Electricity, carbon and weather in France: where do we stand ?

As a tool to fight long run changes in climate the European Union explicitly introduced the emission trading scheme (EU ETS) on January 1, 2005, which aimed at reducing carbon emission by 8% by 2012, and was designed to operate in two phases. Using data related to the first phase, this article investigates the role that the EU ETS plays in the power generation market by taking into account the existence of possible cross-spillovers between the French carbon and the French electricity spot markets, the spot prices of natural gas and of oil, and climatic conditions in France and elsewhere. Results show that there is no short run relationship between the electricity and carbon returns, while there is a long run relationship. However, this relationship suffers from a disequilibrium in that the electricity price readjust in the long run. We also find that while there are own mean and own volatility spillovers in the two markets, there are no cross own mean and own volatility spillovers, indicating that the electricity spot market and the carbon spot market are not integrated. Finally, results underline the limited impact of weather on the interconnection of these markets.Carbon market, Electricity, Weather, Multivariate GARCH

Gauging as constraining: the universal generalised geometry action in two dimensions

One of the central concepts in modern theoretical physics, gauge symmetry, is typically realised by lifting a finite-dimensional global symmetry group of a given functional to an infinite-dimensional local one by extending the functional to include gauge fields. In this contribution we review the construction of gauged actions for two-dimensional sigma models, considering a more general notion to be gauged, namely that of a (possibly singular) foliation. In particular, the original action does not need to have any global symmetry for this purpose. Moreover, reformulating the ungauged theory by means of auxiliary 1-form fields taking values in the generalised tangent bundle over the target, all possible such gauge theories result from restriction of these fields to take values in (possibly small) Dirac structures. This turns all the remaining 1-form fields into gauge fields and leads to the presence of a local symmetry. We recall all needed mathematical notions, those of (higher) Lie algebroids, Courant algebroids, and Dirac structures.Comment: 20 pages; proceedings of "Recent Developments in Strings and Gravity", Corfu Summer Institute 201

Beyond the standard gauging: gauge symmetries of Dirac Sigma Models

In this paper we study the general conditions that have to be met for a gauged extension of a two-dimensional bosonic sigma-model to exist. In an inversion of the usual approach of identifying a global symmetry and then promoting it to a local one, we focus directly on the gauge symmetries of the theory. This allows for action functionals which are gauge invariant for rather general background fields in the sense that their invariance conditions are milder than the usual case. In particular, the vector fields that control the gauging need not be Killing. The relaxation of isometry for the background fields is controlled by two connections on a Lie algebroid L in which the gauge fields take values, in a generalization of the common Lie-algebraic picture. Here we show that these connections can always be determined when L is a Dirac structure in the H-twisted Courant algebroid. This also leads us to a derivation of the general form for the gauge symmetries of a wide class of two-dimensional topological field theories called Dirac sigma-models, which interpolate between the G/G Wess-Zumino-Witten model and the (Wess-Zumino-term twisted) Poisson sigma model.Comment: 1+27 pages; version 2: minor correction in the introduction; version 3: minor corrections to match published version, references updated, acknowledgement adde

Electricity, carbon and weather in France: where do we stand ?

As a tool to fight long run changes in climate the European Union explicitly introduced the emission trading scheme (EU ETS) on January 1, 2005, which aimed at reducing carbon emission by 8% by 2012, and was designed to operate in two phases. Using data related to the first phase, this article investigates the role that the EU ETS plays in the power generation market by taking into account the existence of possible cross-spillovers between the French carbon and the French electricity spot markets, the spot prices of natural gas and of oil, and climatic conditions in France and elsewhere. Results show that there is no short run relationship between the electricity and carbon returns, while there is a long run relationship. However, this relationship suffers from a disequilibrium in that the electricity price readjust in the long run. We also find that while there are own mean and own volatility spillovers in the two markets, there are no cross own mean and own volatility spillovers, indicating that the electricity spot market and the carbon spot market are not integrated. Finally, results underline the limited impact of weather on the interconnection of these markets

Do mountain tourists demand ecotourism? Examining moderating influences in an Alpine tourism context

Ecotourists appreciate nature and are willing to learn about nature and ecology. Therefore ecotourism is often seen as a product package that supports sustainable tourism development. This study contributes to existing research in the field of ecotourism as it investigates how travel motives and environmental concern of mountain tourists influences their actual demand for ecotourism. A survey of mountain tourists in the Austrian Alps was conducted and reveals a positive relationship between environmental concern and ecotourism demand. The study measured travel motives, which are compatible and incompatible with ecotourism and showed how these motives influence actual demand of ecotourism. Furthermore it is postulated that education, income and the intention to revisit the destination moderate the relationship between environmental concern, mountain tourists’ motives and the tourists’ demand for ecotourism. For destination marketing it can be stated that higher educated mountain tourists with a high disposable income are a vital market segment, which should be targeted for ecotourism in the mountains. Research recommendations are highlighted and focus on loyal visitors, as it remains unclear whether loyalty with an ecotourism destination strengthens the demand for ecotourism

The price impact of extreme weather in developing countries

We examine the impact of extreme weather on consumer prices in developing countries by constructing a monthly data set of potential hurricane and flood destruction indices and linking these with consumer price data for 15 Caribbean islands. Our econometric model shows that the price impact of extreme weather events can be large. To illustrate potential welfare losses due to these price effects, we combine our estimates with price elasticities obtained from a demand system and with event probabilities for Jamaica. Our results show that while expected monthly losses are small, rare events can cause large falls in monthly welfare due to price increases

From the Behavior Model of an Animated Visual Language to its Editing Environment Based on Graph Transformation

Animated visual models are a reasonable means for illustrating system behavior. However, implementing animated visual languages and their editing environments is difficult. Therefore, guidelines, specification methods, and tool support are necessary. A flexible approach for specifying model states and behavior is to use graphs and graph transformations. Thereby, a graph can also represent dynamic aspects of a model, like animations, and graph transformations are triggered over time to control the behavior, like starting, modifying, and stopping animations or adding and removing elements. These concepts had already been added to Dia-Meta, a framework for generating editing environments, but they provide only low-level support for specifying and implementing animated visual languages; specifying complex dynamic languages was still a challenging task. This paper proposes the Animation Modeling Language (AML), which allows to model behavior and animations on a higher level of abstraction. AML models are then translated into low-level specifications based on graph transformations. The approach is demonstrated using a traffic simulation

Entrepreneurial Leadership in Austrian Family SMEs:A Configurational Approach

This article explores the role of stewardship practices related to entrepreneurial leadership in turning entrepreneurial orientation (EO) into family firm performance while considering its environmental context. Family business research has not fully investigated how the EO–financial performance relationship depends on configurations of internal and external factors which establish strategic fit. We argue that family firms can overcome the often- highlighted paternalism-entrepreneurship paradox by employing stewardship practices related to entrepreneurial leadership (internal factor), which in turn can help them leverage strategic fit between EO and dynamic environments (external factor). The results of a survey of 162 Austrian small and medium-sized family enterprises (family SMEs) show that family SMEs can only profit from EO under certain configurations of internal and external factors. Employing stewardship practices related to entrepreneurial leadership turns out to be an efficient and necessary condition for transforming EO into performance. Environmental dynamism is, furthermore, a double-edged sword facilitating and impeding the transformation of EO into performance. These findings contribute to existing research by shedding light on the role of stewardship practices in establishing strategic fit in entrepreneurial family firms

Rekonstruktion und Fremdverstehen im qualitativen Interview

"Das qualitative Verfahren des 'narrativen Interviews' hat den Anspruch, durch die 'Hervorlockung' sogenannter Stegreiferzählungen zu Geschichten über soziale Realität zu gelangen, wie sie 'tatsächlich' erlebt wurden. Die Erfahrung zeigt dagegen, daß dies häufig nicht erfolgt: Gerade die Interaktionssituation dieser Technik nämlich, in der die Interviewenden bei der Erzählung der Interviewten zunächst überhaupt nicht intervenieren dürfen, kann dazu benutzt werden, der Erzählung fiktionale Anteile hinzuzufügen. Der Prozeß der Rekonstruktion subjektiv erlebter sozialer Realität sollte daher in einem dialogisch geführten, der alltäglichen Interaktion ähnlichen Interview erfolgen, in der es den Interviewenden z. B. auch erlaubt ist, vorsichtig das Erzählte in Zweifel zu ziehen. Ein auf diese Weise geführtes 'rekonstruktives Interview' versteht die qualitative Datenerhebung als einen Aushandlungsprozeß, in dem die Interviewten 'Experten' sind für das in ihrer Biographie Erlebte, die Interviewenden für die Technik des dialogischen Rekonstruktionsprozesses. Das Verstehen des fremden Sinns wird demzufolge nicht als ein Aufgehen im Fremden begriffen, sondern als eine Annäherung an das Fremde durch die Verschränkung der Perspektiven des Fragenden und des Befragten. Diese Annäherung kann nicht dadurch erreicht werden, daß ein Interaktionspartner seine Perspektive möglichst weit zurücknimmt und möglichst wenig sichtbar macht, sondern sie entsteht als 'gemeinsamer Boden' während des Dialogs. Diese Überlegungen rücken die Frage wieder stärker in das Zentrum des Forschungsgeschehens. Erst die Frage kann mich dem näherbringen, was sich hinter einem Begriff verbirgt, den der andere verwendet; sie kann das eigene Vorverständnis für das Fremde öffnen. Ein dialogischer Prozeß, der durch die Ordnungsleistung der Frage strukturiert wird, kann zwar den kategorialen Unterschied zwischen dem Eigenen und dem Fremden nicht aufheben, aber er kann konsensuelle Fixpunkte setzen, die eine Brücke zum Fremden tragen und eine kommunikative Annäherung an den subjektiven Sinn des anderen möglich machen." (Autorenreferat

The behaviour of random forest permutation-based variable importance measures under predictor correlation

<p>Abstract</p> <p>Background</p> <p>Random forests (RF) have been increasingly used in applications such as genome-wide association and microarray studies where predictor correlation is frequently observed. Recent works on permutation-based variable importance measures (VIMs) used in RF have come to apparently contradictory conclusions. We present an extended simulation study to synthesize results.</p> <p>Results</p> <p>In the case when both predictor correlation was present and predictors were associated with the outcome (H_A), the unconditional RF VIM attributed a higher share of importance to correlated predictors, while under the null hypothesis that no predictors are associated with the outcome (H₀) the unconditional RF VIM was unbiased. Conditional VIMs showed a decrease in VIM values for correlated predictors versus the unconditional VIMs under H_Aand was unbiased under H₀. Scaled VIMs were clearly biased under H_Aand H₀.</p> <p>Conclusions</p> <p>Unconditional unscaled VIMs are a computationally tractable choice for large datasets and are unbiased under the null hypothesis. Whether the observed increased VIMs for correlated predictors may be considered a "bias" - because they do not directly reflect the coefficients in the generating model - or if it is a beneficial attribute of these VIMs is dependent on the application. For example, in genetic association studies, where correlation between markers may help to localize the functionally relevant variant, the increased importance of correlated predictors may be an advantage. On the other hand, we show examples where this increased importance may result in spurious signals.</p