Techno-ökonomische Bewertung von Energie-Autarkie für die Energieversorgung von Einfamilienhäusern

Many consumers currently follow the idea of energy self-sufficiency and try to contribute to meet their energy needs in order to become independent and self-sufficient from the central power supply system. In order to achieve load-oriented energy self-sufficiency the provision of energy must cover the full energy demand at any time. Against this background, in this paper the costs and potentials of a load-oriented energy self-sufficiency of single-family homes are analysed. Thereby it is differentiated between electricity-, heat- and energy self-sufficiency. The modelling is carried out with the simulation environment ?Polysun Designer“ which allows a high temporal dynamic simulation of the annual energy demand and supply.The results show that, within the investigated supply variations, the highest levels of energy self-sufficiency can be achieved by an energy supply system completely based on electricity using a combination of PV; heat pump and battery storage. Depending on the building standard, a maximum of 45 (existing buildings) and 71?% (new buildings) of the building’s energy demand can be covered with renewable energy. The economic evaluation however has shown that under present conditions, none of the investigated supply variants can compete with conventional energy supply (public grid connection + gas condensing boiler).     

Obfuscation and Rational Inattention*

We study the behavior of duopolistic firms that can obfuscate their prices before competing on price. Obfuscation affects the rational inattentive consumers' optimal information strategy, which determines the probabilistic demand. Our model advances related models by allowing consumers to update their unrestricted prior beliefs with an informative signal of any form. We show that the game may result in an obfuscation equilibrium with high prices or a transparency equilibrium with low prices and no obfuscation, providing an argument for market regulation. Obfuscation equilibria cease to exist for low information costs and if one firm seems a priori considerably more attractive.     

State of the German Short-Term Power Market

The paper at hand provides a comprehensive overview of the current state of the German short-term power market with focus on trading and efficiency. The pivotal question is whether current market designs are appropriate to maximise social welfare. If this can’t be confirmed, trade-offs between technical restrictions, transparency requirements, the structure of the supply side and regulators focusing mainly on consumer surplus are analysed, which prevent markets from being fully efficient. The emphasis is on Germany due to it’s central location in Europe, it’s sheer size and the rapid increase of renewable generation in recent years. This development forced the German power market into a state of transition. As a result, developments in Germany might serve as a blueprint for other European countries. The introduction of negative day-ahead prices, the implementation of a very liquid intraday trading, a quarter hourly auction and market-based systems for the procurement of Ancillary Services are just some examples of Germany’s pioneering role. On the other hand, negative effects of the rapid changes such as the excessive use of non-market based redispatch measures and system endangering imbalance price regimes shall also be explored. As a matter of course, cross-references to other European countries and harmonisation projects are included as the German market is well interconnected with neighbouring markets.     

Pairs trading with a mean-reverting jump–diffusion model on high-frequency data

This paper develops a pairs trading framework based on a mean-reverting jump–diffusion model and applies it to minute-by-minute data of the S&P 500 oil companies from 1998 to 2015. The established statistical arbitrage strategy enables us to perform intraday and overnight trading. Essentially, we conduct a three-step calibration procedure to the spreads of all pair combinations in a formation period. Top pairs are selected based on their spreads’ mean-reversion speed and jump behaviour. Afterwards, we trade the top pairs in an out-of-sample trading period with individualized entry and exit thresholds. In the back-testing study, the strategy produces statistically and economically significant returns of 60.61% p.a. and an annualized Sharpe ratio of 5.30, after transaction costs. We benchmark our pairs trading strategy against variants based on traditional distance and time-series approaches and find its performance to be superior relating to risk–return characteristics. The mean-reversion speed is a main driver of successful and fast termination of the pairs trading strategy.     

Science and proven experience: a Swedish variety of evidence-based medicine and a way to better risk analysis?

A key question for evidence-based medicine (EBM) is how best to model the way in which EBM should ‘[integrate] individual clinical expertise and the best external evidence’. We argue that the formulations and models available in the literature today are modest variations on a common theme and face very similar problems when it comes to risk analysis, which is here understood as a decision procedure comprising a factual assessment of risk, the risk assessment, and the decision what to do based on this assessment, the risk management. Both the early and updated models of evidence-based clinical decisions presented in the writings of Haynes, Devereaux and Guyatt assume that EBM consists of, among other things, evidence from clinical research together with information about patients’ values and clinical expertise. On this A-view, EBM describes all that goes on in a specific justifiable medical decision. There is, however, an alternative interpretation of EBM, the B-view, in which EBM describes just one component of the decision situation (a component usually based on evidence from clinical research) and in which, together with other types of evidence, EBM leads to a justifiable clincial decision but does not describe the decision itself. This B-view is inspired by a 100-years older version of EBM, a Swedish standard requiring medical decision-making, professional risk-taking and practice to be in accordance with ‘science and proven experience’ (VBE). In the paper, we outline how the Swedish concept leads to an improved understanding of the way in which scientific evidence and clinical experience can and cannot be integrated in light of EBM. How scientific evidence and clinical experience is integrated influences both the way we do risk assessment and risk management. In addition, the paper sketches the as yet unexplored historical background to VBE and EBM.     

How Relevant Is Government Championing Behavior in Technology Development?

Many studies emphasize the importance of government support in technology development. However, this study is among the first to provide empirical findings of the relevance of government roles for the performance of technology development projects. Based on earlier research and the strategic management literature, a theoretical model and hypotheses are developed to study the relevance of government roles and project teams' strategic behavior for technology development projects. Our results show that government championship is an important positive factor for the performance of technology development projects. Government championing behavior overcomes regulatory barriers, enthusiastically promotes the technology's advantages, and gets key decision makers involved. As such, government championship has more impact than government financial/technical assistance on both project performance and benefits to customers. The findings also show that both the proactiveness and defensiveness dimensions of project teams' strategic behavior contribute positively to project performance and benefits to customers. The paper concludes with implications for practice: From a policy perspective, government should extend its technology policies by taking on the role as a champion, while companies should invest in building professional relations with champions in government.     

Interplay of computer and paper-based sketching in graphic design

The purpose of this study is to investigate student designers’ attitude and choices towards the use of computers and paper sketches when involved in a graphic design process. 65 computer graphic technology undergraduates participated in this research. A mixed method study with survey and in-depth interviews was applied to answer the research questions. This result shows that sketches and computers as design tools help students generate ideas in the early stage of design. Students’ preferences to use sketches or computers differ, since each tool has its own advantages and disadvantages.     

Limits of semistatic trading strategies

We show that pointwise limits of semistatic trading strategies in discrete time are again semistatic strategies. The analysis is carried out in full generality for a two-period model, and under a probabilistic condition for multiperiod, multistock models. Our result contrasts with a counterexample of Acciaio, Larsson, and Schachermayer, and shows that their observation is due to a failure of integrability rather than instability of the semistatic form. Mathematically, our results relate to the decomposability of functions as studied in the context of Schrödinger bridges.     

Do traders learn to select efficient market institutions?

Experimental Economics - When alternative market institutions are available, traders have to decide both where and how much to trade. We conducted an experiment where traders decided first whether...