Market trends and dilemmas of parenthal participation in schools

Este artigo descreve e analisa o impacto da definição e implementação de um novo modelo de gestão dos estabelecimentos de ensino não superior (Dec-lei nº115_A/98) nos padrões de cidadania e equidade do ensino público Português. A institucionalização deste modelo representa uma mudança na matriz centralista e burocrática do referido ensino público e sugere uma aproximação às concepções neo-gerencialistas e neo-liberais que, desde meados dos anos 80, têm dominado a agenda política de muitos países desenvolvidos e de alguns organismos internacionais. Os resultados da pesquisa sugerem que a implementação do novo modelo de gestão contribuiu para reforçar os padrões de diferenciação social no ensino básico (1ºciclo) e, mais especificamente, para preservar as .vantagens competitivas. da classe média na escola pública Portuguesa.

What drives corporate default risk premia? Evidence from the CDS market

This paper studies the evolution of the default risk premia for European firms during the years surrounding the recent credit crisis. We employ the information embedded in Credit Default Swaps (CDS) and Moody’s KMV EDF default probabilities to analyze the common factors driving this risk premia. The risk premium is characterized in several directions: Firstly, we perform a panel data analysis to capture the relationship between CDS spreads and actual default probabilities. Secondly, we employ the intensity framework of Jarrow et al. (2005) in order to measure the theoretical effect of risk premium on expected bond returns. Thirdly, we carry out a dynamic panel data to identify the macroeconomic sources of risk premium. Finally, a vector autoregressive model analyzes which proportion of the co-movement is attributable to financial or macro variables. Our estimations report coefficients for risk premium substantially higher than previously referred for US firms and a time varying behavior. A dominant factor explains around 60% of the common movements in risk premia. Additionally, empirical evidence suggests a public-to-private risk transfer between the sovereign CDS spreads and corporate risk premia.

Extreme Value Theory versus traditional GARCH approaches applied to financial data: a comparative evaluation

Although stock prices fluctuate, the variations are relatively small and are frequently assumed to be normal distributed on a large time scale. But sometimes these fluctuations can become determinant, especially when unforeseen large drops in asset prices are observed that could result in huge losses or even in market crashes. The evidence shows that these events happen far more often than would be expected under the generalized assumption of normal distributed financial returns. Thus it is crucial to properly model the distribution tails so as to be able to predict the frequency and magnitude of extreme stock price returns. In this paper we follow the approach suggested by McNeil and Frey (2000) and combine the GARCH-type models with the Extreme Value Theory (EVT) to estimate the tails of three financial index returns DJI,FTSE 100 and NIKKEI 225 representing three important financial areas in the world. Our results indicate that EVT-based conditional quantile estimates are much more accurate than those from conventional AR-GARCH models assuming normal or Student’s t-distribution innovations when doing out-of-sample estimation (within the insample estimation, this is so for the right tail of the distribution of returns).

The impact of family control on firm's return

Family firm is a field of growing interest. The aim of this article is to understand whether CEOs identity impacts family firm’s stock returns. From a sample of Portuguese and Spanish family firms findings show that who manages the firms result in significantly different risk exposure. Moreover, we find that the abnormal return found by Fahlenbrach (2009) to founder-controlled firms disappear when we use valueweighted portfolios and include two new factors: market aggregate illiquidity and debt intensity to the four-factor Carhart model. Finally, our results explain why the majority of family firm is controlled by its founder.

Compensação de executivos: stock options: o caso particular da compensação dos altos executivos

Orientadora: Mestre Cláudia Maria Ferreira Pereira Lopes

The Interpretation of Verbal Probability Expressions Used in the IAS/IFRS: the auditors Rrgistered with the portuguese securities market commission

One of the main arguments in favour of the adoption and convergence with the international accounting standards published by the IASB (i.e. IAS/IFRS) is that these will allow comparability of financial reporting across countries. However, because these standards use verbal probability expressions (v.g. “probable”) when establishing the recognition and disclosure criteria for accounting elements, they require professional accountants to interpret and classify the probability of an outcome or event taking into account those terms and expressions and to best decide in terms of financial reporting. This paper reports part of a research we carried out on the interpretation of “in context” verbal probability expressions used in the IAS/IFRS by the auditors registered with the Portuguese Securities Market Commission, the Comissão do Mercado de Valores Mobiliários (CMVM). Our results provide support for the hypothesis that culture affects the CMVM registered auditors’ interpretation of verbal probability expressions through its influence on the accounting value (or attitude) of conservatism. Our results also suggest that there are significant differences in their interpretation of the term “probable”, which is consistent with literature in general. Since “probable” is the most frequent verbal probability expression used in the IAS/IFRS, this may have a negative impact on financial statements comparability.

La social stock exchange au Portugal: un nouvel allié de l'économie sociale

Résumé Cet article vise à contribuer à la connaissance de la Bolsa de Valores Sociais (BVS) — Social Stock Exchange — récemment créé au Portugal, dont le but primatial était de permettre la prise de moyens de financement des entités de l'Économie Sociale engagées dans des projets d'éducation et d'entreprenariat. Il se penchera sur la qualification juridique des divers types d'entités cotées dans la BVS, sur le concept d'investisseur social et sur la protection dont il jouira, vis-à-vis des exigences de transparence et de gouvernance qui incombent à ces entités. Le thème proposé sera examiné en soulignant les virtualités et le potentiel de la BVS, faisant référence à l'un ou à l'autre sujet qui viennent à effet, avec un accent particulier sur l'avantage d'élaborer un code de gouvernance corporative pour les entités de l'Économie Sociale. Abstract This article aims to contribute to the knowledge of the Bolsa de Valores Sociais (BVS) — Social Stock Exchange — recently created in Portugal, whose primatial purpose was to allow the taking of means of financing the Social Economy entities, engaged in projects in education and entrepreneurship. It will reflect on the legal classification of the various types of entities rated in the BVS, on the concept of social investor and on the protection he will enjoy, leading to the consequent demands for transparency and governance that falls upon those entities. The proposed theme will be discussed highlighting the virtues and potential of BVS, playing in one or two topics that comes to purpose, with particular emphasis on the relevance of drawing up a code of corporate governance for entities of the Social Economy. Resumen Este artículo tiene como objetivo contribuir al conocimiento de la Bolsa de Valores Sociales (BVS), recientemente creada en Portugal, cuya finalidad principal es que las entidades de la economía social dedicadas a proyectos en las áreas de educación y de iniciativa empresarial puedan obtener medios financieros. Se abordará la calificación jurídica de los diversos tipos de entidades que cotizan en la BVS, así como el concepto de inversor social y la protección de que éste goza, con las consiguientes exigencias en materia de transparencia y de gobierno que recaen sobre esas entidades. Se analizará la temática propuesta destacando las virtudes y potencialidades de la BVS, sin omitir algún otro tópico adyacente que resulte relevante, en especial la conveniencia de que sea elaborado un código de gobernanza corporativa para las entidades de la economía social.

Short-term electricity prices forecasting in a competitive market by a hybrid PSO-ANFIS approach

In this paper, a novel hybrid approach is proposed for electricity prices forecasting in a competitive market, considering a time horizon of 1 week. The proposed approach is based on the combination of particle swarm optimization and adaptive-network based fuzzy inference system. Results from a case study based on the electricity market of mainland Spain are presented. A thorough comparison is carried out, taking into account the results of previous publications, to demonstrate its effectiveness regarding forecasting accuracy and computation time. Finally, conclusions are duly drawn. (C) 2012 Elsevier Ltd. All rights reserved.

Da programação de fluxo à televisão de stock: programação e serviço público

No futuro, o papel da televisão pública ver-se-á condicionado pelo processo acelerado de evolução que marca uma transição da forma dominante da televisão de fluxo à televisão de stock – algo que já acontece, aliás, nos nossos dias. O meio tem evoluído desde o seu nascimento, respondendo a uma tensão existente entre dois vectores de força, em cujos pólos encontramos, por um lado, a inovação tecnológica e, por outro, a regulação. O primeiro pólo está representado na linha temporal pelo movimento entre o deslumbramento da tecnologia analógica e o da tecnologia digital. O segundo marca o momento em que a televisão deixa de ser considerada um bem público (ideia dominante) e passa a ser vista como mais uma indústria. Os dois pólos têm mantido uma relação activa e de mútuo condicionamento. Pode-se dizer que a regra subjacente a esta dinâmica tem sido a seguinte: a um menor grau de inovação tecnológica corresponde uma maior regulação; um maior grau de inovação está associado a uma maior desregulação. Se concordamos que o nascimento da televisão corresponde ao grau zero de inovação (pese embora a própria invenção da mesma tenha constituído uma novidade espectacular), também é verdade que esse grau pressupunha o uso de uma tecnologia que possibilitava a transmissão à distância de som e imagens em movimento, sem necessidade de se dispor de um elo físico. Para tal, nesta fase de desenvolvimento tecnológico, era utilizada a modulação das ondas hertzianas, um bem escasso que permitia transmitir sem interferências um número limitado de canais.

A risk-averse optimization model for trading wind energy in a market environment under uncertainty

In this paper, a stochastic programming approach is proposed for trading wind energy in a market environment under uncertainty. Uncertainty in the energy market prices is the main cause of high volatility of profits achieved by power producers. The volatile and intermittent nature of wind energy represents another source of uncertainty. Hence, each uncertain parameter is modeled by scenarios, where each scenario represents a plausible realization of the uncertain parameters with an associated occurrence probability. Also, an appropriate risk measurement is considered. The proposed approach is applied on a realistic case study, based on a wind farm in Portugal. Finally, conclusions are duly drawn. (C) 2011 Elsevier Ltd. All rights reserved.

A importância dos fluxos de caixa na análise da solvência, liquidez e visibilidade das empresas

Orientada por: Prof. Doutora Cláudia Lopes

Short-term electricity prices forecasting in a competitive market by a hybrid intelligent approach

In this paper, a hybrid intelligent approach is proposed for short-term electricity prices forecasting in a competitive market. The proposed approach is based on the wavelet transform and a hybrid of neural networks and fuzzy logic. Results from a case study based on the electricity market of mainland Spain are presented. A thorough comparison is carried out, taking into account the results of previous publications. Conclusions are duly drawn. (C) 2010 Elsevier Ltd. All rights reserved.

Balancing market integration in MASCEM electricity market simulator

With the restructuring of the energy sector in industrialized countries there is an increased complexity in market players’ interactions along with emerging problems and new issues to be addressed. Decision support tools that facilitate the study and understanding of these markets are extremely useful to provide players with competitive advantage. In this context arises MASCEM, a multi-agent simulator for competitive electricity markets. It is essential to reinforce MASCEM with the ability to recreate electricity markets reality in the fullest possible extent, making it able to simulate as many types of markets models and players as possible. This paper presents the development of the Balancing Market in MASCEM. A key module to the study of competitive electricity markets, as it has well defined and distinct characteristics previously implemented.

Dynamic artificial neural network for electricity market prices forecast

This paper presents an artificial neural network applied to the forecasting of electricity market prices, with the special feature of being dynamic. The dynamism is verified at two different levels. The first level is characterized as a re-training of the network in every iteration, so that the artificial neural network can able to consider the most recent data at all times, and constantly adapt itself to the most recent happenings. The second level considers the adaptation of the neural network’s execution time depending on the circumstances of its use. The execution time adaptation is performed through the automatic adjustment of the amount of data considered for training the network. This is an advantageous and indispensable feature for this neural network’s integration in ALBidS (Adaptive Learning strategic Bidding System), a multi-agent system that has the purpose of providing decision support to the market negotiating players of MASCEM (Multi-Agent Simulator of Competitive Electricity Markets).

A short-term risk management tool applied to OMEL electricity market using particle swarm optimization

Short-term risk management is highly dependent on long-term contractual decisions previously established; risk aversion factor of the agent and short-term price forecast accuracy. Trying to give answers to that problem, this paper provides a different approach for short-term risk management on electricity markets. Based on long-term contractual decisions and making use of a price range forecast method developed by the authors, the short-term risk management tool presented here has as main concern to find the optimal spot market strategies that a producer should have for a specific day in function of his risk aversion factor, with the objective to maximize the profits and simultaneously to practice the hedge against price market volatility. Due to the complexity of the optimization problem, the authors make use of Particle Swarm Optimization (PSO) to find the optimal solution. Results from realistic data, namely from OMEL electricity market, are presented and discussed in detail.