Publications

Das vorliegende Dissertationsvorhaben besteht aus drei unabhängigen Forschungspapieren, die sich alle mit dem Thema Arbeitskräfteumlauf und Anreizverträge in einem dynamischen Search-und-Matching-Arbeitsmarktmodell beschäftigen. Das grundlegende Modell in diesem Forschungsbereich wurde in den Studien von Diamond, Mortensen und Pissarides entwickelt, die den Einfluss von Suchfriktionen und Produktivitätsschwankungen auf die Mobilität von Arbeitskräften zwischen Beschäftigung und Arbeitslosigkeit untersuchen. Allerdings werden die Arbeitsverträge in diesen Studien in einer sehr vereinfachten Version dargestellt: Insbesondere die Prinzipal-Agent-Probleme sowie die asymmetrische Informationsstruktur zwischen Unternehmen und Arbeitnehmern werden nicht berücksichtigt, und auch die Arbeitgeberbindung zwischen Unternehmen und Arbeitnehmern wird oft nicht ausreichend beachtet. Aus diesem Grund widmet sich diese Dissertation der Untersuchung der Interdependenz zwischen Suchfriktionen am Arbeitsmarkt und Prinzipal-Agent-Problemen aufgrund von asymmetrischen Informationen zwischen Firmen und Arbeitnehmern. Das zentrale Prinzipal-Agent-Problem, das in dieser Dissertation behandelt wird, ist das verborgene Handeln von Arbeitnehmern, welches in Form von Drückebergerei oder der Suche nach einem anderen Arbeitsplatz vorkommt. Um diese Probleme zu beheben benutzen die Firmen Anreizverträge. Die Möglichkeit für Firmen Anreizverträge einzusetzen hat entscheidende Konsequenzen für die Löhne von Arbeitnehmern, die gleichgewichtige Arbeitslosigkeit sowie f¨ur die branchenübergreifende Korrelation zwischen den Arbeitslöhnen, Leistungsprämien, Produktivität und Entlassungsquoten. Die theoretischen Prognosen für die oben genannten Zusammenhänge stimmen mit den Ergebnissen der empirischen Studien überein.
Aus der Perspektive der normativen Analyse befasst sich diese Dissertation mit den Fragen nach optimalem Arbeitslosengeld und der gesamtwirtschaftlichen Wohlfahrt im Kontext von Anreizverträgen. Die Ergebnisse der durchgef¨uhrten Untersuchung zeigen einen negativen Zusammenhang zwischen dem optimalen Niveau der Arbeitslosenversicherung und dem Umfang des Moral-Hazard-Problems in den Unternehmen. Darüber hinaus wird nachgewiesen, dass eine unvollständige Arbeitgeberbindung der Beschäftigten zu einer ineffizient niedrigeren gesamt-wirtschaftlichen Wohlfahrt führen kann.

This thesis is a collection of four stand-alone essays on international competition for human capital, together with a general introduction and some concluding remarks. The first essay deals with decentralized public education and human capital mobility. The international mobility of highly-skilled workers may result in an underinvestment in local public higher education when national entities independently decide on educational expenditures to maximize local output. This well-established result due to a positive interregional spillover of national educational policy when some individuals emigrate after graduating can reverse if student mobility is taken into account. When local educational policy attracts foreign students, a negative spillover takes place, and the actual discrepancy between decentralized policy and the global-output-maximizing solution depends on the relative sizes of the two spillovers. The paper also presents a variant of this model in which local governmental objectives rest exclusively upon the native population. The second essay analyzes the effect of increasing human-capital mobility - i.e., student and labor mobility - on net tax revenues when revenue-maximizing governments compete for human capital by means of income tax rates as well as amenities offered to students (positive expenditure) or by tuition fees (negative expenditure). An increase in labor mobility results neither in an intensified tax competition nor an erosion of revenues. In fact, the equilibrium tax rate even increases with labor mobility. Amenities offered to students are non-monotonically related to labor mobility; overall, net revenues increase with labor mobility. An increase in student mobility, however, erodes revenues, mainly due to intensified tax competition. A concurrent cutback in expenditures mitigates this erosion but cannot fully prevent it. The third essay presents a model of student migration in order to determine the optimal level of non-resident tuition fees in a host country of higher education. Students with rational expectations consider a potential return migration in their first-round decision of whether to study abroad, so that demand for the higher-educational system in the host country and optimal non-resident tuition fees depend on the stay rates of foreign-born graduates. A decline in stay rates of foreign students is demonstrated to lead to a cutback in optimal tuition fees if the cost of education per student is not too high. The fact that students take into account the possibility of return migration after graduation in their first-stage location decision, in combination with rational expectations, finally produces this result. The fourth essay presents a model of two countries competing for the international pool of talented students from the rest of the world. To relax tuition-fee competition, countries differentiate their educational systems in equilibrium. While one country offers high educational quality at high rates for students -- the most talented choose to study in this country -- the other provides lower quality and charges lower tuition fees. The regional quality-differentiation increases with the size of the international talent pool, with the stay rate of foreign students in the host countries after graduating, and with the degree of development of the home countries of the foreign students. In comparison to the welfare-maximizing educational policy, the decentralized solution is likely to result in an inefficient allocation of foreign students to the two host countries, as well as an inefficient quality differentiation.

This dissertation is a collection of three stand-alone research papers written as part of the doctoral program in Quantitative Economics and Finance at the University of Konstanz during my time as a research assistant at the University of Vienna.
The focus of previous research on entrepreneurship has been almost exclusively on solo entrepreneurs and their individual characteristics and behaviors (Gartner, 1988; Birley and Stockley, 2000). The number of studies using teams as the unit of analysis is small (Davidsson and Wiklund, 2001; Chowdhury, 2005). And remarkably little attention has been paid to teams during the time that they are engaged in the entrepreneurial organizing activities. However, a large proportion of all newly founded ventures are started by teams (Ruef, Aldrich, and Carter, 2003). The literature on organizational and team behavior acknowledges the importance of team composition for business outcomes. The complex interactions among team members affect the behavior of each individual team member and therefore the performance of the team as a whole (e.g. Williams and O Reilly, 1998). Accordingly, results from previous studies on solo entrepreneurs who create start-ups are not transferable to teams that do the same thing. This dissertation closes a gap in research on start-up teams while they are engaged in the process of creating new businesses. The present section provides a brief introduction to the following chapters and summarizes the main results.
Chapter 1 is based on the research paper Formation of Nascent Entrepreneurial Teams: What Role Does the Level of Human Capital Play? and analyzes the composition of nascent entrepreneurial teams according to individual levels of human capital. Classic human capital theory and signaling theory both posit a positive relationship between human capital and the successful completion of entrepreneurial organizing activities. The empirical analyses confirm these theoretical insights by indicating a highly significant positive relationship between the levels of human capital in entrepreneurial teams and the probability of completing the process of new business creation. Upon this finding, this chapter builds two other insights on how nascent entrepreneurial teams are built, based on human capital levels of potential co-founders. The first insight is that nascent entrepreneurs look for cofounders whose level of human capital is very close to theirs. The second contribution is that the heterogeneity in human capital levels within start-up teams derives primarily from co-founders who have close social ties, such as relatives.
Chapter 2 originated as a research paper written together with Dr. Christian Hopp (University of Vienna) and entitled Entrepreneurial Team Composition: It s Not Just What You Know, but also How Long You ve Known the Co-Founders! This chapter analyzes the compositions of start-up teams, and finds that persistent heterogeneity in levels of human capital is accompanied by high levels of social cohesion; considerations such as trust and shared understanding may be as important as pure human capital. Human and social capital cannot substitute for each other, but rather, the founder who exhibits a higher level of human capital satisfies the social capital needs for the new venture by enlisting members of his own social network. Individuals of higher ability also provide greater amounts of financial capital. This corroborates the observation that founders can strengthen their role within the venture by aligning managerial inputs with potential financial rewards and decision-making rights.
Chapter 3 comes from the research paper Understanding the Dynamics of Nascent Entrepreneurship: Is It What You Know, or What You Do, or Both?, another joint project with Dr. Hopp. This study analyzes the determinants underlying the process of creating a new business. It examines whether several elements of nascent entrepreneurs human capital - formal education, labor market experience, and entrepreneurial experience - influence the rate of accomplishing the entrepreneurial activities, the tendency to concentrate these activities, and the overall timing of start-up activities. Moreover, the design of the founding process of new ventures and the level of human capital of the nascent entrepreneurs are linked with the likelihood of success. The results provide strong evidence that the most valuable type of human capital for new venture emergence is high task-related knowledge, such as entrepreneurial or labor market experience, while human capital has neither a direct nor indirect effect on the likelihood of successful venture creation when it consists of low task-related knowledge such as formal education.

Diese Dissertation untersucht die Messung finanzieller Risiken und besteht aus vier eigenständigen Forschungspapieren über die Analyse, Modellierung und Vorhersage solcher Risiken in verschiedenen wirtschaftlichen Szenarien. Die gegenwärtigen Risikomaße ignorieren größtenteils das systematische Risiko, das durch Korrelationen von Finanzanlagen, Finanzmärkten oder Finanzinvestoren induziert wird und sind in zunehmendem Maße Modellrisiken ausgesetzt, die infolge von falschen Modellspezifikationen, Schätzrisiken oder Messfehlern entstehen. Vor diesem Hintergrund versucht diese Arbeit, die Risiken in der Messung finanzieller Risiken ausführlich zu analysieren. Darüber hinaus wird versucht, neue Ansätze zu entwickeln, welche hinreichend genau die systematischen Zusammenhänge zwischen verschiedenen finanziellen Variablen messen und den Einfluss von Modellrisiken auf die Präzision von daraus resultierenden Risikomodellen minimieren.

Nationalökonomien und ihre Verschuldung sind eigentlich unüberschaubar. Am Beispiel sogenannter Entwicklungs- und Schwellenländer zeigt dieses Buch, wie Regierungen und internationale Finanzinstitutionen sich dennoch tagtäglich Übersicht verschaffen: Mithilfe spezifischer Beobachtungstechnologien können weit verstreute Daten in kompakte, ständig reprojizierbare Zahlengestalten transformiert werden.
Barbara Grimpe legt dar, dass die Leistungsfähigkeit dieser »skopischen Systeme« allerdings von der veränderlichen Wissenskultur einer vielstimmigen transnationalen Gemeinschaft von Schuldenexperten abhängt. Es wird deutlich, wie kulturell und historisch voraussetzungsvoll es ist, nationale Verschuldung auf kleinstem Raum begreifbar zu machen.