Observed oil and gas field size distributions: A consequence of the discovery process and prices of oil and gas

If observed oil and gas field size distributions are obtained by random samplings, the fitted distributions should approximate that of the parent population of oil and gas fields. However, empirical evidence strongly suggests that larger fields tend to be discovered earlier in the discovery process than they would be by random sampling. Economic factors also can limit the number of small fields that are developed and reported. This paper examines observed size distributions in state and federal waters of offshore Texas. Results of the analysis demonstrate how the shape of the observable size distributions change with significant hydrocarbon price changes. Comparison of state and federal observed size distributions in the offshore area shows how production cost differences also affect the shape of the observed size distribution. Methods for modifying the discovery rate estimation procedures when economic factors significantly affect the discovery sequence are presented. A primary conclusion of the analysis is that, because hydrocarbon price changes can significantly affect the observed discovery size distribution, one should not be confident about inferring the form and specific parameters of the parent field size distribution from the observed distributions.This paper was presented at Emerging Concepts, MGUS-87 Conference, Redwood City, California, 13–15 April 1987.     

Vehicle tax policies and new passenger car CO2 performance in EU member states

This article explores the causes for differences in the average CO₂ emissions intensity of the new passenger car (NPC) fleet in member states (MS) across Europe. Although EU policies mitigating CO₂ emissions from NPCs have been in place since 1999, MS strongly diverge in the absolute amount and relative change in emissions over the last decade. The authors employ a qualitative approach to analyse the factors, in particular national vehicle taxes, contributing to this divergence and the relative contribution of national and European policies in reducing national CO₂ emissions from NPCs. The analysis shows that there has been a significant reduction in CO₂ emissions intensity of NPCs since 2007 across most MS, compared with the six years previous to that date. This would indicate that EU-wide policies, such as the CO₂ vehicles regulation, along with the economic recession in 2008, have influenced national NPC CO₂ emissions. Generally, countries with CO₂-differentiated vehicle taxes are observed as more likely to have achieved greater reductions in CO₂ emissions. However, over the same period there have been many confounding factors, such as economic instability in the EU, that also influence NPC emissions. Using more detailed case study analyses of six countries, the authors find that there is scope for well-designed national vehicle tax policies to drive NPC emissions down further than the EU average. In countries with the highest success rate, such as the Netherlands, the design of the vehicle tax, as part of a well-aligned policy package, has been very important in delivering the biggest reductions in CO₂ emissions from NPCs.

POLICY RELEVANCE

The transport sector continues to be an intractable source of CO₂ emissions. Governments around the world are seeking effective policies to deal with the increase in passenger car CO₂ emissions appropriate to their own circumstances. This article examines the experience of EU MS with CO₂-differentiated vehicle taxes in reducing CO₂ emissions in the context of other national and international contributing factors. It should therefore both be useful to policy makers and contribute to climate policy research in general.     

灾害防御工程的经济效益评价原理及方法——以水坝震害防御工程为例

根据价值工程理论和成本-效益理论,在作者提出的防灾工程功能函数、成本函数、价值函数、效益函数等灾害经济学基本函数及数学模型的基础上,结合地质灾害防御工程实例,探讨了防灾工程经济效益的评价原理及方法。     

Economic aspects of pad construction costs on heap leach projects

Summary Pad construction costs can affect the overall economics of heap leach projects. Costs for single- and double-lined pads, using various designs, are listed for a typical small and large project. Double-lined pads are now frequently required by regulatory agencies. Unless such designs significantly reduce the risk of site-specific contamination, the extra costs cannot be justified from an economical viewpoint. Specific attention is given to the short project life (typically five years) of heap leach projects. A few numerical examples are presented to demonstrate the overall impact of these costs on economic parameters.     

新制度经济学视角下高校周边商业街分异研究——以湖南师范大学和湖南大学本部校区为例

高校扩招带来了其周边商业街的蓬勃发展,已有研究从不同角度对其展开论述,新制度经济学的发展与完善为理解高校周边商业街的分异提供了新的可能性。以湖南师范大学和湖南大学本部校区的4条商业街为例,从新制度经济学的角度解释高校周边商业街分异现象,以期丰富新制度经济学视角微观实证研究的内容。实地调研发现,制度对高校周边商业街的分异具有重要作用,正式制度对不同主体的约束作用不同,进而形成一系列非正式制度,从而共同维系了商业街的发展。最后,从制度的角度对高校周边商业街的发展提出了建议。     

A place-based approach to payments for ecosystem services

Payment for Ecosystem Services (PES) schemes are proliferating but are challenged by insufficient attention to spatial and temporal inter-dependencies, interactions between different ecosystems and their services, and the need for multi-level governance. To address these challenges, this paper develops a place-based approach to the development and implementation of PES schemes that incorporates multi-level governance, bundling or layering of services across multiple scales, and shared values for ecosystem services. The approach is evaluated and illustrated using case study research to develop an explicitly place-based PES scheme, the Peatland Code, owned and managed by the International Union for the Conservation of Nature’s UK Peatland Programme and designed to pay for restoration of peatland habitats. Buyers preferred bundled schemes with premium pricing of a primary service, contrasting with sellers’ preferences for quantifying and marketing services separately in a layered scheme. There was limited awareness among key business sectors of dependencies on ecosystem services, or the risks and opportunities arising from their management. Companies with financial links to peatlands or a strong environmental sustainability focus were interested in the scheme, particularly in relation to climate regulation, water quality, biodiversity and flood risk mitigation benefits. Visitors were most interested in donating to projects that benefited wildlife and were willing to donate around £2 on-site during a visit. Sellers agreed a deliberated fair price per tonne of CO₂ equivalent from £11.18 to £15.65 across four sites in Scotland, with this range primarily driven by spatial variation in habitat degradation. In the Peak District, perceived declines in sheep and grouse productivity arising from ditch blocking led to substantially higher prices, but in other regions ditch blocking was viewed more positively. The Peatland Code was developed in close collaboration with stakeholders at catchment, landscape and national scales, enabling multi-level governance of the management and delivery of ecosystem services across these scales. Place-based PES schemes can mitigate negative trade-offs between ecosystem services, more effectively include cultural ecosystem services and engage with and empower diverse stakeholders in scheme design and governance.     

Forecasting rates of hydrocarbon discoveries in a changing economic environment

A method is presented for the estimation of undiscovered oil and gas resources in partially explored areas where economic truncation has caused some discoveries to go unreported; therefore distorting the relationship between the observed discovery size distribution and the parent or ultimate field size distribution. The method is applied to the UK's northern and central North Sea provinces. A discovery process model is developed to estimate the number and size distribution of undiscovered fields in this area as of 1983. The model is also used to forecast the rate at which fields will be discovered in the future. The appraisal and forecasts pertain to fields in size classes as small as 24 million barrels of oil equivalent (BOE). Estimated undiscovered hydrocarbon resources of 11.79 billion BOE are expected to be contained in 170 remaining fields. Over the first 500 wildcat wells after 1 January 1983, the discovery rate in this areas is expected to decline by 60% from 15 million BOE per wildcat well to six million BOE per wildcat well.     

资源增殖型渔业的理论探讨与对策建议

以科学发展观为指导,界定了资源增殖型渔业的内涵和外延;在评价以往资源增殖措施绩效的基础上,依据经济学和行为科学理论,运用“故障树分析法”、“力场分析法”等,从制度的缺陷和缺位,解释了渔业资源衰退的原因;并从观念转变、措施改进、制度创新、利益机制建立等方面提出了对策建议.