Climate change projections show that the average global temperature will very likely increase further. Policymakers need to implement suitable mitigation policy measures. This thesis uses dynamic general equilibrium models (DGEs) to analyse the potential economic effects of mitigation policy. Chapter 2 documents the forecasting performance of standardly estimated macroeconomic models and compare them to extended versions. It turns out that neither alternative expectation formation behaviour nor financial frictions can systematically increase the forecasting performance of macroeconomic models. Chapter 3 studies potential economic consequences of a coal phase-out in Germany, using a spatial dynamic general equilibrium model. A phase-out until 2035 is not worse in terms of welfare compared to a coal exit until 2040. Chapter 4 develops a dynamic stochastic general equilibrium (DSGE) model with risky capital and oil as production factors. The contribution of financial market frictions and oil market disturbances to the US business cycle are low. An oil tax increase, to reduce crude oil consumption by 10% can cause a contraction of GDP by 1 to 2%.

The three papers reprinted in chapters 3 to 5 of this cumulative dissertation thesis investigate the effectiveness of European competition law and whether its main objective – to ensure a fair competition between companies – can be reached. Yet, competition is expected to maximize welfare as it forces companies to reduce prices or to improve their quality or service. However, competition can be distorted if companies agree with each other to fix prices, or if a company with a dominant market position uses its dominance to distort competition. Another possible threat to competition might come to the fore if a merger among large companies reduces competition or if governmental support to a specific company leads to an advantage over its competitors. Therefore, in order to ensure a fair competition among companies governments normally do not intervene in the process but set only the framework in which businesses operate. European competition policy as part of this regulatory policy includes all measures aimed at preserving competition and comprises four main pillars: Cartel law, Antitrust law, Mergers and Acquisitions and State Aid. The papers of this thesis focus on two of these four areas: Cartels and State Aid.

A frequent criticism of GDP states that events that obviously reduce welfare of people can nevertheless increase GDP per capita. We use data of natural disasters as quasi experiments to examine whether alternatives to GDP (Human Development Index, Progress Index, Index of Economic Well-Being and a Happiness Index) lead to more plausible responses to disasters. Applying a Differences-in-Differences approach and estimates from various panels of countries we find no noteworthy differences between the response of real GDP per capita and the responses of suggested alternative welfare measures to a natural disaster except for the Human Development Index.

Using data from the OECD Regional Well-Being Index – a set of quality-of-life indicators measured at the sub-national level, we construct a set of composite well-being indices. We analyse the extent to which the choice of five alternative aggregation methods affects the well-being ranking of regions. We find that regional inequality in these composite measures is lower than regional inequality in gross-domestic product (GDP) per capita. For most aggregation methods, the rank correlation across regions appears to be quite high. It is also shown that using alternative indicators instead of GDP per capita would only have a small effect on the set of regions eligible for aid from EU Structural Funds. The exception appears to be an aggregation based on how individual dimensions of welfare relate to average life satisfaction across regions, which would substantially change both the ranking of regions and which regions would receive EU funds.

We discuss properties of alternatives or complements to GDP as a measure of welfare at business cycle frequencies. Our results imply that the suggested indicators show practically no cycle at all and their methodologies can be questioned. First, data are not available at an appropriate quality and frequency. Second, the suggested time series sometimes correlate negatively with each other. Third, cross-section and quasi-panel evidence based on different samples of countries reveals no impact of the stance of the business cycle on some suggested welfare measures. Therefore, alternative welfare measures do not show an equal picture on business cycle frequencies compared to GDP-based measures.

This interim report summarises the main findings of the Competitiveness Research Network (CompNet) after one year of existence. The Network is organized in three workstreams related to: (i) aggregate measures of competitiveness; (ii) firm-level studies; and (iii) global value chains (GVCs). The main objectives of the Network are to improve the existing frameworks and indicators of competitiveness across all dimensions (macro, micro and cross-border) and establish a more solid connection between identified competitiveness drivers and resulting outcomes (trade, aggregate productivity, employment, growth and essentially welfare), in order to support the design of adequate policies.

Greater openness for trade can have positive welfare effects in terms of higher growth. But increased openness may also increase uncertainty through a higher volatility of employment. We use regional data from Germany to test whether openness for trade has an impact on volatility. We find a downward trend in the unconditional volatility of employment, paralleling patterns for output volatility. The conditional volatility of employment, measuring idiosyncratic developments across states, in contrast, has remained fairly unchanged. In contrast to evidence for the US, we do not find a significant link between employment volatility and trade openness.

This article assesses whether the economy of East Germany is catching up with the West German region in terms of welfare. While the primary measure for convergence and catching up is per capita output, we also look at other macroeconomic indicators such as unemployment rates, wage rates and production levels in the manufacturing sector. In contrast to existing studies of convergence between regions of the reunified Germany, our approach is based purely upon the time series dimension and is thus directly focused on the catching up process in East Germany as a region. Our testing set-up includes standard ADF unit root tests as well as unit root tests that endogenously allow for a break in the deterministic component of the process. We find evidence of catching up for East Germany for most of the indicators. However, the convergence speed is slow, and thus it can be expected that the catching up process will take further decades until the regional gap is closed.

We discuss how the welfare ranking of fixed and flexible exchange rate regimes in a New Open Economy Macroeconomics model depends on the interplay between the degree of exchange rate pass-through and the elasticity of substitution between home and foreign goods. We identify combinations of these two parameters for which flexible and fixed exchange rates are superior with respect to welfare as measured by a representative household's utility level. We estimate the two parameters for six non-EMU European countries (Czech Republic, Hungary, Poland, Slovakia, Sweden, and the UK) using a heterogeneous dynamic panel approach.

This paper assesses whether the economy of East Germany is catching up with the

West German region in terms of welfare. While the primary measure for convergence and catching up is per capita output, we also look at other macroeconomic indicators such as unemployment rates, wage rates, and production levels in the manufacturingsector. In contrast to existing studies of convergence between regions of reunified Germany, our approach is purely based upon the time series dimension and is thus directly focused on the catching up process in East Germany as a region. Our testing setup includes standard ADF unit root tests as well as unit root tests that endogenously allow for a break in the deterministic component of the process. In our analysis, we find evidence of catching up for East Germany for most of the indicators. However, convergence speed is slow, and thus it can be expected that the catching up process will take further decades until the regional gap is closed.