Hydro-economic river basin modelling: The application of a holistic surface-groundwater model to assess opportunity costs of water use in Spain

Combined hydro-economic models of river basins are fundamental tools for assessing management and infrastructure strategies to improve the economic efficiency of water use in a context of competition over scarce water resources. Integrated hydro-economic models have to be capable to properly reproduce the physical behavior of the system, with a realistic representation of the different surface and groundwater resources, including their interaction, and the spatial and temporal variability of resource availability. On the other hand, such models must incorporate the value of water for different urban, agricultural and industrial uses and users. Economic values for water use are defined according to the marginal residual value of water for production (for agricultural and industrial uses) or the aggregated willingness-to-pay (WTP) for urban supply and other final water uses. In this paper, we present a systematic approach to estimate the marginal economic value of surface and groundwater resources at different locations within a complex water resources system. Based on a holistic conjunctive optimization model applied to the Adra river system in Spain we asses the total and marginal opportunity costs of capacity and operation constraints, including the opportunity cost of imposing environmental constraints on water use as foreseen in future Spanish water policy following the implementation of the European Water Framework Directive. The resulting opportunity costs provide important information to water managers about economic inefficiencies of current water allocation policy or infrastructure design, and about the resource opportunity costs to be considered in the design of efficient pricing policies in regions with water scarcity issues.     

数字经济领域的研究述评、热点主题与新兴趋势——基于文献计量学的分析

为把握数字经济研究脉络、热点和趋势,基于Web of Science核心数据库来源文献,利用CiteSpace和VOSviewer两种文献计量分析工具,对2009年以来数字经济文献进行计量分析。研究结果明确了数字经济年度发表趋势和领域类别、最具影响力和生产力的作者、机构、国家和期刊,数字经济相关研究在经历十几年的停滞后,目前处在快速增长期,研究学科集中在管理、环境科学、通信、环境研究和商业等领域,美国、英国和中国是重要的数字经济研究中心,国家之间和国际研究机构之间的研究合作有待加强。数字经济研究的突显主题经历了三个显著变化的发展阶段,呈现技术-产业-制度不断发展的演化脉络。数字经济研究热点集中在数字化、社会媒介、共享经济和循环经济等四个方面。综合关键词聚类结果和技术经济范式理论,从技术系统视角数字经济新兴趋势包括数字技术、智能资产和数字平台等;从产业系统视角包括商业模式、价值创造、循环经济、共享经济和零工经济等;从制度系统视角包括平台资本和政治经济等。最后是研究结论和展望。     

国外新经济理论的研究进展

随着技术变革的深入,新兴技术对经济发展产生的影响更为深入,产生了以知识和创新为核心的新经济,对传统经济理论提出了挑战。特别是金融危机之后,全球经济发展方式发生变革,对新经济理论与方法的研究具有重要现实意义。文章对国外新经济的产生与发展相关理论进行系统梳理与分析、从技术变革与新经济的关系、新经济的理论基础、新经济形态下经济发展方式的变化及其新经济理论的应用领域等方面剖析了国外新经济理论的研究进展,提出未来新经济领域可围绕国家创新体系的战略定位研究、技术变革发展方向的预测方法、技术变革推动经济增长与社会进步的过程分析、新经济理论框架对产业结构影响以及新经济背景对企业发展的影响等方面展开。     

Assessment of regional trade and virtual water flows in China

The success of China's economic development has left deep marks on resource availability and quality. Some regions in China are relatively poor with regards to water resources. This problem is exacerbated by economic growth. Flourishing trade activities on both domestic and international levels have resulted in significant amounts of water withdrawal and water pollution. Hence the goal of this paper is to evaluate the current inter-regional trade structure and its effects on water consumption and pollution via ‘virtual water flows’. Virtual water is the water embedded in products and used in the whole production chain, and that is traded between regions or exported to other countries. For this assessment of trade flows and effects on water resources, we have developed an extended regional input-output model for eight hydro-economic regions in China to account for virtual water flows between North and South China. The findings show that the current trade structure in China is not very favorable with regards to water resource allocation and efficiency. North China as a water scarce region virtually exports about 5% of its total available freshwater resources while accepting large amounts of wastewater for other regions' consumption. By contrast, South China a region with abundant water resources is virtually importing water from other regions while their imports are creating waste water polluting other regions' hydro-ecosystems.     

Comparing approaches to valuing sectoral net investments

In the literature of comprehensive national accounts, national net investments are used to indicate dynamic welfare improvement in an economy. A well-known approach associates national net investments with the shadow value of change in stock of capital assets in an economy. Following this capital stock approach, sectoral net investments can be defined as the shadow value of change in stock of capital assets owned by a sector in an economy. An alternative approach is based on future commodity flows to a sector. This commodity flow approach associates sectoral net investments with the present value of changes in future commodity flows to a sector. In the present paper, I compare these two approaches and prove that they coincide with each other only if the future commodity flows to the sector can be attributed to current stock of capital assets in the sector alone. In empirical studies, commodity flow approach can be a better alternative if the purpose is to estimate the contributions to national net investments of a recipient of future cash flows.     

From Demand Equations to Two Regimes: The Theoretical Development of Export Models

Over the last fifty years or so, a great deal of attention has been paid to the estimation of time-series models of foreign trade flows – especially those relating to the volume of trade in imperfectly substitutable goods between one country and the rest of the world. In this time, the models employed have evolved from relatively simple demand equations through to more complex simultaneous-equation and two-regime approaches. The aim of this paper is to survey the developments that have been made and suggest some directions for future research by highlighting the weaknesses of the approaches currently available.     

实际商业周期:理论、检验与争议

围绕实际商业周期所展开的研究涉及经济学研究的基本方法和经济学家们对经济社会运行的基本认识。与此同时,它也反映了经济学两大流派,即凯恩斯学派和新古典学派之问的争论。本文试图从 RBC 理论的产生背景说起,系统地为读者介绍 RBC 的理论体系以及求解和检验 RBC 模型时所使用的一些技术。与此同时,我们也将揭示 RBC 研究所面临的问题和引发的争论,并在此基础上指出未来 RBC 和宏观经济学理论研究可能的发展方向。     

Water valuation at basin scale with application to western India

A parsimonious hydro-economic model for a data scarce dryland area is presented. It features a basin level decentralized water allocation mechanism which is adapted to incorporate sustainable water use and to deal with the externalities from upstream-downstream linkages. We formulate the profit maximization problem of various agents in a basin, each identifying a sub-basin, who operate within the boundaries of a spatially explicit model that describes the dominant hydrological processes. We address issues of non-convexities and non-steady state conditions and elicit the dependence of a decentralized water allocation on geophysical properties of the basin. In particular, the approach describes how the competition between the drying and drainage functions of sub-basins in dryland areas manifests itself in the optimal valuation of water. The application to an area of over 500,000 km² and 34 sub-basins in western India indicates that intra-basin cooperation could be beneficial; valuation of inter basin flows as a percentage of respective sub-basin income is on an average around 30% when each sub-basin includes downstream valuation as well.     

Valuing water quality improvements in the United States using meta-analysis: Is the glass half-full or half-empty for national policy analysis?

The literature estimating the economic value for water quality changes has grown considerably over the last 30 years, resulting in an expanded pool of information potentially available to support national and regional policy analysis. Using 131 willingness to pay estimates from 18 studies that use a similar definition of water quality, we performed a meta-regression analysis and found mixed results. We find that WTP varies in systematic and expected ways with respect to factors such as the size of the water quality changes, average household income, and use/nonuse characteristics of respondents. As a whole, we conclude that our meta-regression results provide a reasonable basis for estimating expected WTP values for defined changes in water quality. However, despite a large number of existing economic valuation studies, relatively few could be meaningfully combined through meta-analysis due to heterogeneity in the commodities being valued in the original studies. Based on these findings, we provide recommendations for future research, including suggestions regarding more standardized approaches for defining water quality and reporting information in valuation studies.     

循环经济与低碳经济的关系分析——基于资源生产率

循环经济和低碳经济都是实现可持续发展的生产方式和生活模式,发展循环经济和低碳经济的根本共同点在于均需要提高广义资源生产率(生态效率),不同点在于实现可持续发展的途径和突破点等不同。本文基于资源产出率的理论分析、情景分析和实证研究,探讨了通过发展循环经济促进碳减排的途径。本文认为,通过提高资源生产率来提高碳生产率是可行的,其效果是资源效率效应和资源结构效应的叠加,可以此表征循环经济和低碳经济的相互关系。最后,我国1990—2005年的数据进行了实证分析。     

The service economy revisited

This article, after a critical appraisal of the main definitions of services in economics, proposes a concept of services based on process analysis. The new concept is used for a constructive purpose, to support a negative argument and to point out some directions of research. The constructive application extends the scope of the Leontief–Von Neumann–Sraffa type models. The negative application denies the existence of a correlation between the expansion of the service activities and an increasing dematerialization of the economy associated with knowledge and information. The final section suggests directions for future research on service outsourcing and unbalanced growth.     

Macroeconomic effects of fiscal policy changes: A case of South Africa

This study develops comprehensive full-sector macro-econometric models for the South African economy with the aim of explaining and providing the macroeconomic effects of fiscal policy changes in the country. The models are applied to test the effectiveness of fiscal policy actions in an economic environment with existing structural supply constraints versus demand-side constraints and also to detect which components of the fiscal would be more effective in stabilising the economy. Based on the structure of the South African economy and the framework presented, the study concludes that the South African economy can be characterised as one which is embedded with structural supply constraints. Thus, a model which is suitable for policy analyses of the South African economy needs to capture the long-run supply-side characteristics of the economy. A price block is incorporated to specify the price adjustment between the supply-side sector and real aggregate demand sector. The models are estimated with time-series data from 1970 to 2011, capturing both the long-run and short-run dynamic properties of the economy. The results from the series of fiscal policy scenarios suggest that fiscal policy actions are more effective in an economic environment with limited or no supply constraints. Fiscal expansion or consolidation that comes more from government spending changes will be more effective in an economic environment where structural supply constraints are absent while tax revenue changes will be more effective in an economic environment where there exist major structural supply constraints.     

State Strategies and the Geopolitics of the Global Knowledge Economy: China,India and the Case of Regenerative Medicine

The global competition between states for position in the uncertain future of the life sciences brings a new dynamic to the intersection between geopolitics and the global knowledge economy. Armed with distinctive approaches to innovation in new health technologies, the emerging economies of China and India are determined to challenge the traditional hegemony of the developed countries in areas such as regenerative medicine where the promised biotechnology future is said to lie. Yet although the political belief that there is a future value for regenerative medicine is global, the precise nature of that future when measured in terms of the path of the science, the market demand, the cultural response, the commercialisation process and its associated business models is obscure. Drawing on theories of the competition and developmental state, I analyse the factors that shape a state's response to the promise of regenerative medicine, the strategies of ‘speculative innovation’ that may be adopted in pursuit of geopolitical advantage in this uncertain field, and the adaptive qualities necessary for a state's effective competition in an age of globalisation. This analysis is then applied to the emerging economies of China and India to assess their geopolitical strategies in regenerative medicine innovation, their current position in this part of the knowledge bioeconomy, and their likely impact on its continuing globalisation.     

A framework for modelling economy-environment-development relationships based on dynamic carrying capacity and sustainable development feedback

A large literature exists that deals with economic issues of development and growth. It includes various approaches that can be classified as formal-theoretical, empirical-statistical and qualitative-verbal. Recently, the issue of sustainable development has been discussed much, which has given rise to some novel views on the relationship between development and environment. Most of these contributions utilize a more or less qualitative approach. A comprehensive inquiry of the relationship between economy, development, growth and environment may include an analytical approach as well. An analytical framework is proposed here for studies of environment-economy-development relationships that separates between economy, development, environment, and value system. A distinction is made between direct and indirect economy-environment interactions. To overcome disadvantages of assumptions of determinism in long term analysis a sustainable development feedback mechanism is proposed. It reflects anticipative behaviour to natural environmental changes in making long term decisions. This can be seen as a specific element of endogenous growth, namely one based on environmental factors. To illustrate the ideas a number of theoretical models are discussed that can be regarded as dynamic formal extensions of the concept of carrying capacity. Different cases include combinations of internal and external feedback mechanisms to an economy. The results demonstrate that in addition to behaviourial patterns that have been obtained by more complex studies other patterns may emerge.This study was supported by the Economic Research Foundation (Ecozoek), which resorts under the Netherlands Organization for Scientific Research (N.W.O.), project no. 450-230-007.This paper is based on reprocessed material from my Ph.D. dissertation. I am grateful to my thesis supervisors Peter Nijkamp and Hans Opschoor for comments at various stages in the research.     

Groundwater Management in a Food Security Context

This article analyzes the sustainability of market-based instruments such as tradable permits for the management of a renewable aquifer used for irrigated agriculture. In our dynamic hydro-economic model, a water agency aims at satisfying a food security constraint within a tradable permit scheme in the presence of myopic heterogeneous agents. We identify analytically the viability kernel that defines the states of the resource yielding inter-temporal feasible paths able to satisfy the set of constraints over time and the associated set of viable quota policies. We then illustrate the theoretical results of the paper with numerical simulations based on the Western La Mancha aquifer.     

The prospects for OPEC: A critical survey of models of the world oil market

The paper critically surveys seven recent models of the world oil market and their evaluations of the prospects for OPEC: Blitzer-Meeraus-Stoutjesdijk, Bohi-Russell, the U.S. Federal Energy Administration, Kennedy, Kalymon, Levy and Nordhaus. After a brief discussion of the basic approaches to the problem, we examine the model specifications in some detail. The principal contributions and conclusions are summarized, as are the main limitations of these models. We conclude with some suggestions of the most promising areas for future research.     

基于可持续景观设计的园林植物需水量评估——以美国加州庭院景观为例

随着中国经济社会的不断发展和城市化进程的快速推进,为了满足市民对美丽环境日益增长的需求,国家设计并建造了越来越多的城市公园和街头绿地。而面对我国普遍缺水的现状,科学有效地评价、设计、管理景观用水显得十分重要,但国内却鲜有对此关注。特别是园林植物养护用水,即园林植物需水量,直接关系着可持续景观建设的实现。美国加州很早开始了相关领域的研究,并将园林植物需水量评估方法强制应用于实际景观设计中,可快速量化计算设计场地未来的用水量,具有现实的借鉴和指导意义。分析了国内对于可持续景观用水的相关现状和问题,依据WUCOLS项目的研究与实践,详细介绍了美国加州现行应用于景观设计中的园林植物需水量量化评估方法,并基于某加州庭院景观设计项目展示园林植物需水量估算的实际应用,讨论美国加州园林植物需水量估算的优劣与意义,进而分析其借鉴的可能性和方法。以期在未来建立一个符合中国特色的园林植物用水量评估体系,从而推进今后的可持续景观设计与建设。     

中国生态经济学研究存在的问题及今后研究的建议

作者对中国生态经济学存在的问题进行了总结,并提出今后研究要点的建议。作者认为中国生态经济学多是对目标的描述,缺少方法和动力要素方面的深入研究。作者建议今后研究的要点放在消费偏好与的关系及约束高消耗生产体系的扩展方面。     

PERCEPTIONS, PROBLEMS AND METHODS OF PREPARING LABOUR FORCE ACCOUNTS IN INDIA

The paper concerns the links between labour force accounts and national accounts. It first discusses the variation in the perception of labour force among countries which results in much disparity in recorded participation rates. This obviously makes international comparison difficult. Since benchmark labour force information is often tied to population censuses which are infrequent and vary in concepts and approaches, even comparisons within a country over time are difficult. Finally a discussion of the use of labour force data to estimate the unrecorded economy is followed by suggestions on the direction for future work.     

Consumption externality, efficiency and optimal taxation in one-sector growth model

In an economy with consumption externalities, existing studies find that a competitive equilibrium is efficient in the long run and remains efficient in transitions if preferences are homothetic. This paper revisits the efficiency issue in an otherwise standard one-sector growth model where consumption externalities affect a utility via their effects on the time preference. We find that even if preferences are homothetic, the externality changes the marginal rate of substitution between now and future and leads to a disparity in the intertemporal elasticity of substitution between the centrally planned economy and a decentralized economy. As a result, a competitive equilibrium is inefficient in transition dynamics. We characterize an optimal tax/subsidy structure that enables the allocation in a decentralized economy to replicate the social optimum.