Wirkung eines Anstiegs der Öl- und Gaspreise auf die deutsche Wirtschaft

Die Entwicklung in den vergangenen Jahren hat gezeigt, dass die Öl- und Gaspreise beträchtlichen Schwankungen unterliegen. Dabei ist klar geworden, dass langfristig die Knappheit der Ressourcen die Preise der fossilen Energieträger dramatisch steigern wird. Die Ressourcen sind begrenzt, aber die Nachfrage insbesondere der boomenden Schwellenländer wie China und Indien treibt die Ressourcenpreise. Dieser Trend ist von erheblichen Schwankungen begleitet, weil die Wechselfälle der weltpolitischen Lageentwicklung Unsicherheiten auf den Märkten erzeugen, und außerdem je nach der konjunkturellen Entwicklung die Raffineriekapazitäten weltweit unterschiedlich ausgelastet sind. Somit ist eine Vorhersage der Ölpreisentwicklung in der mittleren Frist - also für die nächsten drei oder vier Jahre - außerordentlich schwierig. Gleichwohl halten Experten einen Anstieg des Ölpreises auf 100 US $ pro Barrel bis zum Jahr 2010 für denkbar. Welche Wirkung hätte dies für die deutsche Volkswirtschaft? Dieser Frage wollen wir nachgehen, wobei wir unterstellen, dass die Gaspreise denselben prozentualen Aufschlag erfahren, wie dies in der Vergangenheit ja auch immer der Fall gewesen ist

Reducing Resource Consumption. A Proposal for Global Environmental Policy.

The world has just recognized that market failures of the global financial system have the power to destroy the entire economy. Short term profit maximization and wrong prices of the products are the problematic factors. Even the CEO`s of leading financial institutions demand a framework of rules that is able to avoid for the future what just has happened. The same reasons are responsible for the destruction of nature as a result of the economic process and insofar there is a window of opportunity for a general structural change in global policy. But the analogy is not perfect because the environmental problem is a long run problem and the coming catastrophe is not seen by everyone. Further many of those who are convinced that we have to act now see several distinct problems that are identified as externalities of the economic process and do not accept that we have a systematic problem. The paper at hand addresses this conflict and asks for a pragmatic policy proposal that will be able to induce a more sustainable economic development

Beyond Icons: Towards New Metaphors for Visual Query Languages for Spatial Information Systems

We argue that those metaphors currently used for the design of user interfaces to databases and for visual query languages are not sufficient in the context of spatial information systems for they do not take advantage of the natural intuitive properties of spatial data. The paper proposes a new metaphor for handling spatial data, termed the blackboard metaphor, which overcomes these drawbacks. Based upon this paradigm a fully-fledged visual logic query language for spatial information systems called Sketch! is introduced. Its major advantage is that it facilitates a very intuitive, natural way to express spatial queries

Stylised Facts and the Contribution of Simulation to the Economic Analysis of Budgeting

The application of computer simulation as a research method raises two important questions: (1) Does simulation really offer added value over established methods? (2) How can the danger of arbitrariness caused by the extended modelling possibilities be minimised? We present the concept of stylised facts as a methodological basis for approaching these questions systematically. In particular, stylised facts provide a point of reference for a comparative analysis of models intended to explain an observable phenomenon. This is shown with reference to a recent discussion in the "economic analysis of accounting" literature where established methods, i.e. game theory, as well as computer simulations are used: the susceptibility of the "Groves mechanism" to collusion. Initially, we identify six stylised facts on the stability of collusion in empirical studies. These facts serve as a basis for the subsequent comparison of four theoretical models with reference to the above questions: (1) We find that the simulation models of Krapp and Deliano offer added value in comparison to the game theoretical models. They can be related to more stylised facts, achieve a better reproduction and exhibit far greater potential for incorporating yet unaddressed stylised facts. (2) Considered in the light of the stylised facts to which the models can be related, Deliano's simulation model exhibits considerable arbitrariness in model design and lacks information on its robustness. In contrast, Krapp demonstrates that this problem is not inherent to the method. His simulation model methodically extends its game theoretical predecessors, leaving little room for arbitrary model design or questionable parameter calibration. All in all, the stylisedfactsconcept proved to be very useful in dealing with the questions simulation researchers are confronted with. Moreover, a "research landscape" emerges from the derived stylised facts pinpointing issues yet to be addressed.Computer Simulation, Stylised Facts, Methodology, Groves Mechanism, Collusion, Game Theory

Quantum Dynamics in a Ferromagnetic Atomic Gas

Bose-Einstein condensates (BECs) provide an extraordinary system to study many-body quantum effects with a high degree of control. Using such ultra-cold gases, microscopic quantum effects become visible on a macroscopic scale as thermal fluctuations are negligible. In particular, quantum phase transitions can be observed. These phase transitions can be indicated by an order parameter that abruptly changes at the critical value of a certain control parameter. Throughout this work, a spin-1 BEC with ferromagnetic interactions and zero magnetization is considered. This system exhibits three ground-state quantum phases that can be controlled by an effective magnetic field. These phases have been explored both theoretically and experimentally in the last two decades. Quantum phase transitions are by definition only applicable to the ground state of a system. However, this powerful concept can be extended to states with non-zero energy. Such excited-state quantum phase transitions (ESQPTs) can be driven by a conventional control parameter, but, interestingly, also by a variation of the excitation energy only. ESQPTs have been studied theoretically and their existence itself has been revealed, e.g., in molecular spectra. However, a thorough investigation by an order parameter and in particular the experimental mapping of the corresponding phase diagram remain an open challenge in any physical system. In this thesis, an interferometric order parameter is employed to experimentally map out an excited-state quantum phase diagram. This order parameter is based on dynamical behavior of coherent states that resemble the mean-field phase-space trajectories of excited-state phases. While a ferromagnetic spin-1 BEC with zero magnetization serves as an exemplary platform, the findings can be applied to other quantum systems with similar Hamiltonians. Importantly, the distinction of excited-state quantum phases utilizes the excitation energy as a second control parameter, which presents a key feature of ESQPTs. Our experiments therefore extend the powerful concept of quantum phases and quantum phase transitions to the entire Hilbert space of the spin-1 BEC

National economic policy simulations with global interdependencies : a sensitivity analysis for Germany

"Policy simulations for national economies with econometric models in general are done using a stand alone national model with exogenous export values and import prices. In a globalised world such an exercise is critical, since the policy in question may change the export prices and the import volumes of the particular country and induce via international trade a change of the economic activities of the global economy and a feed back to the export values and import prices of the particular country. The paper at hand presents a sensitivity analysis for Germany comparing the impacts of a shock on investment in a stand alone simulation using the multisector model INFORGE with the results, which occur, if the same model is linked to the global multicountry/multisector model GINFORS endogenising Germany's export values and import prices. The results are striking: The effect on real GDP is 50% higher in the global simulation than in the stand alone case. Because of the specialisation in trade the differences on the sector level are even stronger." (Author's abstract, IAB-Doku) ((en))Wirtschaftspolitik, Globalisierung - Auswirkungen, Export, Preisniveau, Importquote, Exportquote, Welthandel, Ökonometrie - Modell, Bruttoinlandsprodukt, volkswirtschaftliche Gesamtrechnung, Außenhandelspolitik, Außenhandelsentwicklung