Contributions in Merlin

In this paper I derive a sucient condition for a numeri-cally computed -equilibrium of a dynamic stochastic economy with heterogeneous agents to be close to an exact equilibrium. If the economic fundamentals are semi-algebraic, one can verify computationally whether this condition holds. The condition can be interpreted economically as a robustness requirement on the set of -equilibria that form a neighborhood of the computed approximation. I use this method of 'self-validating computation' to prove that in realistically calibrated stochastic overlapping generation models, competitive equilibria can often be extremely well approximated by cubic functions, mapping the current shock and the beginning-of-period wealth-distribution to current endogenous variables.

Wie lässt sich die Unternehmenstätigkeit finanzieren? Wie viel Fremd- und wie viel Eigenkapital ist nötig? Welche Investitionsprojekte lohnen sich? Wie viel ist das Unternehmen wert? Welche Finanzmärkte und -instrumente gibt es? Wie werden die Ziele Liquidität, Sicherheit, Rendite und Wachstum optimal aufeinander abgestimmt? Auf diese und viele weitere Fragen zu Finanzierung und Investition gibt dieses Buch umfassend Antwort. Es bietet durch seine konzeptionelle, frameworkartige Darstellung einen Denk- und Argumentationsraster, mit dem sich finanzielle Fragen systematisch angehen lassen. Zahlreiche Texte aus der Wirtschaftspresse illustrieren die Umsetzung in die Praxis. Kontrollfragen und Antworten sowie Übungsaufgaben und aktuelle Fallstudien erlauben eine gezielte Vertiefung des Stoffes. Praktisch: Herausnehmbares Faltblatt mit allen Formeln, Abkürzungen und Symbolen.

Recently, a number of authors have argued that the standard search model cannot generate the observed business-cycle-frequency fluctuations in unemployment and job vacancies, given shocks of a plausible magnitude. We propose a new calibration strategy of the standard model that uses data on the cost of vacancy creation and cyclicality of wages to identify the two key parameters - the value of nonmarket activity and the bargaining weights. Our calibration implies that the model is consistent with the data.

Gedanken aus der Abschiedsvorlesung zum Thema «Geld und Geist – oder: Von Mäusen und Menschen», gehalten am 22. Mai 2008 an der Universität Zürich.

Führt Ressourcenknappheit, das Monatsthema dieser Ausgabe, zu Ressourcenkonflikten, wie oft behauptet wird? Länder mit Erdölvorkommen – global gesehen eine knappe Ressource – weisen tatsächlich ein erhöhtes Kriegsrisiko auf. Andererseits ist Wassernutzung nur selten mit Kriegen verbunden und führt mehrheitlich zu kooperativen Lösungen. Vertieft man sich in die Zusammenhänge zwischen Ressourcenknappheit und Konflikten, sieht man schnell, dass diese sehr komplex sind und dass Konflikte im Kontext knapper Ressourcen nicht die Regel sein müssen. Gewisse Muster lassen sich aber erkennen. Diese helfen, optimale Strategien zu identifizieren, um Ressourcenkonflikte zu vermeiden oder zu lösen. Dazu sollte auch die Schweiz einen Beitrag leisten, unter anderem, weil wir Ressourcen aus Konfliktgebieten konsumieren.

The trend towards a global orientation of the companies leads more frequently to a distributed software development. Due to an inappropriate communication requirements get often misunderstood, an inadequate software solution is developed as a consequence. Handshaking represents a structured communication process between stakeholders which uses a new technology called implementation proposal to associate design decisions with the specified requirements. It helps to develop a better understanding for the system to be designed. Thus potential problems can be caught at early stages of the system development. This thesis describes a concept, how Handshaking can be supported by a software solution using the ADORA modelling language. Further it introduces a composition algorithm which makes it possible to dynamically generate implementation proposals straight from the system model. An evaluation of the concept with a prototypical implementation in the form of an Eclipse plug-in yielded promising results and showed that the realization carries further potential.

This paper describes the implementation of finite-state based, high precision morphological tools for the generation and analysis of open word classes based on the inflection classes for German of the Open Lexicon Interchange Format (OLIF). Productive compounding and derivations are treated by simple word formation rules. The latter is constrained by selective frequency checks over the web and corpora. Minimal lexicographic requirements (only stem and a numeric inflectional code) allow simple expandability and define a morphological abstraction layer which existing finite state morphological systems do not exhibit. Although a lot of lexical information is freely available for end users over the web, the same is not true for resources which will be used in NLP applications. Therefore, we initiate an open and shared morphological OLIF-based resource where we integrate material from sources which allows for such a term of use.

Users of online tourism communities are confronted with the constant increase of information. A suitable solution for an efficient access to this growing amount of data could be personalizing methods which automatically present the content trimmed to the context of an individual user. Based on the research on the concept of personalization, the six most popular methods are presented and discussed. These methods require a significant amount of metadata to filter the requested information according to the user context. Several Web 2.0 concepts are presented, which can be used to generate this metadata. The acquired basic understanding of personalization concepts and methods is then applied on the area of existing online tourism communities. To discuss these circumstances, a selection of todayís online travel communities is empirically analyzed. The results of this paper show that the large amount of interest found in literature, research and science on the subject of personalization is not a reflection of the amount found in existing online tourism communities.

In big financial institutions, the application landscape for collecting and controlling trading data is usually quite complex and versatile. Interfaces for data reconciliation between different systems namely front, middle and back office, hold the risk of incon-sistencies, particularly if the data is represented and pre-processed in many different ways. The process of analysis, validation and correction of issues in the reconciliation process usually requires high manual effort. Therefore, the topic of this diploma thesis is the discovery of patterns or correlations in these reconciliation inconsistencies. This allows optimizing the systems and minimizing the manual effort in long term. It is shown by theory and practical examples how to discover novel & potentially useful patterns and hidden logic by applying classic propositional as well as multi-relational data mining approaches. We check whether they make sense in the given live environment of Credit Suisse and how they bring an added value in terms of summarizing data into useful information and knowledge. While considering, applying and evaluating them, the main focus is on achieving a better understanding of the data and the systems.