This thesis covers three issues: the aggregate and welfare effects of environmental policies when plants are heterogeneous; what causes the different patterns of employment dynamics in small versus large firms over business cycles; and the welfare costs of expected and unexpected inflation. In the first chapter, we show that accounting for plant heterogeneity is important for the evaluation of environmental policies. We develop a general equilibrium model in which monopolistic competitive plants differ in productivity, produce differentiated goods and choose optimally a discrete emission-reduction technology. Emission-reduction policies affect both the fraction of plants adopting the advanced emission-reduction technology and the market shares of those with high levels of productivity. Calibrated to the Canadian data, the model shows that the aggregate costs of an emission tax to implement the Kyoto Protocol are 40 percent larger than the costs that would result with homogenous plants. In the second chapter, we incorporate labor search frictions into a model with lumpy investment to explain a set of firm-size-related facts about the United States labor market dynamics over business cycles. Contrary to the predictions of standard models, we observe that job destruction is procyclical in small firms but countercyclical in large ones. Calibrated to U.S. data, the model generates this asymmetric pattern of employment dynamics in small versus large firms. This is because a favorable aggregate productivity shock tightens the labor market. A tighter labor market hurts investing small firms. As a result, workers move from small to large firms during booms. In the third chapter, we analyze the welfare costs of inflation when money is essential to facilitate trades among anonymous agents and information about nominal shocks is incomplete as in Lucas (1972). In the model, the transactions in which money is essential coincide with those in which agents are affected by monetary shocks. Consequently, the average value of money and its variation in value in different markets affect agents simultaneously when the supply of money changes. Calibrated to U.S. data, we find that the welfare costs of expected inflation are almost three orders higher than the welfare costs of unexpected inflation.

This thesis covers three issues: the aggregate and welfare effects of environmental policies when plants are heterogeneous; what causes the different patterns of employment dynamics in small versus large firms over business cycles; and the welfare costs of expected and unexpected inflation. In the first chapter, we show that accounting for plant heterogeneity is important for the evaluation of environmental policies. We develop a general equilibrium model in which monopolistic competitive plants differ in productivity, produce differentiated goods and choose optimally a discrete emission-reduction technology. Emission-reduction policies affect both the fraction of plants adopting the advanced emission-reduction technology and the market shares of those with high levels of productivity. Calibrated to the Canadian data, the model shows that the aggregate costs of an emission tax to implement the Kyoto Protocol are 40 percent larger than the costs that would result with homogenous plants. In the second chapter, we incorporate labor search frictions into a model with lumpy investment to explain a set of firm-size-related facts about the United States labor market dynamics over business cycles. Contrary to the predictions of standard models, we observe that job destruction is procyclical in small firms but countercyclical in large ones. Calibrated to U.S. data, the model generates this asymmetric pattern of employment dynamics in small versus large firms. This is because a favorable aggregate productivity shock tightens the labor market. A tighter labor market hurts investing small firms. As a result, workers move from small to large firms during booms. In the third chapter, we analyze the welfare costs of inflation when money is essential to facilitate trades among anonymous agents and information about nominal shocks is incomplete as in Lucas (1972). In the model, the transactions in which money is essential coincide with those in which agents are affected by monetary shocks. Consequently, the average value of money and its variation in value in different markets affect agents simultaneously when the supply of money changes. Calibrated to U.S. data, we find that the welfare costs of expected inflation are almost three orders higher than the welfare costs of unexpected inflation.

Based on an individual longitudinal data on dependent employment we analyse the role of Creative Industries for the employment system of Vienna. We focus on gross job flows and firm dynamics in this priority field of Vienna's urban policy and analyse the characteristics of the different parts of the cluster's production system. We find ample evidence for positive effects of Creative Industries on employment growth and firm birth, but also reveal considerable job turnover and a large heterogeneity of firm growth in the cluster. Especially, we find rather different evolutions along the clusters value chain, which points to weak linkages between upstream and downstream activities in the cluster. (author's abstract) / Series: Creative Industries in Vienna: Development, Dynamics and Potentials

The main focus of this thesis is the employment decisions of firms. The thesis consists of three self-contained but closely related essays, all enlightening employment dynamics in different ways. The thesis is mainly empirical but there are also some theoretical developments when existing theory is insufficient to explain the empirical findings. The impact on employment of product market conditions and labor market conditions facing firms are investigated. The results suggest that product demand has a robust impact on firms’ employment dynamics, but also the market price, the wage costs, and the matching between vacancies and unemployed workers seem to matter. The empirical evidence of the relevance of imperfect competition in the product market is important, particularly since most research on labor market dynamics has assumed perfect competition. The results with respect to matching of vacancies and unemployed workers contradict the standard search and matching model as well as simple efficiency-wage or bargaining models with wage rigidity and excess supply but no frictions in the labor market. A richer model of the labor market is needed to explain the results, including on-the-job search and perhaps more heterogeneity between employed and unemployed workers. Essay I, “What are the Determinants of Hiring? - The Role of Demand and Supply Factors”, studies the importance of demand and supply factors for hiring in local labor markets. Essay II, “Vacancy Matching and Labor Market Conditions”, studies the probability of filling a vacancy, how it varies with the number of unemployed and the number of vacancies in the local labor market, and what impact it has on firms’ employment dynamics. Essay III, “The Dynamics of Firms’ Factor Demand”, studies firm-level adjustments of employment, the capital stock, and inventories in response to exogenous shocks theoretically and empirically. These three decisions have typically been studied one at the time, but here they are studied together in a way which allows for interactions and a better understanding of firm behavior.

Cette thèse de doctorat porte sur la dynamique de l’emploi dans les entreprises et sur la relation entre la dynamique de l’emploi et l’innovation, avec une attention particulière portée sur les entreprises nouvellement créées. Cette thèse conceptualise théoriquement et analyse empiriquement les différents aspects de l’interaction complexe entre le changement technologique et la dynamique de l’emploi, en se concentrant sur les effets hétérogènes des différents types d’innovation sur la croissance de l’emploi. Compte tenu le rôle primordial joué par les nouvelles et jeunes entreprises dans le processus de destruction créatrice et leur apport à la création globale de l’emploi, cette thèse fournit une caractérisation de la contribution nette d’emplois des nouvelles entreprises dans un nombre important de pays, en utilisant des données micro-agrégées issues d’une nouvelle base de données. En outre, elle analyse comment un certain nombre de caractéristiques institutionnelles affectent la création nette d’emplois dans les start-ups, en se concentrant sur les effets hétérogènes des politiques sur les nouvelles entreprises et les entreprises déjà existantes. Cette thèse étudie enfin une caractéristique particulière des lois de distribution des taux de croissance de l’emploi, c’est-à-dire la volatilité de la croissance de l’emploi, que non seulement se révèle être une médiation cruciale des effets des politiques sur la création nette d’emplois, mais a aussi d’importantes implications à la fois micro- et macroéconomiques. / This doctoral thesis focuses on employment dynamics in firms, and on the relationship between employment dynamics and innovation, with a particular focus on the entry process. It conceptualizes theoretically and analyses empirically different aspects of the complex interaction between technical change and employment dynamics, focusing on the heterogeneous effects of different types of innovation on employment growth. In the light of the prominent role of newly-born firms in shaping the creative destruction process and contributing to overall job creation, this thesis provides a characterization of the net job contribution by surviving entrants across a significant number of countries. Using newly collected representative micro-aggregated data, it further analyses whether and how a number of institutional characteristics affect start-ups’ net job creation, focusing on the heterogeneous effects of policies on entrants and incumbents. This thesis finally characterizes a particular feature of the employment growth distributions – employment growth volatility – that not only proves to be crucially mediating the effects of policies on entrants’ net job creation, but also has important micro and macroeconomic implications.