Tests of Normality of Functional Data

The paper is concerned with testing normality in samples of curves and error curves estimated from functional regression models. We propose a general paradigm based on the application of multivariate normality tests to vectors of functional principal components scores. We examine finite sample performance of a number of such tests and select the best performing tests. We apply them to several extensively used functional data sets and determine which can be treated as normal, possibly after a suitable transformation. We also offer practical guidance on software implementations of all tests we study and develop large sample justification for tests based on sample skewness and kurtosis of functional principal component scores.     

Electrification of a city bus network—An optimization model for cost-effective placing of charging infrastructure and battery sizing of fast-charging electric bus systems

The deployment of battery-powered electric bus systems within the public transportation sector plays an important role in increasing energy efficiency and abating emissions. Rising attention is given to bus systems using fast charging technology. This concept requires a comprehensive infrastructure to equip bus routes with charging stations. The combination of charging infrastructure and bus batteries needs a reliable energy supply to maintain a stable bus operation even under demanding conditions. An efficient layout of the charging infrastructure and an appropriate dimensioning of battery capacity are crucial to minimize the total cost of ownership and to enable an energetically feasible bus operation. In this work, the central issue of jointly optimizing the charging infrastructure and battery capacity is described by a capacitated set covering problem. A mixed-integer linear optimization model is developed to determine the minimum number and location of required charging stations for a bus network as well as the adequate battery capacity for each bus line. The bus energy consumption for each route segment is determined based on individual route, bus type, traffic, and other information. Different scenarios are examined in order to assess the influence of charging power, climate, and changing operating conditions. The findings reveal significant differences in terms of required infrastructure. Moreover, the results highlight a trade-off between battery capacity and charging infrastructure under different operational and infrastructure conditions. This paper addresses upcoming challenges for transport authorities during the electrification process of the bus fleets and sharpens the focus on infrastructural issues related to the fast charging concept.     

Plant-level nonconvex output adjustment and aggregate fluctuations

In most manufacturing industries plant-level output is adjusted along three margins of capacity utilization: shiftwork, weekend work, and closing temporarily down. Due to the discrete and lumpy nature of these margins, only a fraction of plants adjust output in response to shocks. In a business cycle model calibrated to establishment-level observations, these nonconvexities make aggregate output less volatile than when plants can adjust smoothly. Further, the mass of adjusting plants is larger in downturns than in upturns, leading to counter-cyclical volatility of aggregate output and government policy being slightly more effective in recessions than in expansions.     

Heterogeneity in bank pricing policies: The Czech evidence

We estimate the pass-through from market interest rates to bank interest rates using heterogeneous panel cointegration techniques to address heterogeneity at the bank level in the Czech Republic. The results indicate heterogeneity in bank pricing in the short, but not in the long term. Mortgage rates and firm rates typically adjust to money market changes, but often less than fully in the long run. Large corporate loans have a smaller mark-up than small loans. Consumer rates have a high mark-up and do not exhibit a cointegration relationship with money market rates even in the long run. Next, we examine how bank characteristics determine the nature of interest rate pass-through in a cross-section of Czech banks. We find evidence for relationship lending, as banks with a stable pool of deposits smooth interest rates and require a higher spread as compensation. Large banks are not found to price their products less competitively. Greater credit risk increases vulnerability to money market shocks.     

Market selection with learning and catching up with the Joneses

We study the market selection hypothesis in complete financial markets, populated by heterogeneous agents. We allow for a rich structure of heterogeneity: individuals may differ in their beliefs concerning the economy, information and learning mechanism, risk aversion, impatience and ‘catching up with the Joneses’ preferences. We develop new techniques for studying the long-run behavior of such economies, based on Strassen’s functional law of the iterated logarithm. In particular, we explicitly determine an agent’s survival index and show how the latter depends on the agent’s characteristics. We use these results to study the long-run behavior of the equilibrium interest rate and the market price of risk.     

Research & development and growth: A Bayesian model averaging analysis

We examine the effect of research and development (R&D) on long-term economic growth using the Bayesian model averaging (BMA) to deal rigorously with model uncertainty. Previous empirical studies, which applied BMA, investigated the effect of dozens of regressors on long-term growth, but they did not examine the effect of R&D due to data unavailability. We extend these studies by proposing to capture the investment in R&D by the number of Nobel prizes in science. Using our indicator, the estimates show that R&D exerts a positive effect on long-term growth. This result is robust to many different parameter and model prior structures as well as to alternative definitions of R&D indicator.     

Individual and place-based drivers of self-employment in Chile

This paper analyzes the importance of individual and place characteristics on the selection into self-employment in Chile. Following a structural and multilevel empirical approach, we test whether both sets of variables explain the variation of individual wages, self-employed earnings, and the propensity of being in independent work. The results indicate that while most of the variation in these three outcomes is explained by individuals’ traits, place-related variables account for a non-negligible share of spatial variation. Second, as suggested by occupational choice theories, the propensity of being in self-employment positively correlates with larger expected earning differentials, but only in the case of employers. This, along with other results, suggests that while employers seem to choose their occupational status, own accounts in Chile seem to respond to factors pushing them into self-employment.     

Öffentliches und Geheimes

In the second half of 2009, the entire media agenda in Germany was dominated by the swine flu, next to the German Federal Parliament elections. Criticism was voiced in the media against the pharmaceutical industry for lobbying the nationwide swine flu vaccination, which was widely considered nothing but a product of the industry’s lobbying power. In order to avoid the usual interviews with lobbyists, we attempted to apply a new methodological framework approach in analysing lobbying processes and key stakeholders in the public sphere—and outside. Crucial to the diversified approach, which involves quantitative content analysis of media coverage and press releases, are interviews with journalists, lobbyists’ network analysis and internet research on biographies. Although a conspiracy could not be conclusively proven, the results do indicate associations that validate the criticism of the industry’s lobbying activities.     

Enterprise Mashup Systems as Platform for Situational Applications

Currently, several Enterprise 2.0 platforms are beginning to emerge. This paper introduces Enterprise Mashup technology as a means to improve IT alignment of individual work processes and changing business needs. Enterprise Mashups enable users to create customized applications to easily find and transform business information and functionalities, as well as collaboratively share pre-built Mashup applications. Therefore, the concept of Enterprise Mashups integrates Web 2.0 technologies and principles with well-established paradigms such as Enterprise Information Integration, Business Intelligence, and Business Process Management. Involved organizational key drivers, technical challenges and inhibitors are discussed to assess the potential business value and explain the emerging expansion of Mashup platforms in companies.