Direct Vlasov simulations of electron-attracting cylindrical Langmuir probes in flowing plasmas

Current collection by positively polarized cylindrical Langmuir probes immersed in flowing plasmas is analyzed using a non-stationary direct Vlasov-Poisson code. A detailed description of plasma density spatial structure as a function of the probe-to-plasma relative velocity U is presented. Within the considered parametric domain, the well-known electron density maximum close to the probe is weakly affected by U. However, in the probe wake side, the electron density minimum becomes deeper as U increases and a rarified plasma region appears. Sheath radius is larger at the wake than at the front side. Electron and ion distribution functions show specific features that are the signature of probe motion. In particular, the ion distribution function at the probe front side exhibits a filament with positive radial velocity. It corresponds to a population of rammed ions that were reflected by the electric field close to the positively biased probe. Numerical simulations reveal that two populations of trapped electrons exist: one orbiting around the probe and the other with trajectories confined at the probe front side. The latter helps to neutralize the reflected ions, thus explaining a paradox in past probe theory.

Investigations on the distribution of air transport traffic and CO2 emissions within the European Union

This study analyses the structure of air traffic and its distribution among the different countries in the European Union, as well as traffic with an origin or destination in non-EU countries. Data sources are Eurostat statistics and actual flight information from EUROCONTROL. Relevant variables such as the number of flights, passengers or cargo tonnes and production indicators (RPKs) are used together with fuel consumption and CO2 emissions data. The segmentation of air traffic in terms of distance permits an assessment of air transport competition with surface transport modes. The results show a clear concentration of traffic in the five larger countries (France, Germany, Italy, Spain and UK), in terms of RPKs. In terms of distance the segment between 500 and 1000 km in the EU, has more flights, passengers, RTKs and CO2 emissions than larger distances. On the environmental side, the distribution of CO2 emissions within the EU Member States is presented, together with fuel efficiency parameters. In general, a direct relationship between RPKs and CO2 emissions is observed for all countries and all distance bands. Consideration is given to the uptake of alternative fuels. Segmenting CO2 emissions per distance band and aircraft type reveals which flights contribute the most the overall EU CO2 emissions. Finally, projections for future CO2 emissions are estimated, according to three different air traffic growth and biofuel introduction scenarios.

Assessment methodology applied to demand measures to change urban mobility behavior

In order to minimize car-based trips, transport planners have been particularly interested in understanding the factors that explain modal choices. Transport modelling literature has been increasingly aware that socioeconomic attributes and quantitative variables are not sufficient to characterize travelers and forecast their travel behavior. Recent studies have also recognized that users’ social interactions and land use patterns influence travel behavior, especially when changes to transport systems are introduced; but links between international and Spanish perspectives are rarely dealt with. The overall objective of the thesis is to develop a stepped methodology that integrate diverse perspectives to evaluate the willingness to change patterns of urban mobility in Madrid, based on four steps: (1st) analysis of causal relationships between both objective and subjective personal variables, and travel behavior to capture pro-car and pro-public transport intentions; (2nd) exploring the potential influence of individual trip characteristics and social influence variables on transport mode choice; (3rd) identifying built environment dimensions on travel behavior; and (4th) exploring the potential influence on transport mode choice of extrinsic characteristics of individual trip using panel data, land use variables using spatial characteristics and social influence variables. The data used for this thesis have been collected from a two panel smartphone-based survey (n=255 and 190 respondents, respectively) carried out in Madrid. Although the steps above are mainly methodological, the application to the area of Madrid allows deriving important results that can be directly used to forecast travel demand and to evaluate the benefits of specific policies that might be implemented in the area. The results demonstrated, respectively: (1st) transport policy actions are more likely to be effective when pro-car intention has been disrupted first; (2nd) the consideration of “helped” and “voluntary” users as tested here could have a positive and negative impact, respectively, on the use of public transport; (3rd) the importance of density, design, diversity and accessibility underlying dimensions responsible for land use variables; and (4th) there are clearly different types of combinations of social interactions, land use and time frame on travel behavior studies. Finally, with the objective to study the impact of demand measures to change urban mobility behavior, those previous results have been considered in a unique way, a hybrid discrete choice model has been used on a 5th step. Then it can be concluded that urban mobility behavior is not only ruled by the maximum utility criterion, but also by a strong psychological-environment concept, developed without the mediation of cognitive processes during choice, i.e., many people using public transport on their way to work do not do it for utilitarian reasons, but because no other choice is available. Regarding built environment dimensions, the more diversity place of residence, the more difficult the use of public transport or walking.

Impacto del entorno institucional en la financiación público-privada de infraestructuras de transporte

Actualmente el sector privado posee un papel relevante en la provisión y gestión de infraestructuras de transporte en los países de ingreso medio‐bajo, principalmente a través de los proyectos de participación público‐privada (PPPs). Muchos países han impulsado este tipo de proyectos con el fin de hacer frente a la gran demanda de infraestructuras de transporte existente, debido a la escasez de recursos públicos y a la falta de eficiencia en la provisión de los servicios públicos. Como resultado, las PPPs han experimentado un crecimiento importante en las últimas dos décadas a nivel mundial. A pesar de esta tendencia creciente, muchos países no han sido capaces de atraer la participación del sector privado para la provisión de sus infraestructuras o no han logrado el nivel de participación privada que habrían requerido para alcanzar sus objetivos. Según numerosos autores, el desarrollo y el éxito de los proyectos PPP de infraestructuras de transporte de cualquier país está condicionado por una diversidad de factores, siendo uno de ellos la calidad de su entorno institucional. La presente tesis tiene como objetivo principal analizar la influencia del entorno institucional en el volumen de inversión en proyectos de participación público‐privada de infraestructuras de transporte en los países de ingreso medio‐bajo. Para acometer dicho objetivo se ha realizado un análisis empírico de 81 países distribuidos en seis regiones del mundo, durante el periodo 1996‐2013. En el análisis se han desarrollado dos modelos empíricos aplicando principalmente dos metodologías: el contraste de hipótesis y los modelos de datos de panel Tobit. El desarrollo de estos modelos ha permitido analizar de una forma exhaustiva el tema de estudio. Los resultados obtenidos aportan evidencia de que la calidad del entorno institucional posee una influencia significativa en el volumen de inversión en los proyectos PPP de transporte. En general, en esta tesis se muestran evidencias empíricas de que el sector privado ha tendido a invertir en mayor medida en países con entornos institucionales fuertes, es decir, en aquellos países en los que ha existido un mayor nivel de Estado de derecho, estabilidad política y regulatoria, efectividad del gobierno, así como un mayor control de la corrupción. Además, aquellos países donde se ha registrado una mejora en el nivel de su calidad institucional también han experimentado un incremento en el volumen de inversión en PPP de transporte. The private sector has an important role in the provision and management of transport infrastructure in countries of medium‐low income, primarily through projects of public‐private partnerships (PPPs). Many countries have developed PPP projects to meet the high demand of transport infrastructure, due to the scarcity of public resources and the lack of efficiency in the provision of public services. As a result, PPPs have experienced a significant growth, worldwide, in the past two decades. Despite this growing trend, many countries have not been able to attract private sector participation in the provision of infrastructure or have not accomplished the level of private participation that would have required to achieve its objectives. According to various authors, the development of PPP projects for transport infrastructure is determined by a number of factors, one of them being the quality of the institutional environment. The main objective of this dissertation is to analyze the influence of the institutional environment on the volume of investment, in projects of public‐private partnerships for transport infrastructure in countries of medium‐low income. In order to meet this objective, we conducted an empirical analysis of 81 countries, in six regions of the world, during the period of 1996‐2013. The analysis used two empirical models, implementing different methodologies and various statistical techniques: hypothesis testing, and Tobit model using panel data. The development of these models allowed to carry out a more comprehensive analysis. The results show that the quality of the institutional environment has a significant influence on the volume of investment in PPP projects of transport. Overall, this dissertation shows that the private sector tends to invest more in countries with stronger institutional environments, i.e. countries where there has been a higher level of Rule of Law, political and regulatory stability, and an effective control of corruption. In addition, those that have improved the level of institutional quality have also experienced an increase in the volume of investment in PPP of transport.

The role of private sector in development: The relation between public-private investment in infrastructure and agricultural exports in developing countries

Increasing foreign private investment in developing countries explains why the Public-Private Investment (PPI) is becoming a key tool to reach the development goal. This article analyzes the relation between PPI in infrastructure and agricultural exports in developing countries. We use the panel data approach (52 countries and 17 years). Results show that PPI in infrastructure has a positive impact on agricultural exports of developing countries. The impact is greater in developing countries with higher income rates. This suggests that the lower income countries require the intervention of public sector without which private investment cannot help to economic development.

Sustentabilidade Empresarial: Um Estudo Comparativo Sobre o Desempenho e Valor Financeiro de Empresas Listadas no Mercado Acionário Brasileiro

Com o crescente aumento da cultura de proteção ambiental, o tema sustentabilidade vem ganhando cada vez mais espaço na vida das pessoas e principalmente na rotina das organizações. Existem algumas correntes teóricas propondo que para existir uma perenidade das organizações, estas devem incorporar em seu plano estratégico, todos os elementos que permitam um equilíbrio nas relações com os stakeholders. Já outras linhas teóricas, defendem que as empresas devem focar todos seus esforços para atender os acionistas (shareholders), maximizando os lucros e agregando valor. Neste contexto, alguns índices de sustentabilidade foram surgindo mundo afora, visando combinar com a já presente visão de resultados financeiros das organizações, também o alcance do bem estar para a sociedade e proteção do meio ambiente. No Brasil, em Novembro de 2005, foi lançando o ISE Índice de Sustentabilidade Empresarial, que foi desenvolvido para uma gama de empresas que apresentam boas práticas de sustentabilidade. Surge, então, o questionamento se a adoção das práticas de sustentabilidade pode de alguma forma, proporcionar melhor desempenho financeiro para as organizações que as adotam, pois de acordo com a teoria dos stakeholders, as instituições que conseguem atender as necessidades das partes interessadas têm seu valor maximizado ao longo do tempo. Com relação a isto, este presente estudo procura averiguar se as empresas que estão listadas no ISE, excluindo as empresas do setor de materiais básicos, utilidade pública, e financeiro, do período de 2006 a 2008, desenvolveram desempenho financeiro superior às outras empresas que não fazem parte do índice no mesmo período. Foram selecionados dados secundários, utilizando a base de dados da Economática, criando dois grupos para comparação, onde um grupo consta de empresas que estão exclusivamente listadas no ISE, consideradas sustentáveis e outro grupo de empresas, formado por empresas listadas no IBOVESPA e que não participaram do ISE. Tomando o Q de Tobin como a variável dependente e índices de Tamanho da Empresa, Distribuição de Dividendos, Debt to Equity, ROA, Crescimento de Vendas, Crescimento dos Investimentos, Diversificação de Mercado, Endividamento como variáveis independentes, foram aplicados testes estatísticos comparando as médias dos índices, seguido do teste t de student, e regressões de dados em painel pooled, fixed e random effects para encontrar a possível correlação entre sustentabilidade e valor da empresa. Os resultados encontrados apontam uma relação entre sustentabilidade empresarial e desempenho financeiro.(AU)

Sustentabilidade Empresarial: Um Estudo Comparativo Sobre o Desempenho e Valor Financeiro de Empresas Listadas no Mercado Acionário Brasileiro

Com o crescente aumento da cultura de proteção ambiental, o tema sustentabilidade vem ganhando cada vez mais espaço na vida das pessoas e principalmente na rotina das organizações. Existem algumas correntes teóricas propondo que para existir uma perenidade das organizações, estas devem incorporar em seu plano estratégico, todos os elementos que permitam um equilíbrio nas relações com os stakeholders. Já outras linhas teóricas, defendem que as empresas devem focar todos seus esforços para atender os acionistas (shareholders), maximizando os lucros e agregando valor. Neste contexto, alguns índices de sustentabilidade foram surgindo mundo afora, visando combinar com a já presente visão de resultados financeiros das organizações, também o alcance do bem estar para a sociedade e proteção do meio ambiente. No Brasil, em Novembro de 2005, foi lançando o ISE Índice de Sustentabilidade Empresarial, que foi desenvolvido para uma gama de empresas que apresentam boas práticas de sustentabilidade. Surge, então, o questionamento se a adoção das práticas de sustentabilidade pode de alguma forma, proporcionar melhor desempenho financeiro para as organizações que as adotam, pois de acordo com a teoria dos stakeholders, as instituições que conseguem atender as necessidades das partes interessadas têm seu valor maximizado ao longo do tempo. Com relação a isto, este presente estudo procura averiguar se as empresas que estão listadas no ISE, excluindo as empresas do setor de materiais básicos, utilidade pública, e financeiro, do período de 2006 a 2008, desenvolveram desempenho financeiro superior às outras empresas que não fazem parte do índice no mesmo período. Foram selecionados dados secundários, utilizando a base de dados da Economática, criando dois grupos para comparação, onde um grupo consta de empresas que estão exclusivamente listadas no ISE, consideradas sustentáveis e outro grupo de empresas, formado por empresas listadas no IBOVESPA e que não participaram do ISE. Tomando o Q de Tobin como a variável dependente e índices de Tamanho da Empresa, Distribuição de Dividendos, Debt to Equity, ROA, Crescimento de Vendas, Crescimento dos Investimentos, Diversificação de Mercado, Endividamento como variáveis independentes, foram aplicados testes estatísticos comparando as médias dos índices, seguido do teste t de student, e regressões de dados em painel pooled, fixed e random effects para encontrar a possível correlação entre sustentabilidade e valor da empresa. Os resultados encontrados apontam uma relação entre sustentabilidade empresarial e desempenho financeiro.(AU)

Identifying the role of natural resources in knowledge-based strategies of development

Knowledge has adopted a preferential role in the explanation of development while the evidence about the effect of natural resources in countries’ performance is more controversial in the economic literature. This paper tries to demonstrate that natural resources may positively affect growth in countries with a strong natural resources specialization pattern although the magnitude of these effects depend on the type of resources and on other aspects related to the production and innovation systems. The positive trajectory described by a set of national economies mainly specialized in natural resources and low-tech industries invites us to analyze what is the combination of factors that serves as engine for a sustainable development process. With panel data for the period 1996-2008 we estimate an applied growth model where both traditional factors and other more related to innovation and absorptive capabilities are taken into account. Our empirical findings show that according to the postulates of a knowledge-based approach, a framework that combines physical and intangible factors is more suitable for the definition of development strategies in those prosperous economies dominated by natural resources and connected activities, while the internationalization process of activities and technologies become also a very relevant aspect.

Technical efficiency in the retail food industry: the influence of inventory investment, wage levels, and age of the firm

The objective of this paper is to estimate technical efficiency in retailing; and the influence of inventory investment, wage levels, and firm age on this efficiency. We use the output supermarket chains’ sales volume, calculated isolating the retailer price effect on its sales revenue. This output allows us to estimate a strictly technical concept of efficiency. The methodology is based on the estimation of a stochastic parametric function. The empirical analyses applied to panel data on a sample of 42 supermarket chains between 2000 and 2002 show that inventory investment and wage level have an impact on technical efficiency. In comparison, the effect of these factors on efficiency calculated through a monetary output (sales revenue) shows some differences that could be due to aspects related to product prices.

Nonlinear dynamics in discretionary accruals: An analysis of bank loan-loss provisions

Several studies have analyzed discretionary accruals to address earnings-smoothing behaviors in the banking industry. We argue that the characteristic link between accruals and earnings may be nonlinear, since both the incentives to manipulate income and the practical way to do so depend partially on the relative size of earnings. Given a sample of 15,268 US banks over the period 1996–2011, the main results in this paper suggest that, depending on the size of earnings, bank managers tend to engage in earnings-decreasing strategies when earnings are negative (“big-bath”), use earnings-increasing strategies when earnings are positive, and use provisions as a smoothing device when earnings are positive and substantial (“cookie-jar” accounting). This evidence, which cannot be explained by the earnings-smoothing hypothesis, is consistent with the compensation theory. Neglecting nonlinear patterns in the econometric modeling of these accruals may lead to misleading conclusions regarding the characteristic strategies used in earnings management.

Investment behaviour of EU arable crop farms in selected EU countries and the impact of policy reforms. Factor Markets Working Document No. 42, May 2013

This deliverable provides a comparative analysis, among selected EU member states, of the investment demand of a sample of specialised field crop farms for farm buildings, machinery and equipment as determined by different types and levels of Common Agricultural Policy support. It allows for the existence of uncertainty in the price of output farmers receive and for both long- and short-run determinants of investment levels, as well as for the presence of irregularities in the cost adjustment function due to the existence of threshold-type behaviours. The empirical estimation reveals that three investment regimes are consistently identified in Germany and Hungary, across asset and support types, and in France for machinery and equipment. More traditional disinvestment-investment type behaviours characterise investment in farm building in France and the UK, across support types, and Italy for both asset classes under coupled payments. The long-run dynamic adjustment of capital stocks is consistently and significantly estimated to be towards a – mostly non-stationary – lower level of capitalisation of the farm analysed. By contrast, the expected largely positive short-run effects of an increase in output prices are often not significant. The effect of CAP support on both types of investment is positive, although seldom significant, while the proxy for uncertainty employed fails to be significant yet, in most cases, has the expected effect of reducing the investment levels.

Continuous Off-the-Job Training in East Germany After Unification: Preliminary Results of an Evaluation of the Effects for Individual Workers, CES Germany & Europe Working Papers, No. 05.9, 19 July, 1995

Retraining the labor force to match the demands of a modem economy is seen as an important task during the transition process from a centrally-planned to a market economy. This need was particularly pressing in East Germany, because the transition process has proceeded much faster than in the rest of Eastern Europe. Therefore, substantial resources have been devoted to this purpose. This paper analyzes the impact of continuous off-the-job training in East Germany from the point of view of individuals who were part of the labor force before German unification in 1990. It tries to answer questions about the average gains from participating in a specific type of training. Typical outcomes considered to measure those gains are income, employment status, job security, and expected future changes in job position. The methodology used for the evaluation is the potential outcome approach to causality. This approach has received considerable attention in the statistical literature over the last fifteen years and it has recently been rediscovered by the econometric literature as well. It is adapted to allow for important permanent and transitory shocks, such as unemployment, which influence the decision to participate in the training as well as future labor market outcomes. The empirical part is based on the first four waves of the Socio-Economic Panel (GSOEP)-East (1990-1993). This panel data set has the advantage that the fourth wave contains a special survey on continuous training and that it allows keeping track of individual behavior on a monthly, respectively yearly, basis. The econometric analysis focuses on off-the-job training courses that began after unification and were completed not later than in early 1993. Although it is obviously too early to evaluate the long-term implications, the results suggest that there are no positive effects in the short run.

Institutions and Structural Unemployment: Do Capital-Market Imperfections Matter? CES Germany & Europe Working Papers, No. 00.8, December 2000

This paper analyzes whether differences in institutional structures on capital markets contribute to explaining why some DECO-countries, in particular the Anglo-Saxon countries, have been much more successful over the last two decades in producing employment growth and in reducing unem­ployment than most continental-European DECO-countries. It is argued that the often-blamed labor market rigidities alone, while important, do not provide a satisfactory explanation for these differ­ences across countries and over time. Financial constraints are potentially important obstacles against creating new firms and jobs and thus against coping well with structural change and against moving successfully toward the "new economy". Highly developed venture capital markets should help to alleviate such financial constraints. This view that labor-market institutions should be sup­plemented by capital market imperfections for explaining differences in employment performances is supported by our panel data analysis, in which venture capital turns out to be a significant insti­tutional variable.

Sustainability, Resource Efficiency and Competitiveness. An Assessment of Resource Efficiency Policies in the European Union. Bruges European Economic Research Papers (BEER) 32/2015.

Addressing high and volatile natural resource prices, uncertain supply prospects, reindustrialization attempts and environmental damages related to resource use, resource efficiency has evolved into a highly debated proposal among academia, policy makers, firms and international financial institutions (IFIs). In 2011, the European Union (EU) declared resource efficiency as one of its seven flagship initiatives in its Europe 2020 strategy. This paper contributes to the discussions by assessing its key initiative, the Roadmap to a Resource Efficient Europe (EC 2011 571), following two streams of evaluation. In a first step, resource efficiency is linked to two theoretical frameworks regarding sustainability, (i) the sustainability triangle (consisting of economic, social and ecological dimensions) and (ii) balanced sustainability (combining weak and strong sustainability). Subsequently, both sustainability frameworks are used to assess to which degree the Roadmap follows the concept of sustainability. It can be concluded that it partially respects the sustainability triangle as well as balanced sustainability, primarily lacking a social dimension. In a second step, following Steger and Bleischwitz (2009), the impact of resource efficiency on competitiveness as advocated in the Roadmap is empirically evaluated. Using an Arellano–Bond dynamic panel data model reveals no robust impact of resource efficiency on competiveness in the EU between 2004 and 2009 – a puzzling result. Further empirical research and enhanced data availability are needed to better understand the impacts of resource efficiency on competitiveness on the macroeconomic, microeconomic and industry level. In that regard, strengthening the methodologies of resource indicators seem essential. Last but certainly not least, political will is required to achieve the transition of the EU-economy into a resource efficient future.

State Aid to Infrastructure: Do Competitively Selected Operators Obtain an Undue Advantage? Bruges European Economic Research Papers (BEER) 33/2015

Addressing high and volatile natural resource prices, uncertain supply prospects, reindustrialization attempts and environmental damages related to resource use, resource efficiency has evolved into a highly debated proposal among academia, policy makers, firms and international financial institutions (IFIs). In 2011, the European Union (EU) declared resource efficiency as one of its seven flagship initiatives in its Europe 2020 strategy. This paper contributes to the discussions by assessing its key initiative, the Roadmap to a Resource Efficient Europe (EC 2011 571), following two streams of evaluation. In a first step, resource efficiency is linked to two theoretical frameworks regarding sustainability, (i) the sustainability triangle (consisting of economic, social and ecological dimensions) and (ii) balanced sustainability (combining weak and strong sustainability). Subsequently, both sustainability frameworks are used to assess to which degree the Roadmap follows the concept of sustainability. It can be concluded that it partially respects the sustainability triangle as well as balanced sustainability, primarily lacking a social dimension. In a second step, following Steger and Bleischwitz (2009), the impact of resource efficiency on competitiveness as advocated in the Roadmap is empirically evaluated. Using an Arellano–Bond dynamic panel data model reveals no robust impact of resource efficiency on competiveness in the EU between 2004 and 2009 – a puzzling result. Further empirical research and enhanced data availability are needed to better understand the impacts of resource efficiency on competitiveness on the macroeconomic, microeconomic and industry level. In that regard, strengthening the methodologies of resource indicators seem essential. Last but certainly not least, political will is required to achieve the transition of the EU-economy into a resource efficient future.