46 resultados para Validity over time
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This paper develops a model of a forest owner operating in an open-city environment, where the rent for developed land is increasing concave in nearby preserved open space and is rising over time reflecting an upward trend in households’ income. Thus, our model creates the possibility of switching from forestry to residential use at some point in the future. In addition it allows the optimal harvest length to vary over time even if stumpage prices and regeneration costs remain constant. Within this framework we examine how adjacent preserved open space and alternative development constraints affect the private landowner´s decisions. We find that in the presence of rising income, preserved open space hastens regeneration and conversion cuts but leads to lower density development of nearby unzoned parcels due to indirect dynamic effects. We also find that both a binding development moratorium and a binding minimum-lot-size policy can postpone regeneration and conversion cut dates and thus help to protect open space even if only temporarily. However, the policies do not have the same effects on development density of converted forestland. While the former leads to high-density development, the latter encourages low-density development.
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This paper aims at building a theoretical framework to examine the impact of development pressure on private owner’s forest management practices, namely, on regeneration and conversion cut dates. As the rent for developed land is rising over time, our model creates the possibility of switching from forestry to residential use at some point in the future, thus departing from the Faustmann’s traditional setup. Comparative statics results with respect to stumpage prices, regeneration costs and urban growth parameters are provided. The results obtained depend on the impact on the opportunity cost of holding the stand and the impact on the opportunity cost of holding the land, generalizing Faustmann’s unambiguous results.
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From 1995 to 2010 Portugal has accumulated a negative international asset position of 110 percent of GDP. In a developed and aging economy the number is astonishing and any argument to consider it sustainable must rely on extremely favorable forecasts on growth. Portuguese policy options are reduced in number: no autonomous monetary policy, no currency to devaluate, and limited discretion in changing fiscal deficits and government debt. To start the necessary deleveraging a remaining possible policy is a budget-neutral change of the tax structure that increases private saving and net exports. An increase in the VAT and a decrease in the employer’s social security contribution tax can achieve the desired outcome in the short run if they are complemented with wage moderation. To obtain a substantial improvement in competitiveness and a large decrease in consumption, the changes in the tax rates have to be large. While a precise quantitative assessment is difficult, the initial increase in the effective VAT rate needed to allow the social security tax to decrease by 16 percentage points (pp) is approximately 10 pp. Such a large increase in the effective VAT rate could be obtained by raising most of the reduced VAT rates to the new general VAT rate of 23 percent. The empirical analysis shows that over time the suggested tax swap could generate surpluses and improve the trade balance. A temporary version of the suggested tax-swap has the attractiveness to achieve a sharper increase in the private saving rate maintaining the short run gains in competitiveness. Finally, the temporary version of the fiscal devaluation could be the basis for an automatic stabilizer to external imbalances within a monetary union.Portugal has been running large current account deficits every year since 1995. These deficits have accumulated to an astonishing 110 percent of GDP negative external asset position. The sustainability of such a large external position is questionable and must rely on fantastic productivity growth expectations. The recent global financial crisis appears to have anticipated the international investors reality check on those future expectations with the result of a large increase in the cost of external financing. Today the rebalancing of the current account through an increase in national savings and an improvement in competitiveness must be at the top of the Portuguese authorities “to do” list as the cost of a pull out from international investors is of the order of 10% of GDP. The external rebalancing is difficult as the degrees of freedom of the Portuguese authorities are limited in number: they have no autonomous monetary policy, no currency to devaluate, and little discretion in fiscal policy as deficit limits and debt targets are set by the Stability Growth Pact and the postcrisis consensus on medium-term fiscal consolidation. One possibility that remains is to change the fiscal policy mix for a given budget deficit. The purpose of this paper is to explore the effects of a “fiscal devaluation”1 obtained through a tax swap between employers’ social security contributions and taxes on consumption2. The paper begins by illustrating Portugal’s current account evolution during the euro period. The second section section lays out a model to offer a qualitative assessment of the dynamic outcomes of the the tax swap. I show that the suggested tax swap can in theory achieve the desired outcomes in terms of competitiveness and consumption if complemented with moderation (stickiness) in wages. I also study the effects of a temporary version of the tax swap and show that it achieves a sharper improvement in the current account that accelerate the rebalancing. The third section moves to the empirical analysis and estimates the likely effects of the tax swap for the Portuguese economy. The fourth section concludes.
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Dissertação para obtenção do Grau de Mestre em Engenharia Informática
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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Economics from the NOVA – School of Business and Economics
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This paper illustrates how delayed debt stabilizations can arise in a society without any emerging conflict of interests among its members. We argue that, under a majority voting rule, the economy may generate excessive levels of government spending and larger debts over time, and that this delay is increasing in income inequality. The intuition for this result is simple: a majority of citizens may find in delaying stabilizations a way to increase government expenditures, transferring in this way resources from the richest to the poorest citizens in the economy. This process may explain the upward trend and the difficulty to reduce public expenditures, the so called "ratchet effect."
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Disponível em: http://193.136.113.6/Opac/Pages/Search/Results.aspx?SearchText=UID=bb8aa8d5-c6b6-466a-81bb-fe8a67693cee&DataBase=10449_UNLFCSH
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Dissertação apresentada para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores, pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia
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RESUMO: Introdução: A Comissão Nacional para a reestruturação dos Serviços de Saúde Mental em 2004, fez uma proposta de âmbito regional, ao nível da região de Saúde do Norte, levando a uma alteração da rede de referenciação hospitalar dos internamentos em psiquiatria. Métodos: Realizou-se um estudo epidemiológico longitudinal para avaliar factores preditivos de internamento através de um serviço de Urgência de Segunda Linha (SII), que de algum modo reflectisse o funcionamento dos serviços de internamento na região de Saúde do Norte, ao longo de 12 anos, nomeadamente relacionando com factores organizacionais contemplados no Plano Nacional de Saúde Mental e na reorganização da rede de referenciação hospitalar. Resultados: Durante os 12 anos do estudo, verificou-se um aumento estatisticamente significativo do número e duração de internamentos através do SII, com ponto de partida no ano 2008-2009, e de novo a partir do ano 2010-2011 (nº de internamentos), para o qual contribuiu a alteração da rede hospitalar na região de saúde do Norte, nomeadamente pelo facto do HMLemos, assumir a responsabilidade de novo, dos internamentos das áreas de Famalicão, Gondomar e Santa Maria da Feira. Em relação ao número de internamentos, e na análise exploratória, encontramos nas áreas hospitalares fora da área de influência do HMLemos, uma contribuição positiva significativa para o aumento do nº de internamentos ao longo dos anos com os Dx (290, 296, 297, 291, 309). Em relação à área do HMLemos restrita (PVC, STT, Matosinhos, Porto Ocidental), de referir a contribuição positiva significativa dos Dx 309 e 301, para o aumento do número de internamentos ao longo do tempo, sendo que a prevalência maior se mantém relacionada às Psicoses (Dx 295, 296 e 297). Não se concluiu por uma contribuição estatisticamente significativa ( positiva ou negativa), das variáveis independentes idade, sexo ou natureza do internamento em relação à variável dependente ( duração de internamentos/ano). Em relação á variável dependente (nº de internamentos/ano), relativamente aos doentes fora de área de influência do HMLemos, concluiu-se uma contribuição positiva estatisticamente significativa da variável independente idade. Conclusões: Através da análise exploratória foi possível perceber o esforço realizado pelos hospitais no sentido de melhorar a equidade e acessibilidade dos doentes à Saúde Mental, a par da reorganização da rede hospitalar. De destacar a necessidade de encontrar alternativas às situações de internamento, com menos critérios de gravidade diagnóstica, nomeadamente reforçar a importância da criação de consultas de crises nos respectivos Hospitais de Dia dos DPSM.----------------ABSTRACT:Introduction : The National Commission for the restructuring of mental health services in 2004 , has proposed at a regional level ( North Health Region), a change in the network of hospital referrals of admissions in psychiatry. Methods: We conducted a longitudinal epidemiological study to assess predictors of hospitalization through a Second Line Emergency Service ( SII) , that somehow reflect the operation of inpatient services in North Health Region, over 12 years, particularly relating to organizational factors included in the National Mental Health Plan and reorganization of the hospital referral network. Results: During the period of the study, there was a statistically significant increase in the number and duration of hospitalizations through the SII, with starting point in the year 2008-2009 and again from 2010-2011 (number of admissions) , for which counted the change of the hospital network referral in Northern health region , in particular because Hospital Magalhães Lemos (HMLemos) , took the new responsibility of admissions from areas of Famalicão, Gondomar and Santa Maria da Feira . Regarding the number of hospitalizations, in the exploratory analysis , we found in hospital areas outside the area of influence of HMLemos , a significant positive contribution to the increase in number of admissions over the years with Diagnosis of 290, 296, 297, 291 , 309 in the ICD-9. With respect to the restricted area of HMLemos (PVC, STT , Porto Ocidental and Matosinhos) , we found a significant positive contribution of Diagnosis 309 and 301, to increase the number of hospitalizations over time, with higher prevalence rates remaining the psychoses ( Dx 295, 296 and 297 ) . Did not conclude for any statistically significant contribution (positive or negative) of the independent variables age, sex and nature of admission to the dependent variable (duration of hospitalization / year). In relation to the dependent variable (number of admissions / year) relative to patients outside the area of influence of HMLemos, it was found a statistically significant positive contribution of the independent variable age . Conclusions: Through the exploratory analysis, it was possible to see the efforts made by hospitals to improve the accessibility of patients to Mental Health, throughout the hospital network reorganization. Its important to highlight the need to find alternatives to inpatient admissions in those with less gravity diagnostic criteria, reinforcing the importance of creating specific crisis consultations in Day Hospital regime.
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This Work Project investigates the determinants of reelection using data on the 278 Portuguese mainland municipalities for the period 1976-2009. We implement a logit fixed effect model to control for the municipalities’ unobserved characteristics that remain constant over time. Political variables, such as the vote share of the incumbent’s party in previous election, the number of mayor’s consecutive mandates and abstention rate, are found to be relevant in explaining incumbent’s reelection. Moreover, as to the mayor’s individual characteristics, age and education contribute to explain reelection prospects. We also provide weak evidence that a higher degree of fiscal autonomy increases political turnover and that the good economic prospects of the municipality positively affect reelection. Finally, the residents’ level of education and the size of the municipal population have an explanatory power on mayor’s reelection. We perform several robustness checks to confirm these results.
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Versão online da Revista Brasileira de Estudos Políticos, Belo Horizonte, nº 107, pp. 149-200, jul./dez.2013
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Também publicado em DELGADO, José Pina (org.) e SILVA, Mário Ramos Pereira (org.) "Estudos em Comemoração do XXº Aniversário da Constituição da República de Cabo Verde", Praia: Edições do ISCJS, 2013, [9]-29 pp
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Partindo dos dispositivos jurídicos em vigor (Código Civil e Regulamento Geral das Edificações Urbanas) e recuando até às antigas influências jurídicas (romanas e islâmicas), neste artigo procura-se perceber como os interstícios entre prédios em Portugal foram estabelecidos ao longo do tempo pela ordem jurídica. São contextualizadas e analisadas as antigas normas da almotaçaria e as normas contemporâneas, procurando perceber inovações e persistências. Por fim, realça-se a importância deste conhecimento para o estudo da forma urbana portuguesa.
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The momentum anomaly has been widely documented in the literature. However, there are still many issues where there is no consensus and puzzles left unexplained. One is that strategies based on momentum present a level of risk that is inconsistent with the diversification that it offers. Moreover, recent studies indicate that this risk is variable over time and mostly strategy-specific. This work project hypothesises and proves that this evidence is explained by the portfolio constitution of the momentum strategy over time, namely the covariance and correlation between companies in the top and down deciles and across them.
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This paper is mainly concerned with the tracking accuracy of Exchange Traded Funds (ETFs) listed on the London Stock Exchange (LSE) but also evaluates their performance and pricing efficiency. The findings show that ETFs offer virtually the same return but exhibit higher volatility than their benchmark. It seems that the pricing efficiency, which should come from the creation and redemption process, does not fully hold as equity ETFs show consistent price premiums. The tracking error of the funds is generally small and is decreasing over time. The risk of the ETF, daily price volatility and the total expense ratio explain a large part of the tracking error. Trading volume, fund size, bid-ask spread and average price premium or discount did not have an impact on the tracking error. Finally, it is concluded that market volatility and the tracking error are positively correlated.