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Recently polyfluoroalkyl compounds (PFCs) were discovered as emerging persistentorganic pollutants. Because of their unique physicochemical properties due to theircombination of lipophilic and hydrophilic characteristics, PFCs have been widely used inmany consumer products, such as polymerisation aids, stain repellents on carpets, textiles, andpaper products for over 50 years. From the production and use of these products, PFCs can bereleased into the environment. Scientific concern about PFCs increased due to their globaldistribution and ubiquitous detection in the environment, especially in marine mammals.An analytical protocol was developed for the analysis of PFCs in water samples andvarious biological matrices. The samples were analysed for 40 PFCs plus 20 isotope-labelledinternal standards using high performance liquid chromatography/negative electrosprayionisation-tandem mass spectrometry (HPLC/(-)ESI-MS/MS). Furthermore, the analyticalquality of the laboratory has been approved in interlaboratory studies.In the first part of this Ph.D. thesis was investigated the occurrence, distribution patternand transportation mechanisms of PFCs in seawater. The rivers had a high influence on thedistribution of PFCs in offshore surface water in the German Bight, with decreasingconcentrations with increasing distance from the coast (see publication I). The research onthe spatial distribution of PFCs in coastal area is very important for the understanding of thetransportation and fate of PFCs in the marine environment. Furthermore, the longitudinal andlatitudinal distribution of PFCs in surface water of the Atlantic Ocean was investigated (seepublication II). The results indicate that trans-Atlantic Ocean currents caused the decreasingconcentration gradient from the Bay of Biscay to the South Atlantic Ocean and theconcentration drop-off close to the Labrador Sea. These data are very useful for globaltransportation models, in which industrial areas are considered as sources, and ocean watersas sinks of PFCs.The second part of this Ph.D. thesis examined the mechanisms and pathways of PFCs inharbor seals (Phoca vitulina) and their temporal trends in the German Bight. Firstly, thewhole body burden of PFCs and their tissue distribution (i.e., liver, kidney, lung, heart, blood,brain, muscle, thyroid, thymus, and blubber) was investigated in harbor seals (seepublication III). This study is relevant for calculation of the bioaccumulation potential ofthese compounds in marine mammals. Secondly, the temporal trends over the last decade andassociations between PFC concentration and the evidence of diseases, spatial distribution, ageand sex were evaluated in archived harbor seal livers (see publication IV). The results showsignificant declining concentrations of many PFCs indicating the replacement of these PFCsby shorter chained and less bioaccumulative compounds.Several studies were performed besides the main issue of the Ph.D. work. Firstly, watersamples were collected along the river Elbe into the North Sea to examine the distribution ofPFCs in the dissolved and particulate phase, their discharge into the North Sea, and theinfluence of waste water treatment plant effluents to the riverine mass flow. Furthermore,surface water samples were collected in the North Sea, Baltic Sea and Norwegian Sea, wherethe occurrence and spatial distribution between river estuaries, coastal waters, in brackish aswell as salt water, and open sea water were compared. Finally, within the frame of a researchstay at the National Institute of Advanced Industrial Science and Technology (AIST) in Japan,the partitioning behaviour of PFCs between pore water and sediment in two sediment coresfrom Tokyo Bay was investigated.This Ph.D. thesis has improved our knowledge of the occurrence and distribution of PFCsin water and biota highlighting association between PFCs and pathological conditions,potential sources and sinks, spatial distribution, and changes in their pattern and long-termperspective trends.
All of the papers contained in this thesis deal with some aspect of labor market inequality. The impact of September 11th, 2001 on the employment prospects of Arabs and Muslims in the German labor market (chapter 2) examines whether the attacks on the World Trade Center and the Pentagon on September 11th, 2001 have influenced the job prospects of persons from predominantly Muslim countries in the German labor market. Using a large, representative database of the German working population, evidence from regression-adjusted difference-in-differences-estimates indicates that 9/11 did not cause a severe decline in job prospects. This result, which is in line with prior evidence from Sweden and England, is robust over a wide range of control groups. Islamistic terror and the job prospects of Arab men in Britain: Does a country's direct involvement matter? (chapter 3) examines whether the labor market prospects of Arab men in England are influenced by recent Islamistic terrorist attacks. We use data from the British Labour Force Survey from Spring 1999 to Winter 2006 and treat the terrorist attacks on the USA on September 11th, 2001, the Madrid train bombings on March 11th, 2004 and the London bombings on July 7th, 2005 as quasi-experimental events that may have changed the attitudes towards Arab or Muslim men. Using treatment group definitions based on ethnicity, country of birth and religion, evidence from difference-in-differences-estimators combined with matching indicates that the real wages, hours worked and employment probabilities of Arab men were unchanged by the attacks. This finding is in line with prior evidence from Europe. Effects of the obligation to employ severely disabled workers - findings from the introduction of the Law to Combat Unemployment among Severely Disabled People'' (chapter 4) uses new administrative data from the German Federal Employment Agency -- the Integrated Employment Biographies Sample IEBS -- to assess the impact of a mandatory employment quota for disabled workers in Germany. We use an exogenous change, introduced through the Law to Combat Unemployment among Severely Disabled People'' (Gesetz zur Bekämpfung der Arbeitslosigkeit Schwerbehinderter''), as a natural experiment and measure the change in the reemployment probability of the unemployed disabled by means of regression-adjusted difference-in-differences estimators. Our results indicate that the change in the employment quota neither enhanced nor worsened the employment prospects of the disabled. Finally, Intra-firm wage inequality and firm performance -- First evidence from German linked employer-employee-data (chapter 6) deals with the impact of wage inequality on firm performance. Economic theory suggests both positive and negative relationships between intra-firm wage inequality and productivity. This paper contributes to the growing empirical literature on this subject. We combine German employer-employee-data for the years 1995-2005 with inequality measures using the whole wage distribution of a firm and rely on panel-instrumental variable estimators to control for unobserved heterogeneity and simultaneity problems. Our results indicate a relatively small impact of wage inequality on firm performance in West Germany, while there seems to be a relationship for some inequality measures in East Germany. Further analysis shows that the relationship varies strongly with industrial relations in East Germany.
In the early 1990s the European Commission and the national governments of the EU member states initiated an extensive deregulation and liberalization process in the European railway industry. Prior to this process, the European railway industry was characterized by loosely connected national monopoly railway companies which faced severe losses of transportation market share and required increasing subsidies. Overall, this system was not what a single European market needed: an integrated transport system that provides reliable and fast cross-border transportation of goods, services, and people. The main elements of the reforms have been the separation of infrastructure management from transport operations, the implementation of interoperability among the national railway systems, the assurance of third-party access to the infrastructure, and the introduction of independent railway regulatory systems. In general, the intention of the reforms has been to enhance competition by opening the market and to improve the economic performance of the European railway industry. The objective of this thesis is to analyze the effectiveness of the European railway deregulation process in enhancing efficiency and productivity in the European railway industry. For that purpose three empirical papers are introduced that use non-parametric and parametric benchmarking methods to evaluate the impact of different production technologies and country- and firm-specific environmental and regulatory conditions on efficiency and productivity. The first paper, ‘Testing for Economies of Scope in European Railways: An Efficiency Analysis’, conducts a pan-European efficiency analysis to investigate the performance of European railways with a particular focus on economies of vertical integration. We test the hypothesis that integrated railways realize economies of scope and, thus, produce railway services with a higher level of efficiency. To determine whether joint or separate production is more efficient, we apply an innovative two-stage data envelopment analysis super-efficiency model which relates the efficiency for integrated production to a reference set consisting of separated firms which use a different production technology. We find that for a majority of European railways economies of scope exist. The second paper, ‘Productivity Growth in European Railways: Technological Progress, Efficiency Change and Scale Effects’, analyzes the efficiency and productivity of the European railway sector in the period of deregulation (1990-2005). Using a stochastic frontier panel data model that controls for unobserved heterogeneity a distance function model is estimated in order to evaluate the sources of productivity growth: technological progress, technical efficiency change and scale effects. The results indicate that technology improvements were by far the most important driver of productivity growth, followed by gains in technical efficiency, and to a lesser extent by exploitation of scale economies. Overall, we find an average productivity growth of 39 percent within the sample period. The third paper, ‘European Railway Deregulation: The Influence of Regulatory and Environmental Conditions on Efficiency’, investigates the impact of regulatory and environmental conditions on technical efficiency of European railways. Using a panel data set of 31 railway firms from 22 European countries from 1994 to 2005, a distance function model, including regulatory and environmental factors, is estimated using stochastic frontier analysis. The results obtained indicate positive and negative efficiency effects of different regulatory reforms. Furthermore, estimating models with and without regulatory and environmental factors indicates that the omission of environmental factors, such as network density, substantially changes parameter estimates and, hence, leads to biased estimation results. The last chapter of the thesis summarizes the results of the three empirical analyses. It contains overall conclusions, highlights implications for economic policy, and provides directions for further research.
The present work introduces four theoretical papers, which primarily focus on R&D, interindustrial linkages, and their policy implications. All in all, three issues basically motivated conception and realization: At first, previous NEG models do not incorporate endogenous R&D activities of firms. Existing models include R&D only in a growth context, which increases the formal complexity and departs from the simple core-periphery formulation. Second, vertical linkages are extensively considered in the class of international models. In face of its formal simplicity, the majority of publications refer to the standard model of Krugman and Venables (1995) utilizing intra-industry trade in which the manufacturing sector produces its own intermediates. However, the results are similar to the core-periphery model, but the implications of vertical linkages, especially in terms of specialization, cannot be reproduced. In contrast, the more challenging version of Venables (1996), which considers an inter-industry framework of an explicit upstream and downstream sector, is often cited (143 citations according to IDEAS/RePEc), but only few papers were directly built on it: Puga and Venables (1996), Amiti (2005), Alonso-Villar (2005). The third issue concerns the calibration of real economies. Although, hundreds of numerical simulations have been done in order to display the modeling outcomes, an application to particular industries in terms of their spatial formation and evolution is still a neglected field of research. Against this background, the present work aims to make a contribution to these topics. For a summary, all four papers are briefly to be summarized at this point. The first paper, entitled 'Too Much R&D? – Vertical Differentiation and Monopolistic Competition,' discusses whether product R&D in developed economies tends to be too high compared with the socially desired level. In this context, a model of vertical and horizontal product differentiation within the Dixit-Stiglitz (1977) framework of monopolistic competition is set up where firms compete in horizontal attributes of their products, and also in quality that can be controlled by R&D investments. The paper reveals that in monopolistic-competitive industries, R&D intensity is positively correlated with market concentration. Furthermore, welfare and policy analysis demonstrate an overinvestment in R&D with the result that vertical differentiation is too high and horizontal differentiation is too low. The only effective policy instrument in order to contain welfare losses turns out to be a price control of R&D services. The main contribution of this closed economy model in the course of the present work is a modeling framework, which can easily be adapted to the New Economic Geography. This has been approached in the second paper: ‘R&D and the Agglomeration of Industries' in which the seminal core-periphery model of Krugman (1991) is extended by endogenous research activities. Beyond the common ‘anonymous' consideration of R&D expenditures within fixed costs, this model introduces vertical product differentiation, which requires services provided by an additional R&D sector. In the context of international factor mobility, the destabilizing effects of a mobile scientific workforce are analyzed. In combination with a welfare analysis and a consideration of R&D promoting policy instruments and their spatial implications, this paper also makes a contribution to the brain-drain debate. In contrast to this migration based approach, the third paper 'Agglomeration, Vertical Specialization, and the Strength of Industrial Linkages' focuses on vertical linkages in their capacity as an additional agglomeration force. The paper picks up the seminal model of Venables (1996) and provides a quantifying concept for the sectoral coherence in vertical-linkage models of the New Economic Geography. Based upon an alternative approach to solve the model and to determine critical trade cost values, this paper focuses on the interdependencies between agglomeration, specialization and the strength of vertical linkages. A central concern is the idea of an 'industrial base,' which is attracting linked industries but is persistent to relocation. As a main finding, the intermediate cost share and substitution elasticity basically determine the strength of linkages. Thus, these parameters affect how strong the industrial base responds to changes in trade costs, relative wages and market size. The fourth paper 'The Spatial Dynamics of the European Biotech Industry' presents a simulation study of the R&D intensive biotech industry using the standard Venables model. Thus, it connects all three preceding papers and puts them into the real economic context of the European integration. The paper reviews the potential development of the European biotech industry with respect to its spatial structure. On the first stage, the present industrial situation as object of investigation is described and evaluated with respect to a further model implementation. In this context, the article introduces the findings of an online survey concerning international trade, conducted with German biotech firms in 2006. On the second stage, the results are completed by the outcomes of a numerical simulation within the New Economic Geography (NEG), considering vertical linkages between the biotech and pharmaceutical industries as an agglomerative force. The analysis reveals only a slight relocation tendency to the European periphery, constrained by market size, infrastructure and factor supply. In the final conclusions, central results of all four papers are summarized with respect to economic policy. Against the background of general legitimization and the impact of political intervention, Chapter 6 draws the main conclusions for location and innovation policies. In this regard, the industrial-base concept as well as the mobility of R&D play a central role during this discussion.
Expatriate success divided into two criteria, expatriate adjustment and expatriate job performance, is analyzed in relation to extraversion and its facets. Measurements of the Big Five and scales of adjustment as well as job performance were used by interviewing a sample of 80 German, Austrian and Swiss expatriates working in Costa Rica. The overall extraversion trait, gregariousness, assertiveness, and activity show meaningful effects on expatriate job performance. By analyzing expatriate adjustment and its relationship with extraversion and corresponding facets moderate effects were found between activity and interaction adjustment. Positive emotions with interaction adjustment as well as positive emotions with general adjustment show the largest effects. Furthermore, small effects were found for activity and warmth in respect to expatriate adjustment. Finally, suggestions for further research concerning extraversion in expatriate management are given.
Managing increasing environmental risks through agro-biodiversity and agri-environmental policies
(2008)
Agro-biodiversity can provide natural insurance to risk-averse farmers by reducing the variance of crop yield, and to society at large by reducing the uncertainty in the provision of public-good ecosystem services such as e.g. CO2 storage. We analyze the choice of agro-biodiversity by risk-averse farmers who have access to financial insurance, and study the implications for agri-environmental policy design when on-farm agro-biodiversity generates a positive risk externality. While increasing environmental risk leads private farmers to increase their level of on-farm agro-biodiversity, the level of agro-biodiversity in the laissez-faire equilibrium remains inefficiently low. We show how either one of two agri-environmental policy instruments can cure this risk-related market failure: an ex-ante Pigouvian subsidy on on-farm agro-biodiversity and an ex-post compensation payment for the actual provision of public environmental benefits. In the absence of regulation, welfare may increase rather than decrease with increasing environmental risk, if the agroecosystems is characterized by a high natural insurance function, low costs and large external benefits of agro-biodiversity.
The European Union’s Council Regulation on support for rural development by the European Agricultural Fund for Rural Development has introduced auctioning as a new instrument for granting agri-environmental payments and awarding conservation contracts for the recent multi-annual budgetary plan. This paper therefore deals with the conception and results of two case study auctions for conservation contracts. Results of two field experiments show much differentiated bid prices in the model-region and budgetary cost-effectiveness gains of up to 21% in the first auction and up to 36% in the repeated auction. Besides these promising results, some critical aspects as well as lessons to be learned will also be discussed in this paper to improve the design and performance of upcoming conservation auctions.
We develop a comprehensive multi-level approach to ecological economics (CML-approach) which integrates philosophical considerations on the foundations of ecological economics with an adequate operationalization. We argue that the subject matter and aims of ecological economics require a specific combination of inter- and transdisciplinary research, and discuss the epistemological position on which this approach is based. In accordance with this understanding of inter- and transdisciplinarity and the underlying epistemological position, we develop an operationalization which comprises simultaneous analysis on three levels of abstraction: concepts, models and case studies. We explain these levels in detail, and, in particular, deduce our way of generic modeling in this context. Finally, we illustrate the CML-approach and demonstrate its fruitfulness by the example of the sustainable management of semi-arid rangelands.
While it is a stylized fact that exporting firms pay higher wages than nonexporting firms, the direction of the link between exporting and wages is less clear. Using a rich set of German linked employer-employee panel data we follow over time plants that start to export. We show that the exporter wage premium does already exist in the years before firms start to export, and that it does not increase in the following years. Higher wages in exporting firms are thus due to self-selection of more productive, better paying firms into export markets; they are not caused by export activities.