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The ambitious late Gothic vaults created in the 15th and 16th centuries with their complex shape and complicated meshes of ribs soaring along spatial curves, were extremely demanding in their geometric design. This regards both the design of the whole structure, as also the design specifications for the single stone elements which were prefabricated and fit together on the building site with astonishing precision. In consequence, the particular character of these structures and their geometric features are intrinsically linked to the design routines and the geometric concepts used by the Master Builders. At present, these procedures and methods are not well understood, because they are not documented in original drawings, and because they differ in principle from the modern practice. In consequence, necessary works of repairing and restoring cannot recur to any information related to the original design. Moreover, understanding the characteristics of information transfer from the design to the execution, would cast a light on the information society in which these constructions were created. In several case studies, the geometric concepts of the intricate spatial curve systems of late Gothic vaults have been clarified on the basis of detailed surveys and geometrical analyses carried out on the built objects. On this background, also the existing sources such as historical design treatises could be re-interpreted. In a collaboration between the research group working on the design principles of late Gothic vaults at the Technische Universität Dresden, and expert stone masons specialized on historical working techniques and practical stereotomy at the Cathedral Workshop Œuvre Notre-Dame de Strasbourg, the phases of the design process, such as full-scale drawings on the tracing floor and the production of full-scale models and samples of ribs and keystones, are currently investigated in practical experiments. As result, we propose a complete picture of the design process from the general concept to the setting-out of the single stone elements. Further, we are able to drive general considerations on the Late Medieval and Early Modern design practice for stone structures and trace a new interpretation of the early treatises of stereotomy.

Diese Dissertation umfasst drei Aufsätze, von denen sich die ersten beiden mit dem Phänomen der beruflichen Mobilität von Arbeitnehmern im westdeutschen Arbeitsmarkt befassen. Der erste Aufsatz untersucht für Absolventen einer dualen Berufsausbildung die kausalen Lohneffekte von Mobilität über Firmen und Berufe hinweg. Die Instrumentenvariablenschätzungen, welche exogene Variation in regionalen Arbeitsmarktcharakteristika ausnutzen, zeigen, dass Berufswechsel innerhalb des Ausbildungsbetriebs einen Karrierefortschritt darstellen. Bei Jobwechseln dominiert der Verlust von firmenspezifischem Humankapital. Allerdings nimmt der Lohnverlust nicht weiter zu, wenn zusätzlich zur Firma auch der Beruf gewechselt wird. Angesichts dieser Ergebnisse dokumentiert der zweite Aufsatz Muster von beruflicher Mobilität in Westdeutschland über den Zeitraum 1982--2008 innerhalb von und zwischen Firmen. Die Häufigkeit von beruflicher Mobilität hat seit 1982 zwischen Firmen signifikant zugenommen und innerhalb von Firmen signifikant abgenommen. Die Analyse betrachtet zudem mögliche Erklärungsansätze für diese Entwicklungen, wie zum Beispiel den demografischen Wandel oder den Zusammenhang zwischen beruflicher Mobilität und Arbeitslosigkeit. Der dritte Aufsatz untersucht den Zusammenhang zwischen Produktmarktderegulierung und Arbeitsmarktergebnissen. Die Reform der deutschen Handwerksordnung von 2003 wird als natürliches Experiment genutzt, um mögliche Einflüsse der Abschaffung von Markteintrittsbarrieren auf selbstständige und abhängige Beschäftigung zu untersuchen. Da Zweifel an der Gültigkeit der identifizierenden Annahmen aufkommen, können die Schätzergebnisse nicht kausal interpretiert werden. Dennoch legen die Ergebnisse zumindest in Teilen nahe, dass der in der Literatur bereits dokumentierte positive Effekt auf selbstständige Beschäftigung plausibel ist, wohingegen die Reform vermutlich keinen Anstieg der abhängigen Beschäftigung in den deregulierten Berufen zur Folge hatte. / This thesis comprises three essays, out of which the first two study the phenomenon of worker mobility across occupations in the West German labor market. The first essay studies the causal wage effects of mobility across firms and occupations among graduates from apprenticeship training. Exploiting variation in regional labor market characteristics the instrumental variables estimations indicate that occupation switches within the training firm involve a career progression. For job switches the loss of firm-specific human capital seems to dominate. However, the wage loss does not grow when an occupation switch occurs simultaneously. In light of these results, the second essay in this thesis studies patterns of occupational mobility in West Germany over the period 1982--2008 separately within and across firms. Most importantly, occupational mobility rates across firms have significantly increased since the early 1980s, while within-firm occupational mobility rates have significantly decreased. The essay also assesses potential explanations for these developments, such as demographic change or the relationship between occupational mobility and unemployment. The third essay in this thesis studies the relationship between product market deregulation and labor market outcomes. It exploits the 2003 reform of the German Crafts Code as a natural experiment to study how the abolishment of barriers to firm entry may affect self-employment and dependent employment. Since there are doubts regarding the validity of the identifying assumptions, the results cannot be interpreted causally. Nevertheless, the analysis at least partially corroborates the evidence for a positive reform effect on self-employment documented elsewhere in the literature, while the reform seems not to have had a positive effect on dependent employment in the deregulated crafts occupations.