Spatial effects of open borders on the Czech labour market

"Hardly noticed in Western Europe the fall of the Iron Curtain had also effects on the regional structures of the labour markets in the Central and Eastern European Countries (CEEC). I analyse whether during the undoubtedly increasing integration of markets the Czech border region close to the Western European high-wage countries benefited from its geographical position. Even without transnational free labour mobility, free trade and outsourcing of production activities can lead to shifts in the labour demand and wage structure with respect to different skill groups. These integration effects should be stronger in border regions. Using data from the Czech Microcensus and quarterly district level data, I investigate the impact of the fall of the Iron Curtain on the regional differences in unemployment, the skill structure of employment and wages in the Czech Republic. According to my results there are no indications of disproportionate shifts in the economic structure as well as in the skill structure in the Czech districts neighbouring Bavaria and Austria compared to non-border districts. However, regarding wage differentials between workers employed in the border region and workers in the rest of the country, I find evidence that between 1996 and 2002 the border region workers of the lowest skill category exhibit a positive wage differential of around 12% compared to their counterparts in non-border districts. For all other skill groups in the border region the spatial wage gap is negative and, in absolute value, increases with the skill level." (Author's abstract, IAB-Doku) ((en))osteuropäischer Transformationsprozess - Auswirkungen, Grenzgebiet, EU-Binnenmarkt, europäische Integration, Wirtschaftsstruktur, Wirtschaftsstrukturwandel, Beschäftigtenstruktur, Erwerbstätige, Arbeitslose, Qualifikationsstruktur, Lohnstruktur, regionaler Arbeitsmarkt, Tschechische Republik, Bayern, Bundesrepublik Deutschland, Österreich

The German-Czech Border Region after the Fall of the Iron Curtain : Effects on the Labour Market

Using the IAB Employment Sample (IABS) covering 1980-2001 we investigate what impact the fall of the Iron Curtain has had on the skill structure of employment and wages in the western German districts neighbouring the Czech Republic. The introduction of free trade in this region, which has one of the world´s largest spatial wage differentials, can be seen as a natural experiment. We presume that changes in skill and wage structures are particularly apparent in the regions situated immediately on the open border. Distinguishing three skill categories we obtain unexpected results. Though we observe a general shift from low-skilled jobs towards skilled jobs and a convergence trend of border regions towards the national average, we do not find a special effect for the period after the opening of the border, neither concerning the skill structure nor the wage differentials. -- Unter Verwendung von Daten der IAB-Regionalstichprobe (IABS) untersuchen wir, ob nach dem Fall des Eisernen Vorhangs Qualifizierungstrends und Lohnentwicklung in den bayerischen Grenzregionen zu Tschechien signifikante Unterschiede im Vergleich mit der Entwicklung auf aggregierter staatlicher Ebene aufweisen. Der Trend zu höherer Qualifizierung sowie der Trend zu höheren relativen Löhnen für besser Qualifizierte sollten dort überdurchschnittlich messbar sein. Unsere Resultate können einen speziellen Grenzöffnungseffekt jedoch weder bei der Qualifikationsstruktur noch bei der relativen Lohnentwicklung in der Grenzregion feststellen.border regions,international trade,employment,wage inequality

Analysis of damage and fracture mechanisms in ductile metals under non-proportional loading paths

The paper discusses biaxial experiments and corresponding numerical simulations to analyze the effect of non-proportional loading paths on damage and fracture behavior of ductile metals. Newly developed specimens are taken from thin metal sheets and are tested under different biaxial loading conditions covering a wide range of stress states. In this context, an anisotropic continuum damage model is presented based on yield and damage conditions as well as on evolution laws for plastic and damage strain rates. Different branches of the damage criteria are taken into account corresponding to various damage and failure processes on the micro-level depending on stress triaxiality and Lode parameter. Experiments with biaxially loaded specimens have been performed. Results for proportional and corresponding non-proportional loading histories are discussed. During the experiments strain fields in critical regions of the specimens are analyzed by digital image correlation (DIC) technique while the fracture surfaces are examined by scanning electron microscopy (SEM). Numerical simulations of the experiments have been performed and numerical results are compared with experimental data. In addition, based on the numerical analyses stress distributions in critical parts of specimens are detected. The results demonstrate the efficiency of the new specimen’s geometries covering a wide range of stress states in the shear/tension and shear/compression regime as well as the effect of loading history on damage and fracture behavior in ductile metal sheets

The parameterized space complexity of model-checking bounded variable first-order logic

The parameterized model-checking problem for a class of first-order sentences (queries) asks to decide whether a given sentence from the class holds true in a given relational structure (database); the parameter is the length of the sentence. We study the parameterized space complexity of the model-checking problem for queries with a bounded number of variables. For each bound on the quantifier alternation rank the problem becomes complete for the corresponding level of what we call the tree hierarchy, a hierarchy of parameterized complexity classes defined via space bounded alternating machines between parameterized logarithmic space and fixed-parameter tractable time. We observe that a parameterized logarithmic space model-checker for existential bounded variable queries would allow to improve Savitch's classical simulation of nondeterministic logarithmic space in deterministic space $O(\log^2n)$. Further, we define a highly space efficient model-checker for queries with a bounded number of variables and bounded quantifier alternation rank. We study its optimality under the assumption that Savitch's Theorem is optimal

A quaternion-based model for optimal control of the SkySails airborne wind energy system

Airborne wind energy systems are capable of extracting energy from higher wind speeds at higher altitudes. The configuration considered in this paper is based on a tethered kite flown in a pumping orbit. This pumping cycle generates energy by winching out at high tether forces and driving a generator while flying figures-of-eight, or lemniscates, as crosswind pattern. Then, the tether is reeled in while keeping the kite at a neutral position, thus leaving a net amount of generated energy. In order to achieve an economic operation, optimization of pumping cycles is of great interest. In this paper, first the principles of airborne wind energy will be briefly revisited. The first contribution is a singularity-free model for the tethered kite dynamics in quaternion representation, where the model is derived from first principles. The second contribution is an optimal control formulation and numerical results for complete pumping cycles. Based on the developed model, the setup of the optimal control problem (OCP) is described in detail along with its numerical solution based on the direct multiple shooting method in the CasADi optimization environment. Optimization results for a pumping cycle consisting of six lemniscates show that the approach is capable to find an optimal orbit in a few minutes of computation time. For this optimal orbit, the power output is increased by a factor of two compared to a sophisticated initial guess for the considered test scenario.Comment: 18 pages, 14 figures, submitted to Journal of Applied Mathematics and Mechanics (ZAMM

Spatial effects of open borders on the Czech labour market

Westeuropa hat kaum zur Kenntnis genommen, dass der Fall des Eisernen Vorhangs auch Auswirkungen auf die regionalen Arbeitsmarktstrukturen in den osteuropäischen Ländern hatte. Der Beitrag untersucht, ob die tschechische Grenzregion in unmittelbarer Nähe zu den westeuropäischen Hochlohnländern während der zweifellos zunehmenden Integration der Märkte von ihrer geographischen Lage profitierte. Auch ohne grenzüberschreitende freie Arbeitskräftemobilität kann freier Handel und die Ausgliederung von Produktionsaktivitäten zu Veränderungen bei der Nachfrage nach Arbeit und der Lohnstruktur im Hinblick auf unterschiedlich qualifizierte Gruppen führen. Diese Integrationseffekte können sich in den Grenzregionen stärker auswirken. Der Beitrag untersucht auf der Basis von Daten des tschechischen Mikrozensus und vierteljährlicher aggregierter Daten auf Kreisebene die Auswirkungen des Falls des Eisernen Vorhangs auf regionale Unterschiede bezüglich Arbeitslosigkeit sowie Qualifikations- und Lohnstruktur in der Tschechischen Republik. Die Ergebnisse zeigen, dass es keine Hinweise auf überproportionale Veränderungen in der Wirtschafts- und Qualifikationsstruktur in den an Bayern und Österreich angrenzenden tschechischen Kreisen im Vergleich zu den nicht im Grenzgebiet liegenden Bezirken gab. Wenn man die Lohnunterschiede zwischen Arbeitnehmern in den Grenzregionen und Arbeitnehmern im Rest des Landes betrachtet, zeigt sich, dass zwischen 1996 und 2002 die Beschäftigten in den Grenzregionen mit der niedrigsten Qualifikationsstufe einen positiven Lohnunterschied von rund 12 Prozent im Vergleich zu entsprechenden Beschäftigten im Binnenland aufweisen. Für alle anderen Qualifikationsgruppen in der Grenzregion ist die räumliche Lohnkluft negativ und nimmt in absoluten Zahlen mit ansteigender Qualifikation zu