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This article proposes a novel methodology to evaluate the visual impact of high-voltage lines in urban areas based on photographic images. The use of photographs allows for calculating the overall aesthetic impact while eliminating the subjective factors of the observer. To apply the proposed methodology based on photographs, the impact of the position and angle where the photograph was taken was analyzed, and a sensibility analysis was carried out. Moreover, it was applied to an application case, and a comparison with results from a previous study of a visual impact was performed. The methodology shows good performance and a better resolution of the indicator.

A presence on the web tends to be important for firms. Empirical studies show that firms with a better performance across various dimensions, and firms that are more internationally active, tend to have a website. Furthermore, a website helped firms to survive during the COVID-19 pandemic. An open question that is not discussed in the literature is how the use of online channels for sales is related to various dimensions of firm performance. This study contributes to the literature by using a unique recently released set of firm level data from Germany to investigate for the first time the links between online channels sales and firm characteristics. In a robustness check, the empirical investigation was replicated using strictly comparable firm level data from nine European countries, namely Austria, Belgium, Denmark, Finland, France, Ireland, Luxembourg, the Netherlands, and Sweden.

This paper uses firm-level data from the Flash Eurobarometer 421 survey conducted in June 2015 in 34 European countries to investigate the link between having a website and international firm activities in small- and medium-sized enterprises (SMEs). We find that firms that are present on the web more often export, import, engage in research and development cooperation with international partners, work as subcontractors for firms from other countries, use firms in other countries as subcontractors, and perform foreign direct investments—both inside and outside the European Union. The estimated website premia are statistically highly significant after controlling for firm size, country, and sector of economic activity. Furthermore, the size of these premia can be considered to be large. Internationally active firms tend to have a website.

This paper uses firm level data from World Bank Enterprise surveys conducted in 2019, and COVID-19 follow-up surveys conducted in 2020, in ten European countries to investigate the link between the gender of the firm’s owner and the firm’s survival until 2020. The empirical investigation uses econometric models that control for the firm’s characteristics that are known to be related to firm survival. The estimated effect of female ownership is positive ceteris paribus. Furthermore, the size of this estimated effect can be considered to be large on average. Having a female owner helped firms to survive.

This study attempts to replicate estimation results from Gábor Békés and Balázs Muraközy, Measuring productivity premia with many modes of internationalization, published in Economics Letters (2016). In this paper the authors use comparable firm-level data for seven European countriesbased on the EFIGE dataset to estimate the productivity premia of firms with various modes of internationalization by several empirical methods to demonstrate how results differ due to the method applied. While the EFIGE data are available free of charge from the web one core variable used by Békés and Muraközy is not, because total factor productivity (tfp) as computed by the authors is based on data from a commercial data base and, therefore, is available for users with a license to this database only. The freely available EFIGE data, however, come with another tfp-variable that can be used instead. In this replication study I use the EFIGE data with this publicly available tfp-variable to replicate (parts of) the estimations of Békés and Muraközy (2016) to see whether their results hold with the widely used public use version of the EFIGE data, too. It turns out that the big picture that emerges from using both productivity measures tends to be very similar. The use of the public use version of the EFIGE data for empirical investigations that deal with productivity, therefore, seems to be feasible.

This study replicates estimation results from Jennifer Abel-Koch, Who Uses Intermediaries in International trade? Evidence from Firm-level Survey Data, published in The World Economy (2013). In this paper she uses firm-level data from Turkey. The pure replication performed here that is based on a sample that differs only marginally from the sample used in the original study is successful. In addition to the pure replication I use firm-level data for Egypt from a highly similar survey. The most important result found by Abel-Koch for Turkey – a negative relationship between firm size and the intensity of use of intermediaries in exports – is found for Egypt, too. Results for the link between other firm characteristics and indirect exports via intermediaries, however, often turn out to be different.

This empirical paper documents the relationship between the composition of a firm’s workforce (with a special focus on age and gender) and its performance (productivity and profitability) for a large representative sample of enterprises from manufacturing industries in Germany using newly available, unique data. We find concave age-productivity profiles and a negative correlation of age on firms’ profitability. Moreover, our micro-econometric analysis reveals for the first time that the ceteris paribus lower level of productivity in firms with a higher share of female employees does not go hand in hand with a lower level of profitability in these firms.

In den Wirtschaftswissenschaften werden empirische Untersuchungen zur Überprüfung und Weiterentwicklung von theoretischen Modellen immer wichtiger. Dies schlägt sich auch in einer steigenden Anzahl von empirischen Beiträgen in Fachzeitschriften nieder, bei denen Wirtschaftsforschende eigene Forschungsdaten erhoben oder externe Datensätze verarbeitet haben. Allerdings gibt es bislang kaum effektive Möglichkeiten, diese Forschungsergebnisse im Kontext der zugehörigen Zeitschriftenartikel zu replizieren, zu prüfen oder für eine Nachnutzung und zur Unterstützung des wissenschaftlichen Diskurses bereit zu stellen. Der vorliegende Artikel analysiert die Gründe dafür, weshalb wirtschaftswissenschafliche Forschung häufig nicht replizierbar ist und formuliert Vorschläge dafür, wie diesen Herausforderungen begegnet werden kann. Empirical studies to verify and refine theoretical models are increasingly important in economics. This is also reflected in a rising number of empirical contributions to journals where authors have collected their own research data or used external datasets. However, so far there have been few effective means to replicate the published results within the framework of the corresponding article, to verify it, to make it available for repurposing or to use it to support scholarly debate. Our article reflects some of the principal reasons why economic research often is not replicable and suggests recommendations on how to meet these challenges.

In this note, we apply a new test by Lind and Mehlum (2010), casting doubt on the claim proposed by Blanchflower (2007) that the probability of unionisation follows an inverted U-shaped pattern in age with a maximum in the mid- to late 40s. With this new test for an inverted U-shaped pattern, which has not been applied to the age-membership nexus before, and by constructing exact confidence intervals for the maximum value, we demonstrate that – at least with respect to West Germany – Blanchflower’s hypothesis does not hold. Our findings suggest that more definitive evidence is needed before the existence of international unionisation-age patterns can be taken for granted.

A large and growing number of micro-econometric studies show that exporting firms are more productive than firms that sell their products on the home market only. This so-called exporter productivity premium qualifies as a stylized fact. Only recently researchers started to look at the role of extreme observations, or outliers, in shaping these findings. These studies use micro-econometric methods that are robust against outliers to show that very small shares of firms with extreme values drive the result. The large exporter productivity premium found for samples of firms including outliers are dramatically smaller in samples without these extreme observations. Evidence on this, however, is limited so far to firms from manufacturing industries. This note adds comparable evidence for firms from the business services industries. We find that the estimated exporter productivity premium is statistically significant and relevant from an economic point of view when a standard fixed effects estimator is used to control for unobserved firm characteristics, but that it drops to zero when a robust estimator is applied.F14

External-cavity quantum cascade lasers (EC-QCL) are now established as versatile wavelength-tunable light sources for analytical spectroscopy in the mid-infrared (MIR) spectral range. We report on the realization of rapid broadband spectral tuning with kHz scan rates by combining a QCL chip with a broad gain spectrum and a resonantly driven micro-opto-electro-mechanical (MOEMS) scanner with an integrated diffraction grating in Littrow configuration. The capability for real-time spectroscopic sensing based on MOEMS EC-QCLs is demonstrated by transmission measurements performed on polystyrene reference absorber sheets, as well as on hazardous substances, such as explosives. Furthermore, different applications for the EC-QCL technology in spectroscopic sensing are presented. These include the fields of process analysis with on- or even inline capability and imaging backscattering spectroscopy for contactless identification of solid and liquid contaminations on surfaces. Recent progress in trace detection of explosives and related precursors in relevant environments as well as advances in food quality monitoring by discriminating fresh and mold contaminated peanuts based on their MIR backscattering spectrum is shown.

Performance modeling of the characteristics of mid-infrared quantum cascade lasers (MIR QCL) is an essential element in formulating consistent component requirements and specifications, in preparing guidelines for the design and manufacture of the QCL structures, and in assessing different modes of operation of the laser device. We use principles of system physics to analyze the electro-optical characteristics of high power MIR QCL, including thermal backfilling of the lower laser level, hot electron effects, and Stark detuning during lasing. The analysis is based on analytical modeling to give simple mathematical expressions which are easily incorporated in system-level simulations of defense applications such as directed infrared countermeasures (DIRCM). The paper delineates the system physics of the electro-optical energy conversion in QCL and the related modeling. The application of the performance model to a DIRCM QCL is explained by an example.