Testing the long-run implications of the expectation hypothesis using cointegration techniques with structural change

This paper investigates whether or not multivariate cointegrated process with structural change can describe the Brazilian term structure of interest rate data from 1995 to 2006. In this work the break point and the number of cointegrated vector are assumed to be known. The estimated model has four regimes. Only three of them are statistically different. The first starts at the beginning of the sample and goes until September of 1997. The second starts at October of 1997 until December of 1998. The third starts at January of 1999 and goes until the end of the sample. It is used monthly data. Models that allows for some similarities across the regimes are also estimated and tested. The models are estimated using the Generalized Reduced-Rank Regressions developed by Hansen (2003). All imposed restrictions can be tested using likelihood ratio test with standard asymptotic 1 qui-squared distribution. The results of the paper show evidence in favor of the long run implications of the expectation hypothesis for Brazil.

Economic recovery from the Argentine great depression : institutions, expectations, and the change of macroeconomic regime

This work explores how Argentina overcame the Great Depression and asks whether active macroeconomic interventions made any contribution to the recovery. In particular, we study Argentine macroeconomic policy as it deviated from gold-standard orthodoxy after the final suspension of convertibility in 1929. As elsewhere, fiscal policy in Argentina was conservative, and had little power to smooth output. Monetary policy became heterodox after 1929. The first and most important stage of institutional change took place with the switch from a metallic monetary regime to a fiduciary regime in 1931; the Caja de Conversi��n (Conversion Office, a currency board) began rediscounting as a means to sterilize gold outflows and avoid deflationary pressures, thus breaking from orthodox "mIes of the game." However, the actual injections of liquidity were small' and were not enough to fully offset the incipient monetary contractions: the "Keynes" effect was weak or negative. Rather, recovery derived from changes in beliefs and expectations surrounding the shift in the monetary and exchange-rate regime,and the delinking of gold flows and the money base. Agents perceivod a new regime, as shown by the path of consumption, investment, and estimated ex ante real interest rates: the "Mundell" effect was dominant. Notably, this change of regime predated a later, and supposedly more significant, stage of institutional reform, namely the creation of the central bank in 1935. Still, the extent of intervention was weak, and insufficient to fully offset externaI shocks to prices and money. Argentine macropolicy was heterodox in terms of the change of regime, but still conservative in terms of the tentative scope of the measures taken .

Non-Parametric Tests of Real Exchange rates in the Post-Bretton Woods Era

This paper examines the mean-reverting property of real exchange rates. Earlier studies have generally not been able to reject the null hypothesis of a unit-root in real exchange rates, especially for the post-Bretton Woods floating period. The results imply that long-run purchasing power parity does not hold. More recent studies, especially those using panel unit-root tests, have found more favorable results, however. But, Karlsson and L��thgren (2000) and others have recently pointed out several potential pitfalls of panel unit-root tests. Thus, the panel unit-root test results are suggestive, but they are far from conclusive. Moreover, consistent individual country time series evidence that supports long-run purchasing power parity continues to be scarce. In this paper, we test for long memory using Lo's (1991) modified rescaled range test, and the rescaled variance test of Giraitis, Kokoszka, Leipus, and Teyssi��re (2003). Our testing procedure provides a non-parametric alternative to the parametric tests commonly used in this literature. Our data set consists of monthly observations from April 1973 to April 2001 of the G-7 countries in the OECD. Our two tests find conflicting results when we use U.S. dollar real exchange rates. However, when non-U.S. dollar real exchange rates are used, we find only two cases out of fifteen where the null hypothesis of an unit-root with short-term dependence can be rejected in favor of the alternative hypothesis of long-term dependence using the modified rescaled range test, and only one case when using the rescaled variance test. Our results therefore provide a contrast to the recent favorable panel unit-root test results.

Saving for Retirement and Investing for Growth. Report of the CEPS-RCMI Task Force on Long-term Investing and Retirement Savings. CEPS Task Force Report, September 2013

Europe is facing a double challenge: a significant need for long-term investments ��� crucial levers for economic growth ��� and a growing pension gap, both of which call for resolute action. Crucially, at a time when low interest rates and revised prudential standards strain the ability of life insurers and pension funds to offer guaranteed returns, Europe lacks a framework ensuring the quality and accessibility of long-term investment solutions for small retail investors and defined contribution pension plans. This report considers the potential to steer household financial wealth ��� accounting for over 60% of total financial wealth in Europe ��� towards long-term investing, which would achieve two goals at once: higher growth and higher pensions. It follows a holistic approach that considers both solution design ��� how to gear product structuring towards long-term investing ��� and market structure ��� how to engineer a competitive market setting that is able to deliver high-quality and cost-efficient solutions. The report also considers prudential rules for insurers and pension funds and the potential to build a single market for less-liquid funds, occupational and personal pensions, with improved investor protection. It urges policy-makers to act aggressively to deliver more inclusive, efficient and resilient retail investment markets that are better equipped and more committed to deliver value over the long-term for beneficiaries.

Evidence of the heterogeneous market hypothesis using wavelet multi -resolution analysis

In finance literature many economic theories and models have been proposed to explain and estimate the relationship between risk and return. Assuming risk averseness and rational behavior on part of the investor, the models are developed which are supposed to help in forming efficient portfolios that either maximize (minimize) the expected rate of return (risk) for a given level of risk (rates of return). One of the most used models to form these efficient portfolios is the Sharpe's Capital Asset Pricing Model (CAPM). In the development of this model it is assumed that the investors have homogeneous expectations about the future probability distribution of the rates of return. That is, every investor assumes the same values of the parameters of the probability distribution. Likewise financial volatility homogeneity is commonly assumed, where volatility is taken as investment risk which is usually measured by the variance of the rates of return. Typically the square root of the variance is used to define financial volatility, furthermore it is also often assumed that the data generating process is made of independent and identically distributed random variables. This again implies that financial volatility is measured from homogeneous time series with stationary parameters. In this dissertation, we investigate the assumptions of homogeneity of market agents and provide evidence for the case of heterogeneity in market participants' information, objectives, and expectations about the parameters of the probability distribution of prices as given by the differences in the empirical distributions corresponding to different time scales, which in this study are associated with different classes of investors, as well as demonstrate that statistical properties of the underlying data generating processes including the volatility in the rates of return are quite heterogeneous. In other words, we provide empirical evidence against the traditional views about homogeneity using non-parametric wavelet analysis on trading data, The results show heterogeneity of financial volatility at different time scales, and time-scale is one of the most important aspects in which trading behavior differs. In fact we conclude that heterogeneity as posited by the Heterogeneous Markets Hypothesis is the norm and not the exception.

Forecasting exchange rates in the presence of instabilities

Many exchange rate papers articulate the view that instabilities constitute a major impediment to exchange rate predictability. In this thesis we implement Bayesian and other techniques to account for such instabilities, and examine some of the main obstacles to exchange rate models' predictive ability. We first consider in Chapter 2 a time-varying parameter model in which fluctuations in exchange rates are related to short-term nominal interest rates ensuing from monetary policy rules, such as Taylor rules. Unlike the existing exchange rate studies, the parameters of our Taylor rules are allowed to change over time, in light of the widespread evidence of shifts in fundamentals - for example in the aftermath of the Global Financial Crisis. Focusing on quarterly data frequency from the crisis, we detect forecast improvements upon a random walk (RW) benchmark for at least half, and for as many as seven out of 10, of the currencies considered. Results are stronger when we allow the time-varying parameters of the Taylor rules to differ between countries. In Chapter 3 we look closely at the role of time-variation in parameters and other sources of uncertainty in hindering exchange rate models' predictive power. We apply a Bayesian setup that incorporates the notion that the relevant set of exchange rate determinants and their corresponding coefficients, change over time. Using statistical and economic measures of performance, we first find that predictive models which allow for sudden, rather than smooth, changes in the coefficients yield significant forecast improvements and economic gains at horizons beyond 1-month. At shorter horizons, however, our methods fail to forecast better than the RW. And we identify uncertainty in coefficients' estimation and uncertainty about the precise degree of coefficients variability to incorporate in the models, as the main factors obstructing predictive ability. Chapter 4 focus on the problem of the time-varying predictive ability of economic fundamentals for exchange rates. It uses bootstrap-based methods to uncover the time-specific conditioning information for predicting fluctuations in exchange rates. Employing several metrics for statistical and economic evaluation of forecasting performance, we find that our approach based on pre-selecting and validating fundamentals across bootstrap replications generates more accurate forecasts than the RW. The approach, known as bumping, robustly reveals parsimonious models with out-of-sample predictive power at 1-month horizon; and outperforms alternative methods, including Bayesian, bagging, and standard forecast combinations. Chapter 5 exploits the predictive content of daily commodity prices for monthly commodity-currency exchange rates. It builds on the idea that the effect of daily commodity price fluctuations on commodity currencies is short-lived, and therefore harder to pin down at low frequencies. Using MIxed DAta Sampling (MIDAS) models, and Bayesian estimation methods to account for time-variation in predictive ability, the chapter demonstrates the usefulness of suitably exploiting such short-lived effects in improving exchange rate forecasts. It further shows that the usual low-frequency predictors, such as money supplies and interest rates differentials, typically receive little support from the data at monthly frequency, whereas MIDAS models featuring daily commodity prices are highly likely. The chapter also introduces the random walk Metropolis-Hastings technique as a new tool to estimate MIDAS regressions.

An empirical evaluation of imputation accuracy for association statistics reveals increased type-I error rates in genome-wide associations

Background: Genome wide association studies (GWAS) are becoming the approach of choice to identify genetic determinants of complex phenotypes and common diseases. The astonishing amount of generated data and the use of distinct genotyping platforms with variable genomic coverage are still analytical challenges. Imputation algorithms combine directly genotyped markers information with haplotypic structure for the population of interest for the inference of a badly genotyped or missing marker and are considered a near zero cost approach to allow the comparison and combination of data generated in different studies. Several reports stated that imputed markers have an overall acceptable accuracy but no published report has performed a pair wise comparison of imputed and empiric association statistics of a complete set of GWAS markers. Results: In this report we identified a total of 73 imputed markers that yielded a nominally statistically significant association at P < 10(-5) for type 2 Diabetes Mellitus and compared them with results obtained based on empirical allelic frequencies. Interestingly, despite their overall high correlation, association statistics based on imputed frequencies were discordant in 35 of the 73 (47%) associated markers, considerably inflating the type I error rate of imputed markers. We comprehensively tested several quality thresholds, the haplotypic structure underlying imputed markers and the use of flanking markers as predictors of inaccurate association statistics derived from imputed markers. Conclusions: Our results suggest that association statistics from imputed markers showing specific MAF (Minor Allele Frequencies) range, located in weak linkage disequilibrium blocks or strongly deviating from local patterns of association are prone to have inflated false positive association signals. The present study highlights the potential of imputation procedures and proposes simple procedures for selecting the best imputed markers for follow-up genotyping studies.

Short- and long-term survival of patients with metastatic solid cancer admitted to the intensive care unit: prognostic factors

Decisions for intensive care unit (ICU) admissions in patients with advanced cancer are complex, and the knowledge of survival rates and prognostic factors are essential to these decisions. Ours objectives were to describe the short- and long-term survival of patients with metastatic solid cancer admitted to an ICU due to emergencies and to study the prognostic factors presented at ICU admission that could be associated with hospital mortality. We retrospectively analysed the charts of all patients with metastatic solid cancer admitted over a 1-year period. This gave a study sample of 83 patients. The ICU, hospital, 1-year and 2-year survival rates were 55.4%, 28.9%, 12.0% and 2.4% respectively. Thrombocytopenia (odds ratio 26.2; P = 0.006) and simplified acute physiology score (SAPS II) (odds ratio 1.09; P = 0.026) were independent factors associated with higher hospital mortality. In conclusion, the survival rates of patients with metastatic solid cancer admitted to the ICU due to emergencies were low, but of the same magnitude as other groups of cancer patients admitted to the ICU. The SAPS II score and thrombocytopenia on admission were associated with higher hospital mortality. The characteristics of the metastatic disease, such as number of organs with metastasis and central nervous system metastasis were not associated with the hospital mortality.

Long-term stability of dentin matrix following treatment with various natural collagen cross-linkers

Objectives: Collagen disorganization is one of the main degradation patterns found in unsuccessful adhesive restorations. The hypothesis of this study was that pretreatment using natural collagen cross-linking agents rich in proanthocyanidin (PA) would improve mechanical properties and stability over time of the dentin collagen and, thus, confer a more resistant and lasting substrate for adhesive restorations. Methods: PA-based extracts, from grape seed (GSE), cocoa seed (CSE), cranberry (CRE), cinnamon (CNE) and acai berry (ACE) were applied over the demineralized dentin. The apparent elastic modulus (E) of the treated dentin collagen was analyzed over a 12 month period. Specimens were immersed in the respective solution and E values were obtained by a micro-flexural test at baseline, 10, 30, 60, 120 and 240 min. Samples were stored in artificial saliva and re-tested after 3, 6 and 12 months. Data was analyzed using ANOVA and Tukey test. Results: GSE and CSE extracts showed a time-dependent effect and were able to improve [240 min (MPa): GSE = 108.96 +/- 56.08: CSE = 59.21 +/- 24.87] and stabilize the E of the organic matrix [12 months (MPa): GSE = 40.91 +/- 19.69; CSE = 42.11 +/- 13.46]. CRE and CNE extracts were able to maintain the E of collagen matrices constant over 12 months [CRE = 11.17 +/- 7.22; CNE = 9.96 +/- 6.11; MPa]. ACE (2.64 +/- 1.22 MPa) and control groups immersed in neat distilled water (1.37 +/- 0.69 MPa) and ethanol-water (0.95 +/- 0.33 MPa) showed no effect over dentin organic matrix and enable their degradation and reduction of mechanical properties. Significance: Some PA-based extracts were capable of improving and stabilizing collagen matrices through exogenous cross-links induction. (C) 2011 Elsevier Ltd. All rights reserved.

Long-Term Effects of Specific Stabilizing Exercises for First-Episode Low Back Pain

Study Design. A randomized clinical trial with 1-year and 3-year telephone questionnaire follow-ups. Objective. To report a specific exercise intervention���s long-term effects on recurrence rates in acute, first-episode low back pain patients. Summary of Background Data. The pain and disability associated with an initial episode of acute low back pain (LBP) is known to resolve spontaneously in the short-term in the majority of cases. However, the recurrence rate is high, and recurrent disabling episodes remain one of the most costly problems in LBP. A deficit in the multifidus muscle has been identified in acute LBP patients, and does not resolve spontaneously on resolution of painful symptoms and resumption of normal activity. Any relation between this deficit and recurrence rate was investigated in the long-term. Methods. Thirty-nine patients with acute, first-episode LBP were medically managed and randomly allocated to either a control group or specific exercise group. Medical management included advice and use of medications. Intervention consisted of exercises aimed at rehabilitating the multifidus in cocontraction with the transversus abdominis muscle. One year and three years after treatment, telephone questionnaires were conducted with patients. Results. Questionnaire results revealed that patients from the specific exercise group experienced fewer recurrences of LBP than patients from the control group. One year after treatment, specific exercise group recurrence was 30%, and control group recurrence was 84% (P , 0.001). Two to three years after treatment, specific exercise group recurrence was 35%, and control group recurrence was 75% (P , 0.01). Conclusion. Long-term results suggest that specific exercise therapy in addition to medical management and resumption of normal activity may be more effective in reducing low back pain recurrences than medical management and normal activity alone. [Key Words: multifidus, low back pain, rehabilitation]

Rheo-NMR study of water-based cellulose liquid crystal system at high shear rates

Since long ago cellulosic lyotropic liquid crystals were thought as potential materials to produce fibers competitive with spidersilk or Kevlar, yet the processing of high modulus materials from cellulose-based precursors was hampered by their complex rheological behavior. In this work, by using the Rheo-NMR technique, which combines deuterium NMR with rheology, we investigate the high shear rate regimes that may be of interest to the industrial processing of these materials. Whereas the low shear rate regimes were already investigated by this technique in different works [1-4], the high shear rates range is still lacking a detailed study. This work focuses on the orientational order in the system both under shear and subsequent relaxation process arising after shear cessation through the analysis of deuterium spectra from the deuterated solvent water. At the analyzed shear rates the cholesteric order is suppressed and a flow-aligned nematic is observed which for the higher shear rates develops after certain time periodic perturbations that transiently annihilate the order in the system. During relaxation the flow aligned nematic starts losing order due to the onset of the cholesteric helices leading to a period of very low order where cholesteric helices with different orientations are forming from the aligned nematic, followed in the final stage by an increase in order at long relaxation times corresponding to the development of aligned cholesteric domains. This study sheds light on the complex rheological behavior of chiral nematic cellulose-based systems and opens ways to improve its processing. (C) 2015 Elsevier Ltd. All rights reserved.

Aconselhamento m��dico na preven����o da doen��a e promo����o da sa��de : an��lise a prop��sito do consumo de tabaco

RESUMO - O consumo de tabaco foi respons��vel por 100 milh��es de mortes no s��culo XX. Apesar dos grandes avan��os alcan��ados no controlo deste problema a n��vel mundial, sob os ausp��cios da OMS, no contexto da Conven����o-Quadro para o Controlo do Tabaco da OMS, se n��o forem adoptadas medidas consistentes e efectivas de sa��de p��blica, a morbi-mortalidade que lhe est�� associada continuar�� a aumentar durante o presente s��culo. A promo����o da cessa����o tab��gica constitui a estrat��gia populacional que permitir�� obter ganhos em sa��de a mais curto prazo. Embora a larga maioria dos fumadores fa��a, ao longo da vida, v��rias tentativas para parar de fumar sem apoio, apenas uma pequena minoria consegue manter-se abstinente a longo prazo. Os m��dicos de Medicina Geral e Familiar s��o, de entre todos os profissionais de sa��de, os que podem intervir de modo mais consistente e efectivo neste ��mbito e que melhores resultados obt��m na cessa����o tab��gica dos pacientes fumadores, dado o v��nculo terap��utico e a interac����o frequente e continuada que com eles estabelecem ao longo do seu ciclo de vida. O aconselhamento breve, tendo por base a adop����o de um estilo de comunica����o motivacional centrado no paciente, adaptado aos est��dios de mudan��a comportamental, tem-se revelado efectivo no apoio �� mudan��a de comportamentos relacionados com a sa��de e �� resolu����o da ambival��ncia que caracteriza este processo. A revis��o de literatura evidenciou o facto de os m��dicos nem sempre intervirem nas ��reas preventivas e de promo����o da sa��de, em particular na ��rea da cessa����o tab��gica, com o investimento e a continuidade desej��veis. Por outro lado, muitos pacientes fumadores referem nunca ter sido aconselhados pelo seu m��dico a deixar de fumar.. N��o s��o conhecidos estudos de ��mbito nacional que permitam conhecer esta realidade, bem como os factores associados ��s melhores pr��ticas de interven����o ou as barreiras sentidas pelos m��dicos de MGF �� actua����o nesta ��rea. O presente trabalho teve como objectivos: (i) avaliar a hip��tese de que os m��dicos que disseram adoptar o m��todo cl��nico centrado no paciente teriam atitudes mais favor��veis relativamente �� cessa����o tab��gica e uma maior probabilidade de aconselhar os seus pacientes a parar de fumar; (ii) estudar a rela����o entre as atitudes, a percep����o de auto-efic��cia, a expectativa de efectividade e as pr��ticas de aconselhamento sobre cessa����o tab��gica, auto-referidas pelos m��dicos; (iii) Identificar as vari��veis preditivas da adop����o de interven����es breves de aconselhamento adaptadas ao est��dio de mudan��a comportamental dos pacientes fumadores; (iv) identificar as barreiras e os incentivos �� adop����o de boas pr��ticas de aconselhamento nesta ��rea. A popula����o de estudo foi constitu��da pelo total de m��dicos de medicina geral e familiar inscritos na Associa����o Portuguesa de M��dicos de Cl��nica Geral, residentes em Portugal. Para recolha de informa����o, foi utilizado um question��rio de resposta an��nima, de autopreenchimento, aplicado por via postal a 2942 m��dicos, em duas s��ries de envio. O question��rio integrou perguntas fechadas, semifechadas, escalas de tipo Likert e escalas de tipo visual anal��gico. Para avalia����o da adop����o do m��todo cl��nico centrado no paciente, foi usada a Patient Practitioner Orientation Scale (PPOS). O tratamento estat��stico dos dados foi efectuado com o Programa PASW Statistics (ex-SPSS), vers��o 18. Foram utilizados: o ��ndice de �� de Cronbach, diversos testes n��o param��tricos e a an��lise de regress��o log��stica bin��ria. Foi obtida uma taxa de resposta de 22,4%. Foram analisadas 639 respostas (67,4% de mulheres e 32,6% de homens). Referiram ser fumadores 23% dos homens e 14% das mulheres. Foi identificada uma grande car��ncia formativa em cessa����o tab��gica, tendo apenas 4% dos m��dicos afirmado n��o necessitar de forma����o nesta ��rea. Responderam necessitar de forma����o em entrevista motivacional 66%, em preven����o da reca��da 59%, de treino numa consulta de apoio intensivo 55%, em interven����o breve 54% e em terap��utica farmacol��gica 55%. Cerca de 92% dos respondentes consideraram que o aconselhamento para a cessa����o tab��gica �� uma tarefa que faz parte das suas atribui����es, mas apenas 76% concordaram totalmente com a realiza����o de uma abordagem oportun��stica deste assunto em todos os contactos com os seus pacientes. Como pr��tica mais frequente, perante um paciente em prepara����o para parar, 85% dos m��dicos disseram tomar a iniciativa de aconselhar, 79% avaliar a motiva����o, 67% avaliar o grau de depend��ncia, 60% marcar o ���dia D��� e 50% propor terap��utica farmacol��gica. Apenas 21% assumiram realizar com frequ��ncia uma interven����o breve com pacientes em prepara����o (5 ��s); 13% uma interven����o motivacional com pacientes n��o motivados para mudar (5 Rs) e 20% uma interven����o segundo os princ��pios da entrevista motivacional, relativamente a pacientes ambivalentes em rela����o �� mudan��a. A an��lise multivariada de regress��o log��stica permitiu concluir que as vari��veis com maior influ��ncia na decis��o de aconselhar os pacientes sobre cessa����o tab��gica foram a percep����o de auto-efic��cia, o n��vel de atitudes negativas, a adop����o habitual do Programa-tipo de cessa����o tab��gica da DGS, a posse de forma����o espec��fica nesta ��rea e a n��o identifica����o de barreiras ao aconselhamento, em particular organizacionais ou ligadas ao processo de comunica����o na consulta. Embora se tenha confirmado a exist��ncia de associa����o entre a adop����o do m��todo cl��nico centrado no paciente e as atitudes face �� cessa����o tab��gica, n��o foi poss��vel confirmar plenamente a associa����o entre a adop����o deste m��todo e as pr��ticas autoreferidas de aconselhamento. Os m��dicos que manifestaram um n��vel baixo ou moderado de atitudes negativas, uma percep����o elevada de auto-efic��cia, que nunca fumaram, que referiram adoptar o Programa-tipo de cessa����o tab��gica e que n��o identificaram barreiras organizacionais apresentaram uma maior probabilidade de realizar uma interven����o breve (���5 ��s���) de aconselhamento de pacientes fumadores em prepara����o para parar de fumar. Nunca ter fumado apresentou-se associado a uma probabilidade de realizar uma interven����o breve (���5 ��s���) com frequ��ncia, superior �� verificada entre os m��dicos que referiram ser fumadores (Odds-ratio ajustado = 2,6; IC a 95%: 1,1; 5,7). Os m��dicos com o n��vel de auto-efic��cia no aconselhamento mais elevado apresentaram uma probabilidade superior �� encontrada entre os m��dicos com o menor n��vel de auto-efic��cia de realizar com frequ��ncia uma interven����o breve de aconselhamento, integrando as cinco vertentes dos ���5 ��s��� (Odds ratio ajustado = 2,6; IC a 95%: 1,3; 5,3); de realizar uma interven����o motivacional breve com fumadores renitentes a parar de fumar (Odds ratio ajustado = 3,1; IC a 95%: 1,4; 6,5) ou de realizar com frequ��ncia uma interven����o motivacional com pacientes em est��dio de ambival��ncia (Odds ratio = 8,8; IC a 95%: 3,8; 19,9). A falta de tempo, a falta de forma����o espec��fica e a falta de equipa de apoio foram as barreiras ao aconselhamento mais citadas. Como factores facilitadores de um maior investimento nesta ��rea, cerca de 60% dos m��dicos referiram a realiza����o de um est��gio pr��tico de forma����o; 57% a possibilidade de dispor do apoio de outros profissionais; cerca de metade a melhoria da sua forma����o te��rica. Cerca de 25% dos m��dicos investiria mais em cessa����o tab��gica se dispusesse de um incentivo financeiro e 20% se os pacientes demonstrassem maior interesse em discutir o assunto ou existisse uma maior valoriza����o desta ��rea por parte dos colegas e dos ��rg��os de gest��o. As limita����es de representatividade da amostra, decorrentes da taxa de resposta obtida, imp��em reservas �� possibilidade de extrapola����o destes resultados para a popula����o de estudo, sendo de admitir que os respondentes possam corresponder aos m��dicos mais interessados por este tema e que optam por n��o fumar. Outra importante limita����o adv��m do facto de n��o ter sido estudada a vertente relativa aos pacientes, no que se refere ��s suas atitudes, percep����es e expectativas quanto �� actua����o do m��dico neste campo. Pesem embora estas limita����es, os resultados obtidos revelaram uma grande perda de oportunidades de preven����o da doen��a e de promo����o da sa��de. Parece ter ficado demonstrada a importante influ��ncia que as atitudes, em especial as negativas, e as percep����es, em particular a percep����o de auto-efic��cia, podem exercer sobre as pr��ticas de aconselhamento auto-referidas. Todavia, ser�� necess��rio aprofundar os resultados agora encontrados com estudos de natureza qualitativa, que permitam compreender melhor, por um lado, as percep����es, expectativas e necessidades dos pacientes, por outro, as estrat��gias de comunica����o que dever��o ser adoptadas pelo m��dico, atendendo �� complexidade do problema e ao tempo dispon��vel na consulta, tendo em vista aumentar a literacia dos pacientes para uma melhor autogest��o da sua sa��de. Parece ter ficado igualmente patente a grande car��ncia formativa neste dom��nio. A adop����o do modelo biom��dico como paradigma da forma����o m��dica pr�� e p��s-graduada, proposto, h�� precisamente cem anos, por Flexner, tem contribu��do para a desvaloriza����o das componentes psicoemocionais e sociais dos fen��menos de sa��de e de doen��a, assim como para criar clivagens entre cuidados curativos e preventivos e entre medicina geral e familiar e sa��de p��blica. Por��m, o actual padr��o de sa��de/doen��a pr��prio das sociedades desenvolvidas, caracterizado por ���pandemias��� de doen��as cr��nicas e incapacitantes, determinadas por factores de natureza sociocultural e comportamental, ir�� obrigar certamente �� revis��o daquele paradigma e �� necessidade de se (re)adoptarem os grandes princ��pios Hipocr��ticos de compreens��o dos processos de sa��de/doen��a e do papel da medicina.

Cognitive functioning and efficacy of cognitive intervention in Multiple Sclerosis

Tese de Doutoramento em Psicologia Cl��nica / Psicologia

Expectations, Learning and Monetary Policy: An Overview of Recent Research

Expectations about the future are central for determination of current macroeconomic outcomes and the formulation of monetary policy. Recent literature has explored ways for supplementing the benchmark of rational expectations with explicit models of expectations formation that rely on econometric learning. Some apparently natural policy rules turn out to imply expectational instability of private agents��� learning. We use the standard New Keynesian model to illustrate this problem and survey the key results about interest-rate rules that deliver both uniqueness and stability of equilibrium under econometric learning. We then consider some practical concerns such as measurement errors in private expectations, observability of variables and learning of structural parameters required for policy. We also discuss some recent applications including policy design under perpetual learning, estimated models with learning, recurrent hyperinflations, and macroeconomic policy to combat liquidity traps and deflation.

The Dynamics of UK and US Inflation Expectations

This paper investigates the relationship between short term and long term in ation expectations in the US and the UK with a focus on iflation pass through (i.e. how changes in short term expectations affect long term expectations). An econometric methodology is used which allows us to uncover the relationship between in ation pass through and various explanatory variables. We relate our empirical results to theoretical models of anchored, contained and unmoored inflation expectations. For neither country do we find anchored or unmoored inflation expectations. For the US, contained inflation expectations are found. For the UK, our ndings are not consistent with the specifi =c model of contained inflation expectations presented here, but are consistent with a more broad view of expectations being constrained by the existence of an inflation target.