Is the Brazilian stockmarket efficient?

Employing both cointegration analysis and a variety of Granger causality tests, we examine whether the Brazilian stockmarket is efficient in processing new information about public macroeconomic data (semi-strong efficiency). We find the stockmarket to be inefficient, which is in line with most results for other emerging markets.

Informational inefficiency of the Brazilian stockmarket

Employing both cointegration analysis and a variety of Granger causality tests, we examine whether the Brazilian stockmarket is efficient in processing new information about public macroeconomic data (semi-strong efficiency). We find the stockmarket to be inefficient, which is in line with most results for other emerging markets.stockmarket semi-strong informational efficiency; cointegration; Granger causality; macroeconomic variables; Brazilian economy

Slowly Rotating Anisotropic Neutron Stars in General Relativity and Scalar-Tensor Theory

Some models (such as the Skyrme model, a low-energy effective field theory for QCD) suggest that the high-density matter prevailing in neutron star interiors may be significantly anisotropic. Anisotropy is known to affect the bulk properties of nonrotating neutron stars in General Relativity. In this paper we study the effects of anisotropy on slowly rotating stars in General Relativity. We also consider one of the most popular extensions of Einstein's theory, namely scalar-tensor theories allowing for spontaneous scalarization (a phase transition similar to spontaneous magnetization in ferromagnetic materials). Anisotropy affects the moment of inertia of neutron stars (a quantity that could potentially be measured in binary pulsar systems) in both theories. We find that the effects of scalarization increase (decrease) when the tangential pressure is bigger (smaller) than the radial pressure, and we present a simple criterion to determine the onset of scalarization by linearizing the scalar-field equation. Our calculations suggest that binary pulsar observations may constrain the degree of anisotropy or even, more optimistically, provide evidence for anisotropy in neutron star cores.Comment: 19 pages, 7 figures, 1 table. Matches version in press in CQG. Fixed small typo

Top-tier advisors in M&A transactions : they used to matter

This master thesis investigates the effect of top-tier advisors on bidder returns, probability of completion and time to completion of M&A deals announced between January 1995 and December 2015. In this context, the fees received by top-tier advisors and their ability to identify and appropriate synergies are also subjected to study. Based on a sample of 6716 U.S. and cross border deals, we found that (1) after 2001 top-tier advisors are no longer associated with higher cumulative abnormal returns; (2) toptier advisors are neither significantly associated with higher probability of completion nor with shorter time to completion in acquisition of public targets; (3) top-tier advisors can indeed identify deals with larger synergies, butthey fail to appropriate them to the bidder firm; (4) top-tier advisors received higher fees on U.S. deals than non-top-tier advisors would have demanded for the same deals; (5) when considering the largest deals (Mega Deals), after 2001 it is found no support for the top-tier advisors superiority neither in U.S. nor in cross border deals.Esta tese investiga o efeito de consultores top em fusoes e aquisiçoes anunciadas entre janeiro de 1995 e dezembro de 2015. Neste ambito e estudado o retorno da empresa adquirente, a probabilidade de conclusao da transaçao, o tempo para a conclusao da transaçao, a capacidade de o consultor identificar sinergias e de as apropriar para a empresa licitante. Finalmente, e estudado o papel dos consultores top no caso especffico das grandes transaçoes. Com base numa amostra de 6716 transaçoes de alvos americanos e nao americanos, chegou-se a conclusoes de que (1) ap6s 2001 os consultores top nao estao associados a retornos acumulados superiores a consultores nao top (2) consultores top nao estao significativamente associados a uma maior probabilidade de conclusao da transaçao, assim como nao estao associados a um menor tempo para a concretizaçao de transaçoes no que se refere a alvos publicos (3) consultores top sao capazes de identificar negócios com maiores sinergias, no entanto, nao sao capazes de as apropriar para a empresa licitante (4) consultores top receberam maiores comissoes do que aquelas que seriam cobradas por consultores nao top nas mesmas transaçoes (5) no que se refere as grandes transaçoes, após 2001 nao sao encontradas evidencias da superioridade dos consultores top quer em alvos americanos, quer em alvos nao americanos

Dificuldades brasileiras no setor de Energia elétrica nos anos de 2014 e 2015: Uma perspectiva da população de Guarus em Campos dos Goytacazes RJ

O setor de energia elétrica brasileiro passou por grande dificuldade na geração nos anos de 2014 e 2015. Com uma matriz energética em que a maior fonte de energia é a hidráulica, o país sentiu o reflexo da seca, a qual ocasionou uma baixa no volume de água nos reservatórios das usinas hidrelétricas. Com a utilização de outras fontes de energia, o custo de geração elevou-se, provocando um aumento nas contas de energia da população.  Este artigo apresenta os resultados de uma pesquisa feita por meio da aplicação de um questionário de abordagem quantitativa, estruturado e objetivo descritivo, de como ocorreu o consumo de energia nas residências dos moradores da região do distrito de Guarus na cidade de Campos dos Goytacazes/RJ durante o período mais intenso de crise. Além disso, foi observado as medidas utilizadas por esta população a fim de reduzir o consumo de energia elétrica em suas residências. Quanto aos motivos que levaram à alta da conta de energia elétrica, 28% dos entrevistados atribuíram isso à corrupção no governo, enquanto 31% não souberam dizer os motivos. Além disso, há ainda uma porcentagem de 9% dos entrevistados que desconhecem a existência do aumento. Os dados mostram também que, em média, 10% da renda familiar é destinada ao pagamento da tarifa de eletricidade. A maioria dos entrevistados, cerca de 80%, afirmou estar adotando medidas como manter as luzes e equipamentos desligados quando não havia pessoas no ambiente. Os resultados mostram que as pessoas buscam formas de economizar energia e não estavam satisfeitas com o aumento das tarifas, no entanto, mostra que a população não tem um olhar crítico quanto ao motivo que levou a crise no setor elétrico se sobressaindo a corrupção na política brasileira

Interacting Microsoft Visual Basic Procedures (Macros) and GIS tools in order to access optimal location and maximum use of railways and railway infrastructures

Some parts of the Portuguese railway infrastructure have been neglected through time: Rural lines have been abandoned, investment in new infrastructure is sometimes delayed, and marketing strategies to keep or attract more users have not been pursued. Simultaneously, problems with urban congestion, pollution and mobility for the young, the elderly, the poor, and the handicapped are putting forward the discussion about new or more sustainable modes of transportation. Common sense of public officials, other lobbying groups, and the locals demand new, trendy train lines. And while some axes may have the potential to justify rail lines, others seem to lack population or funding to be enabled. One major problem in order to evaluate the worthiness of these rail projects has been the fact that very often the studies of travel demand and physical implantation are done separately. Travel demand analysis is done based on the four-step model (trip generation, distribution, modal split, and network assignment) using survey data and the network system, using a relatively wide zoning. The importance of interacting with other, finer, information (i.e. slope, density of population, environmental sensitivity, or other socio-economic and land use information) with the development of the travel analysis demand will enhance the analysis/results and increase the chance of proposing lines that are both optimal in location and will have the maximum use by the citizens. Off the shelf software is still unable to perform this kind of operations. Some perform the analysis using existing networks, and no information on the land is available besides the zoning system, other software propose lines accordingly to land slopes, but no trip information is included. GIS packages have the capacity to include the land information and some have some transportation analysis, but are lacking computation capabilities and algorithms to perform analysis similar to off-the-shelf transportation software. In order to develop this kind of integrated analysis it is important to have a good knowledge of the algorithms and analysis required by transportation and of the tools/opportunities offered by the GIS packages. This paper presents a methodology that integrates the transportation algorithms with the GIS functionalities, using excel macro-language. The result is an interaction of both travel demand analysis and site selection. The characteristics of the place constrain the travel demand analysis, but on its own the travel demand analysis define not only the buffer of the train line, but systematically enhance the shape of the line and the location of the stops each time the results of a phase of the travel demand analysis is outputted. This paper offers guidelines for those developing travel demand analysis including some site selection criteria, and it can be a starting point for those of whom intend to develop further application of in the GIS fields.