC-sol brunfoncé en raison des rendements d'éthanol relativement élevés par tonne de blé et des bons rendements grainiers par hectare obtenus dans cette combinaison. Selon les résultats obtenus, un atelier intégré blé-éthanol-parc d'engraissement écoulant son éthanol au niveau de subvention actuel (incitatifs fiscaux), perdrait de I'argen d'environ la moitié aux deux tiers du temps. Sans ces subventions, il ne rentrerait dans ses dépenses qu'unefois sur trois ou unefois sur quatre seulement.     

Implications of CAP reform for land management and runoff control in England and Wales

WTO negotiations, as well as problems associated with intensive agriculture, such as overproduction, dependency on high levels of subsidies, diffuse pollution, soil degradation and loss of wildlife, have led to a reconsideration of agricultural policies in Europe. In April 2005, the new common agricultural policy (CAP)-reform came into force in the United Kingdom, decoupling financial support to farmers from agricultural production. Farm income support payments are now linked to compliance with standards (cross-compliance rules) which protect the environment, animal health and welfare. In the light of these policy changes, semi-structured interviews were carried out with 36 farmers in five catchments in the UK to explore interrelationships between CAP-reform, agricultural land management and runoff-related problems. Results from three catchments are specifically highlighted because of their relevance for soil policy.The CAP-reform appears to facilitate and accelerate changes in the agricultural sector that were already happening. It is likely that upland livestock farms will extensify further, which will reduce environmental burdens such as diffuse pollution, soil compaction and runoff. The uptake of agri-environment schemes by individual farmers has increased since the CAP-reform. However, additional impacts are limited as there is a tendency among participants to enter these schemes based on existing features and practices.Although most farmers interviewed for this study appear to recognise the need to reduce soil erosion and diffuse pollution, they are less convinced they should be held responsible for controlling storm-water runoff from farmland that might contribute to flooding downstream. However, there are opportunities to achieve several objectives simultaneously, including improved soil management, runoff control and reduced pollution. Lessons can be learned from farmers’ opinions about CAP-reform, from successful interventions that aimed to reduce soil erosion and diffuse pollution, and also from failures. Recommendations are made for improvements to the current agri-environment schemes and to promote land management practices with less environmental burden.     

Evaluating participation in WFD river basin management in England and Wales: Processes,communities, outputs and outcomes

Participatory environmental governance is increasing worldwide. One area where such governance forms are apparent is in the management of water resources. For example, in the European Union the Water Framework Directive mandates several forms of involvement via its legal obligations. Under the Directive, implementing agencies should provide information on river basin management planning to the public, consult citizens and stakeholders during planning and actively involve interested parties in the plan process. Yet questions arise over the success of participatory processes on the ground in EU member states. In this study, participation was therefore evaluated in WFD river basin planning in England and Wales using process, community, output and outcome-related indicators. Research was conducted through extensive quantitative and qualitative data collection over a long temporal scale within case analyses of the Anglian, Humber and South West river basin districts. Results suggest that while the first phase of river basin management largely met legal requirements, the actual success of participatory water governance was mixed. On this basis, recommendations are made for enhancing participation in future river basin planning through national and EU policy.     

中国小麦生产的技术进步模式研究

本文利用1990-2004年中国小麦生产的省区面板数据，估算这个时期的年均技术进步率，并利用特定的生产函数E—S模型测算小麦生产生物化学型技术进步指数和机械型技术进步指数，对比全国及小麦主产省份土地生产率和劳动生产率指数的变化。结果表明，该时期小麦生产呈现机械型技术进步为主的发展模式；技术进步和物质投入的增加是我国小麦单产持续增长的两大因素。未来为保证小麦单产的持续增长，必须加大对小麦生物化学型技术研发的投入，突破技术限制，为未来提供技术储备。     

Forces and Relations of Production in Early Medieval England

The economy of post-Roman Britain entered a phase of abatement in which pastoralism played an important part. Common pasture and access to it underlay small regions within which the form of dominance practised by an emerging elite was neither antique nor feudal but akin to that of chieftains over clans. The mid-Saxon emphasis on arable farming, which demanded heavier and more concentrated inputs of labour and capital, led to a more direct appropriation of peasant surplus and labour, the basis of the feudal mode of production.     

An Old Problem Revisited—and Solved: Upton and Dalton's Linear Production Response: A Note

This note presents a robust method for estimating response surfaces that consist of linear response regimes and a linear plateau. The linear response‐and‐plateau model has fascinated production scientists since von Liebig (1855) and, as Upton and Dalton indicated, some years ago in this Journal the response‐and‐plateau model seems to fit the data in many empirical studies. The estimation algorithm evolves from Bayesian implementation of a switching‐regression (finite mixtures) model and demonstrates routine application of Gibbs sampling and data augmentation—techniques that are now in widespread application in other disciplines.     

Modelling the transportation of primary aggregates in England and Wales: Exploring initiatives to reduce CO2 emissions

Millions of tonnes of aggregates are transported across England and Wales each year, which causes constant concerns in regard to CO₂ emissions. Much of that concern arises out of the long journeys from quarries to construction sites, and the fact that the main mode of transfer is by road. The aim of this paper is to describe the construction of a spatial decision support system (SDSS) to examine the impacts of scenarios to reduce the level of CO₂ emissions. The SDSS is made up of a GIS containing a set of spatial models (including a spatial interaction model and a microsimulation model) underpinned by a detailed transport network of road and rail routes across England and Wales. The spatial interaction models are first calibrated to reproduce the existing set of flows of aggregates between quarries and local authority districts. The distance decay component is the travel distance equivalent across the road and rail networks. Based on these flows, linear models can be set up to estimate the amount of CO₂ emissions associated with the existing set of flows. Then a series of what-if scenarios are set up which look at how changes in any part of the geography of production, the level of demand in certain areas or the transport process will impact the CO₂ emissions. The paper demonstrates the capability of the SDSS in responding to the various spatial policies applied in different stages of the supply chain of the aggregates markets.     

我国小麦生产效率的DEA分析

本文利用我国小麦生产成本收益数据,分析了20世纪90年代以来我国小麦生产全要素生产率及其构成的变化趋势及特点,从而探讨我国小麦生产效率下降的原因及提高的途径。