Browsing by Issue Date, starting with "2012-08"
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- Equilibrium existence in infinite horizon economiesPublication . Moreno-García, Emma; Torres-Martínez, Juan PabloIn sequential economies with finite or infinite-lived real assets in positive net supply, we introduce constraints on the amount of borrowing in terms of the market value of physical endowments. We show that, when utility functions are either unbounded and separable in states of nature or separable in commodities, these borrowing constraints not only preclude Ponzi schemes but also induce endogenous Radner bounds on short-sales. Therefore, we obtain existence of equilibrium. Moreover, equilibrium also exists when both assets are numéraire and utility functions are quasilinear in the commodity used as numéraire.
- Evaluating risks in public private partnerships : the case of the portuguese road sectorPublication . Fernandes, Mário Jorge Correia; Sarmento, JoaquimThroughout the last few decades, it has been verified a significant raise in the use of Public-Private Partnerships, by part of the world’s economic governments as an alternative in the management and financing of infrastructural investments to joust the problematic of the infrastructure gap. From the projects sponsors point of view, the capital investment's strategic decisions are fundamental, so that the feasibility studies of partnerships are a critical factor for operational success and their management. However, for these agents, the risk-return question is preponderant, due to the soaring of financial, political and market risks, which will organize the imperative of application of new evaluation methods, as the case of the IRR-at-Risk, Cash Flow-at-Risk and the NPV-at-Risk, where the latter combines the dual issue of risk-return and the average weighted cost of capital. Therefore, this investigation aims to proceed to the application of the listed methods for the Public-Private road institutions in Portugal. Based in a sample from the 7 SCUT and 7 new concessions (highways), we will seek to apply the decision methods of risk-return in order to prove that these can provide better decisions in matters of risk and investments analysis compared to the methods of traditional financial evaluation. The results show that, for the sponsors, the methods of risk-return provides better decisions if include the element of risk in projects.
- The transition of people’s preferences for the intervention of the government in the economy of re-unified GermanyPublication . Migheli, MatteoCovering the first fifteen years immediately after German re- unification, this paper analyzes the people’s support to the transition. The focus is on individuals’ preferences for the intervention of the government in the economy and on the opinion about competition per se. Eastern German data are compared with Western German data. Using suitable data that allow for interpersonal comparisons, the paper shows that Eastern Germans have always preferred an intervention of the public hand in the economy deeper than Western Germans; these different positions have hardly converged during the examined period of time. However there are no significant differences with respect to how Germans perceive competition per se: it is considered as a good by the people living in both parts of the country.
- Social security and economic performance in Portugal : after all that has been said and done how much has actually changed?Publication . Pereira, Alfredo M.; Andraz, Jorge M.This paper provides an empirical estimate of the macroeconomic effects of the Portuguese pay-as-you-go social security system based on data for the period 1970–2007 and on VAR estimates using GDP, the unit cost of labor, the unemployment rate, the savings rate and social security spending. The major findings are twofold. First, growing social security spending has had detrimental effects on all of the private sector variables under consideration suggesting the existence of sizable inefficiencies. Second, these inefficiencies persist despite the successive reforms that took place over the last two decades. These results highlight the need for structural reforms of the pay-as-you-go system thereby addressing the sources of these inefficiencies, regardless of whether or not the system is financially sustainable. Furthermore, any reforms designed to address sustainability concerns cannot ignore these inefficiencies or risk making them even worse and thereby hindering the quest for sustain- ability itself.
- Segmentação da rede convencionadaPublication . Raimundo, José Carlos Alves; Barroso, Maria de Nazaré; Bandeira, Maria do CarmoA disparidade existente entre os prestadores da Rede Convencionada (RC) em vários indicadores inerentes aos serviços médicos prestados a clientes Multicare, dificulta uma melhor eficiência em todo o processo de monitorização de custos realizado pelo Gabinete de Atuariado e Controle (GAC). Este relatório baseia-se na segmentação da RC da Multicare em grupos de prestadores homogéneos, no âmbito da cobertura de Internamento, alinhando-se aos objetivos primordiais da área de estudos estatísticos do GAC. Para tal, recorre-se a uma técnica estatística denominada de Análise de Clusters (AC), permitindo aferir um conjunto de conclusões sobre o comportamento de cada um dos grupos formados. Foram recolhidas 23 720 autorizações de serviços médicos prestados a segurados com coberturas Managed Care (MC) ou mistas, que reportam para um conjunto de 49 prestadores. As variáveis utilizadas resultam da informação dos atos médicos prestados em cada um dos prestadores selecionados. Ao nível da AC foram utilizados dois métodos distintos, primeiramente um hierárquico para definir o número ótimo de clusters a reter e, seguidamente, um não hierárquico com o intuito de otimizar a solução obtida no método anterior. Os resultados alcançados demonstram que existem três agrupamentos de prestadores homogéneos, nos quais dos 49 prestadores selecionados, 36 foram alocados nos mesmos clusters por ambos os métodos. O cluster 1 apresenta uma elevada taxa de ocorrência de cirurgias e valores medianos nas restantes variáveis; o cluster 2 ilustra uma elevada taxa de cirurgias, inversamente ao número de clientes, à quantidade de autorizações em todos os códigos-macro e aos custos médios (por cliente, de atos não empacotados, de cirurgias e de todos os códigos-macro) que apresentam todos eles valores baixos; por último, no cluster 3 agruparam-se Unidades Hospitalares de grande relevância da RC da Multicare, espelhadas na sua generalidade por baixas taxas de cirurgias, elevado número de autorizações e custos médios também elevados.
- House prices and monetary policyPublication . Brito, Paulo; Marini, Giancarlo; Piergallini, AlessandroThis paper analyzes global dynamics in an overlapping generations general equilibrium model with housing-wealth effects. It shows that monetary policy cannot burst rational bubbles in the housing market. Under monetary policy rules of the Taylor-type, there exist global self-fulfilling paths of house prices along a heteroclinic orbit connecting multiple equilibria. From bifurcation analysis, the orbit features a boom (bust) in house prices when monetary policy is more (less) active. The paper also demonstrates that boom or busts cannot be ruled out by interest-rate feedback rules responding to both inflation and house prices.
- Asymmetry, realised volatility and stock return risk estimatesPublication . Grané, Aurea; Veiga, HelenaIn this paper we estimate minimum capital risk requirements for short and long positions with three investment horizons, using the traditional GARCH model and two other GARCH-type models that incorporate the possibility of asymmetric responses of volatility to price changes. We also address the problem of the extremely high estimated persistence of the GARCH model to generate observed volatility patterns by including realised volatility as an explanatory variable into the model’s variance equation. The results suggest that the inclusion of realised volatility improves the GARCH forecastability as well as its ability to calculate accurate minimum capital risk requirements and makes it quite competitive when compared with asymmetric conditional heteroscedastic models such as the GJR and the EGARCH.
- Considerações sobre uma Ideia de Teatro PopularPublication . Filipe, GuilhermeReflexões sobre um conceito de difícil definição, o de Teatro Popular. Análise sobre o conceito de Teatro, enquanto Arte, Entretenimento e actividade Comercial, procura-se chegar à conclusão de que Teatro Popular é mais uma categoria sociológica do que estética.
- Considerações sobre uma Ideia de Teatro PopularPublication . Filipe, GuilhermeReflexões sobre o conceito de Teatro Popular de difícil definição. Breve perspectiva sobre o Teatro enquanto Arte, Entretenimento e actividade Comercial: uma controvérsia de difícil resolução, uma categoria mais sociológica do que estética.
- Technopolitic: sophistication and new dichotomiesPublication . FSA; Ferraz de Abreu, P.In the following paper we observe one of the impacts of the new TICs in the context of the recent riots. In particular, we show a few examples where is possible to realize how Governments are experimenting a process of enabling and sophistication, and how TICs could be considered not only a a medium of democratization, but also a new tools of repression in autocratic contexts. Moreover considering the new cooperation between Internet provider and government agencies, we report new issues which must be studied with the aim to improve the structure of the Internet.