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Der fl?chendeckende Glasfaserausbau in Deutschland ist mit hohen Kosten verbunden. Insbesondere die Anschlüsse in dünn besiedelten Gebieten lassen die Kosten steigen. Die Autoren berechnen verschiedene M?glichkeiten der Kostenaufteilung.  相似文献   
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Challenges for land system science   总被引:3,自引:0,他引:3  
While considerable progress has been made in understanding land use change, land system science continues to face a number of grand challenges. This paper discusses these challenges with a focus on empirical land system studies, land system modelling and the analysis of future visions of land system change. Contemporary landscapes are contingent outcomes of past and present patterns, processes and decisions. Thus, empirical analysis of past and present land-use change has an important role in providing insights into the socio-economic and ecological processes that shape land use transitions. This is especially important with respect to gradual versus rapid land system dynamics and in understanding changes in land use intensity. Combining the strengths of empirical analysis with multi-scale modelling will lead to new insights into the processes driving land system change. New modelling methods that combine complex systems thinking at a local level with macro-level economic analysis of the land system would reconcile the multi-scale dynamics currently encapsulated in bottom-up and top-down modelling approaches. Developments in land use futures analysis could focus on integrating explorative scenarios that reflect possible outcomes with normative visions that identify desired outcomes. Such an approach would benefit from the broad and in-depth involvement of stakeholders in order to link scientific findings to political and societal decision-making culminating in a set of key choices and consequences. Land system models have an important role in supporting future land use policy, but model outputs require scientific interpretation rather than being presented as predictions. The future of land system science is strongly dependent on the research community's capacity to bring together the elements of research discussed in the paper, via empirical data collection and analysis of observed processes, computer simulation across scale levels and futures analysis of alternative, normative visions through stakeholder engagement.  相似文献   
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Since the outbreak of the financial and economic crisis, confidence in politicians as well as the economists in their advisory expert panels seems to be at an all-time low. Why do politicians reject science-based advice unless it fits into their political agenda? Are economists misunderstood by politicians and vice versa? The tension between the ideal of evidence-based policy-making and the reality of policy-based evidence-making is hardly a new phenomenon. Therefore, the expectation that Donald Trump, the Brexiteers and European populists will necessarily disappoint their voters because they simply cannot deliver what they have promised is misleading. Experts would be well advised to use the debate on the post-factual era as an impetus to reflect critically on their profession. One opinion expressed in this Zeitgespräch is that the contested societal and political impact of modern economics is due to its restricted scientific self-concept. A more open, pluralistic and transdisciplinary self-definition of economics would strengthen its societal influence. Another contributor ponders the proper incentives to persuade academic economists to provide economic policy advice. Key is the independence of advisory institutions like the German Council of Economic Experts. The selection of people with the best scientific qualifications will ensure the reputation of such institutions.  相似文献   
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This paper describes an econometric assessment of wine market prices for 21 of the Crus Classés châteaux in the Bordeaux region of France. The model developed in the analysis attempts to define the relationship between factors that influence wine quality and those that influence wine prices. Characteristics of the models are: (1) climate influences on grape composition (acid and sugar levels), (2) grape composition influences on market prices, (3) subjective quality evaluations (Parker‐points) on market prices, and (4) the effects of age of the wine on market prices. The results indicate that composition levels of Merlot‐dominated wines are more climate sensitive than those from Cabernet Sauvignon‐dominated wines. Overall, warm, dry summers result in high sugar and low acid levels at harvest which in turn lead to higher quality wines. Wine market price sensitivity to Parker‐point ratings indicates that properties with high Cabernet Sauvignon‐dominated wines are highly dependent on the external ratings while Merlot‐dominated wines have a decreased rating sensitivity. Smaller properties tend to gain over proportionally from high ratings indicating great jumps in price from year to year. Additionally, châteaux that have experienced high ratings for past vintages exhibit great sensitivity to point steps in ratings for current vintages. Aging has a positive effect on Bordeaux wine pricing. This is due to the increasing maturity as well as the increasing absolute scarcity. Absolute scarcity of product is expressed by the size of the property, with small properties producing less per vintage and therefore having less in the market. Additionally, Merlot‐dominated wines exhibit more maturing potential and profit more from aging than Cabernet Sauvignon‐dominated wines. Average per château real annual profit ranges from 1 to 10%. High levels of grape ripeness, absolute scarcity, and smaller properties that are dominated by Merlot in their blend lead to the highest profits. Forecasts for a vintage not yet on the market indicates that 1995 is better than 1994 for both Cabernet Sauvignon and Merlot‐dominated wines, but that 1996 and 1997 are not as good as 1995, especially for Merlot‐dominated wines.  相似文献   
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This article discusses the voucher--also called defined contribution--health care benefits model in terms of its features, the impetus for its development, obstacles to its implementation and the challenges it creates for employers. Although employers appear to have little current interest in health benefit vouchers, the author argues that a serious economic downturn could renew employers' interest in this promising concept.  相似文献   
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In many countries worldwide access networks are in the transition from copper to fiber access. During the transition phase copper and fiber networks are operated in parallel. All regulators facing this situation of technological change have to decide how to price unbundled access to the copper loop in this transition phase. Should they keep the usual forward looking long-run incremental cost standard charge, or should they move to some different approach? The authors propose to price copper access based on the modern equivalent asset (MEA) of fiber access. Since fiber access is superior to copper access, the cost of fiber access (as a basis for pricing copper access) should, however, be corrected by the performance delta between copper and fiber access.  相似文献   
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Humanity's role in shaping patterns and processes in the terrestrial biosphere is large and growing. Most of the earth's fertile land is used more or less intensively by humans for resource extraction, production, transport, consumption and waste deposition or as living space. Biomass production on cropland, grazing areas and in managed forests dominates area requirements, but other processes such as soil degradation, human-induced fires and expansion of settlements and infrastructure play an increasingly important role as well. The growing human domination of terrestrial ecosystems contributes to biodiversity loss as well as to a reduced capability of ecosystems to deliver vital services such as buffering capacity, soil conservation or self-regulation. This special section is devoted to the presentation of recent research into the patterns, determinants and implications of the human appropriation of net primary production (HANPP), an integrated socio-ecological indicator of land use intensity. By measuring the combined effect of land conversion and biomass harvest on the availability of trophic energy (biomass) in ecosystems, HANPP explicitly links natural with socioeconomic processes and allows for integrated analyses of land systems. This introductory article explains the rationale that links current HANPP research to Ecological Economics and discusses issues of definition and methods shared by all articles included in the special section. Finally, it gives an overview of the individual papers, provides some general conclusions and presents an outlook for future research: a better understanding of long-term trajectories of HANPP, of the significance of trade patterns as well as of the future role of bioenergy are highlighted as important issues to be addressed in the coming years.  相似文献   
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