Essa dissertação investiga a existência de um canal de custos de política monetária. Para tanto, utiliza métodos econométricos e de simulação. No primeiro caso, três métodos diferentes são utilizados para a estimação com dados brasileiros de quatro especificações, sendo três delas além das estimadas na literatura. Os resultados obtidos indicam a presença do canal de custos quando essas outras especificações são consideradas. Logo, a literatura empírica existente pode ter subestimado a importância do canal de custo da transmissão monetária. Além disso, foi adaptado e simulado um modelo stock-flow, estudando-se seu comportamento quando são impostas mudanças exógenas nos juros. Neste exercício também foi ilustrada a possibilidade de operação do canal de custos. / This dissertation investigates the existence of a cost-push channel of monetary policy. For this aim, it uses econometric and simulation methods. In the first case, three different methods are used for the estimation using Brazilian data of four specifications, three of them being unusual in the literature. The obtained results reveal the presence of the cost-push channel when these other specifications are considered. Hence the existing empirical literature may have underestimated the relevance of the cost-push channel of monetary transmission. Also, a stock-flow model was adapted and simulated, where we looked into its behavior when exogenous changes on the interest rate are imposed. In this exercise the possibility of the operation of the cost-push channel was also present.

O presente trabalho encontra evidências do papel das principais variáveis macroeconômicas e da liberdade sobre a felicidade dos indivíduos. Usando micro-dados de surveys de bem-estar subjetivo para mais de cem mil pessoas de 74 países, estimamos um modelo de Probit Ordenado. Baseados numa especificação microeconométrica de bem-estar padrão na literatura, controlando por efeitos regionais, tempo e características individuais, o PIB per capita apresenta efeitos positivos e decrescentes sobre o bem-estar reportado, sendo que ganhos de bem-estar proveniente do crescimento econômico parece desaparecer com o tempo, sugerindo uma forte adaptação das pessoas. Os custos das recessões parecem ser maiores do que a simples queda do PIB e o aumento do desemprego. Estimamos que um aumento na taxa de desemprego traz custos psíquicos equivalentes a US$450 para o cidadão médio. Estas evidências estabelecem a noção de que o desemprego tem efeitos negativos sobre o bem-estar mesmo daqueles que continuam empregados. Para os que realmente perdem o emprego, o custo das recessões é de cerca de US$11.400. A inflação parece ter um custo de US$88, na média, o que resulta numa taxa marginal de substituição entre desemprego e inflação de 5, corroborando a existência de uma Função de Bem-Estar Social. Além disso, os custos da inflação recaem especialmente sobre os pobres, culminando em US$364 para os indivíduos do decil de renda mais baixo, sugerindo a natureza regressiva do imposto inflacionário. Encontramos evidências também de que as pessoas parecem derivar utilidade das condições e processos que levam aos resultados econômicos, além da utilidade derivada propriamente dos resultados. Chamamos este tipo de utilidade de utilidade processual. As pessoas preferem viver em ambientes políticos e econômicos mais livres, onde elas tenham mais possibilidades de escolha. A principal consequência teórica deste tipo de evidência é que o fato das pessoas se importarem com processos de escolha viola o axioma fundamental da monotonicidade, de forma que a avaliação do comportamento individual a partir de uma perspectiva tradicional levaria necessariamente a uma representação inconsistente das preferências. A utilidade processual é incompatível com a teoria da utilidade esperada. / This dissertation brings evidence on the role of the main macroeconomic variables and freedom on individual happiness. Using microdata from subjective wellbeing surveys from 74 countries, we estimate an Ordered Probit Model. Based on a standard microeconometric specification, we show that macroeconomics influences wellbeing directly. Even after controlling for time, individual characteristics and regional effects, per capita GDP has positive and diminishing effects on reported wellbeing. Most of this effect vanishes with time, suggesting a strong presence of human adaptation. The costs of recessions are found to be larger than what would be predicted by standard economic theory. We estimate that a rise on the unemployment rate brings psychic losses over and beyond the fall on GDP. They are equivalent to US$450 for the average citizen and US$11,400 to the people who lose their jobs. The cost of inflation, on average is US$88, which results on a marginal substitution rate between unemployment and inflation of around 5. That corroborates the existence of a Social Welfare Fuction. Moreover, we find that the costs of inflation fall specially on the poor, culminating on US$364 for the individuals belonging to the lowest income decile, suggesting a regressive nature of the inflation tax. We also find evidence that people derive utility from the conditions and processes that lead to economic outcomes, beyond the utility derived directly from these outcomes. This kind of utility is called procedural utility. People prefer to live in freer political and economic environments, where they have more possibilities to choose from. The main theoretical consequence of this kind of evidence is that the fact that people care about processes violates the fundamental axiom of monotonicity, which leads the evaluation of individual behavior of standard economic theory necessarily to an inconsistent representation of preferences. Procedural utility is not compatible with the expected utility theory.

A cosmologia inflacionária descreve uma fase durante a qual o nosso universo passou por expansão acelerada em um curto período de tempo a escalas de altas energias. A inflação soluciona os problemas deixados pelo modelo cosmológico da Grande Explosão, tais como os problemas de planura e do horizonte. Nesta fase, o nosso universo era governado por um potencial V(Ø) gerado por um campo escalar inflaton, Ø(t). este potencial deve obedecer às condições de rolagem lenta dadas por {, |n|} 1, onde e n são os parâmetros de rolagem lenta. A cosmologia de branas inspira-se na teoria de cordas descrevendo modelos cosmológicos com dimensões extras. Sua grande ascensão aconteceu com a publicação de dois trabalhos de Randall e Sundrum na década de 90. Estes dois modelos consideram um espaço-tempo AdS5 no qual está inserido uma hipersuperfície 3-dimensional chamada 3-brana (nosso universo). As partículas e forças do modelo padrão estão confinadas nesta 3-brana enquanto o gráviton pode viajar por todo o espaço-tempo. O modelo RS-I considera duas 3-branas que delimitam a dimensão extra enquanto o modelo RS-II considera uma única 3-brana e o tamanho da dimensão extra é infinito. O objetivo deste trabalho é unir estas duas cosmologias de modo que possamos estudar inflação em modelos de branas. Escolhemos a cosmlogia de branas do tipo RS-I para exempleficarmos três potenciais condidatos a gerarem inflação em nosso universo. Para a aceitação de um modelo inflacionário representado por V (Ø), devemos calcular o índice espectral n(k) e sua derivada em relação ao número de onda k, dn(k)/dlnk, deste potencial, e comparar estes resultados teóricos com os dados experimentais do WMAP. É isto que faremos com estes três potenciais / An inflationary cosmology describles a phase in which ou Universe goes through accelerated expansion in a short time period at high energy scales. Inflation solves problems left by the Standard Big Bang cosmological model such as problems of flatness and horizon. In this phase, our Universe is ruled by a potential V(Ø) generated bya an inflaton scalar field Ø(t). This potential generated must obey conditions of slow roll given by {, |n|}1, and n are the parameters of slow roll. A brane cosmology was inspired by a string describing cosmological models with extra dimensions. An interest to it highly arose with a publication of two papers by Randall and Sundrum in the 90s. These two models consider a space-time AdS5 in which the hipersurface with three spacial dimensions is inserted. This hypersurface (our Universe) is called a 3-brane. Particles and forces of the standard model are inserted in this 3-brane whereas the graviton can move through all space-time. In the RS-I model one considers two three-brane which delimit an extra dimension whereas in the RS-II model one consideres a unique 3-brane ande the size of the extra dimension is infinite. The aim of this ork is to unify these two cosmologies in a way which would allow studying inflation in brane models. We choose a cosmology in RS-I branes to exemplify three candidate potentials to generate inflation in our Universe. In order to accept an inflationary model represented by V (Ø), we shold calculate the spectral index n(k)/d/lnk, for this potential, and compare these theoretical results with the available experimental data fo WMAP. These studies will be carried out for the three potentials above mentioned.

The relationship between human cytomegalovirus (HCMV) infections and accelerated immune senescence is controversial. Whereas some studies reported a CMV-associated impaired capacity to control heterologous infections at old age, other studies could not confirm this. We hypothesized that these discrepancies might relate to the variability in the infectious dose of CMV occurring in real life. Here, we investigated the influence of persistent CMV infection on immune perturbations and specifically addressed the role of the infectious dose on the contribution of CMV to accelerated immune senescence. We show in experimental mouse models that the degree of mouse CMV (MCMV)-specific memory CD8(+) T cell accumulation and the phenotypic T cell profile are directly influenced by the infectious dose, and data on HCMV-specific T cells indicate a similar connection. Detailed cluster analysis of the memory CD8(+) T cell development showed that high-dose infection causes a differentiation pathway that progresses faster throughout the life span of the host, suggesting a virus-host balance that is influenced by aging and infectious dose. Importantly, short-term MCMV infection in adult mice is not disadvantageous for heterologous superinfection with lymphocytic choriomeningitis virus (LCMV). However, following long-term CMV infection the strength of the CD8(+) T cell immunity to LCMV superinfection was affected by the initial CMV infectious dose, wherein a high infectious dose was found to be a prerequisite for impaired heterologous immunity. Altogether our results underscore the importance of stratification based on the size and differentiation of the CMV-specific memory T cell pools for the impact on immune senescence, and indicate that reduction of the latent/lytic viral load can be beneficial to diminish CMV-associated immune senescence.

Detection of 'anomalies', empirical regularities that are inexplicable within a preeminent or accepted paradigm, is a key aspect of the operation of scientific endeavour. The dominant theories of financial economics, those deriving from the CAPM/APT literature, hold that there should not exist persistent differences in the returns to assets across calendar frequencies. An extensive review of the literature reveals that in a wide variety of assets and markets there is evidence that returns differ according to the calendar frequency, in particular across days of the week and months of the year and around recurrent holidays. However, this review also reveals considerable room for increased methodological and statistical sophistication. In particular, the nature and extent of the data indicate that techniques based on robust regression, non-parametric statistics and Bayesian inference are more appropriate than the predominantly OLS based approaches displayed in the literature. Papers that adopt these more sophisticated approaches generally find much weaker evidence for such calendar anomalies. In essence, the Irish Stock Exchange operated free from exchange controls and in a broadly homogenous monetary and economic environment from 1988 to 1998. Daily returns from 1988 to 1998, on official equity indices, and from 1993 to 1998 on equal and value weighted equity indices, are examined. The evidence is that even when more sophisticated and appropriate techniques are used there is still some evidence for a daily pattern in the returns to these indices. However this pattern is dissimilar to that found elsewhere, consisting of a midweek positive peak as opposed to the more commonly found low returns at the start of the week and higher returns on Friday. This pattern is not a function of the settlement system, does not appear to be related to the pattern of either microeconomic (firm-specific) or macroeconomic information releases, nor does it appear to be a function of endogenous news generation. Previous international research indicates a January peak in returns, while previous research on the Irish market had also found an April peak. While the investigation here of the monthly pattern of returns confirms, in a statistically and methodologically robust manner, the January peak no evidence is found of an April peak. Examination of the return pattern around exchange holidays indicates that, in common with other markets referenced in the literature, there is a rise in returns before a holiday. However, on decomposition into local and international components we find that although the local effect is strong this effect is negative, which is a major point of departure from previous research findings.

Les difficultés rencontrées par la banque centrale du Vietnam dans la dernière décennie, qui se sont traduites par des écarts importants par rapport à l'objectif d'inflation, nourrissent le débat sur l'adéquation subsistante de l'actuelle stratégie de politique monétaire en place dans le pays depuis 1992. Partant de cette idée, cette thèse a pour objectif d'examiner la pertinence du ciblage monétaire quantitatif. De plus, celle-ci recommande quelques aménagements pour améliorer l'efficacité de la politique monétaire. Après un chapitre introductif, le chapitre 2 propose un état des lieux de l'économie du Vietnam. Les deux chapitres suivants enquêtent sur la satisfaction des exigences imposées dans le cadre du ciblage monétaire, à savoir l'existence d'une fonction stable de demande de monnaie à long terme (traitée dans le chapitre 3) et celle d'un pouvoir prédictif significatif sur l'inflation que possède la monnaie (testée dans le chapitre 4). Il s'avère que la fonction de demande de monnaie est stable, et que l'hypothèse selon laquelle l'évolution des agrégats monétaires a un pouvoir prédictif sur l'inflation n'est pas rejetée. Le ciblage monétaire se trouve ainsi toujours approprié pour le pays. Les deux derniers chapitres calculent et suggèrent les indicateurs de politique monétaire à travers des évaluations exhaustives. Il s'agit des mesures de l'inflation structurelle et d'un indice synthétique des conditions financières, qui se révèlent utile pour la prise de décision de la banque centrale. / Difficulties of the central bank of Vietnam during the last decade in controlling price inflation and securing its inflation goals have launched and nurtured a vigorous debate on whether the current monetary policy strategy, in place since 1992 remains always appropriate. lnspired of this idea, this thesis aims to examine the relevance of the quantitative monetary targeting framework. Furthermore, the thesis recommends some arrangement in order to improve monetary policy efficiency. After an introductory chapter, Chapter 2 propose the state of the art of the economy of Vietnam. Two following chapters investigate the conditions that an effective money targeting strategy requires and whether they are fully satisfied in Vietnam. Indeed, the existence of a stable money demand function in the long run is considered in Chapter 3, and a significant predictive power that money should have on inflation is tested in Chapter 4. It is proved that the money demand function is stable and the hypothesis according to which money growth may forecast future inflation cannot be rejected. The monetary targeting is therefore still relevant for Vietnam. The last two chapters compute and suggest various monetary policy indicators by means of exhaustive evaluation exercises. Different core inflation measure and a composite index of financial conditions are introduced, which are justified to be meaningful for the policy making process of the central bank.

Inflationary cosmology is the leading candidate for explaining the homogeneity, isotropy and spatial flatness of the universe whilst also providing the mechanism for the seeding of large scale structure. The central theme of inflationary dynamics involves the evolution of a scalar field, called the inflaton, such that its potential drives an accelerated expansion. Warm inflation is the dynamical realization in which interactions between the inflaton and other fields can lead to dissipation of inflaton energy to other dynamical degrees of freedom. Heavy fields coupled to the inflaton mediate the transfer of inflaton energy to light degrees of freedom which thermalize and heat the universe. This damps the inflaton’s motion and allows for the potential formation of a thermal bath during the inflationary period. Hybrid inflation models are a natural way in which warm inflation can be realized, with dissipation of inflaton energy mediated by the waterfall fields to fields in the light sector. In this thesis I outline the dynamics and observational predictions of supersymmetric hybrid inflation driven by radiative corrections in the warm regime. As in the standard cold inflationary scenario inflation ends when the effective mass squared of the waterfall field becomes negative, with the tachyonic instability driving the system to a global minimum in a process called the waterfall transition. I present the effect of including thermal mass corrections to the waterfall fields, and SUSY mass splittings on the quantum effective potential and the resulting dissipation coefficient. I show that including dissipative effects can significantly prolong the inflationary period to produce 50-60 e-folds of inflation with an observationally consistent primordial spectrum. Inflation still requires a microphysical description within a fundamental theory of quantum gravity. This has prompted the search for inflaton candidates within the superabundance of scalar fields present in string theory compactifications, with brane-antibrane inflation in particular emerging as a concrete implementation of SUSY hybrid inflation in a UV complete particle physics model. Inflation proceeds in a brane-antibrane system through the movement of a stack of branes towards a stack of antibranes, with the inflaton field being the interbrane distance. Warm inflation can be implemented in a brane-antibrane system with dissipation of inflaton energy mediated by fields corresponding to strings stretched between the brane and antibrane stacks. It has been shown that this dissipation of inflaton energy in warm inflation can greatly alleviate the η-problem in brane-antibrane scenarios. Whilst these strings mediating dissipation have end points fixed on to both the D3 and D3 stacks, the compact nature of the geometry within which the system is constructed allows these strings to have different winding modes. We investigated how strings with increasing winding number can provide an enhancement to the dissipation coefficient, allowing a significant reduction in the number of branes and antibranes in the warm inflation system, whilst also modifying the inflationary dynamics by reducing the speed at which the system evolves. This may go some way to alleviating the η-problem associated with some constructions of brane-antibrane inflation whilst also potentially providing the best way to motivate the large field multiplicities associated with warm inflation models.

Under senare år har såväl forskare som centralbanker observerat att sambandet mellan inflation och arbetslöshet förfaller försvagat. Två uppmärksammade förklaringar till det försvagade sambandet är att inflationsförväntningar blivit förankrade vid centralbankers inflationsmål samt att korttidsarbetslöshet har en större betydelse för lönebildning än total arbetslöshet. Ball och Mazumder (2014) kombinerar dessa förklaringar och finner att en Phillipskurva med förankrade inflationsförväntningar och korttidsarbetslöshet bättre förklarar inflationen i amerikansk ekonomi än en traditionell Phillipskurva mellan 2000K1-2014K3. På basis av data för viktad medianinflation från Riksbanken och arbetslöshet från Statistiska centralbyrån visar denna studie att Ball och Mazumders (2014) resultat inte kan replikeras på svensk ekonomi. Resultatet indikerar att inflationsförväntningarna i Sverige inte är helt förankrade samtidigt som gruppen korttidsarbetslösa endast har en marginellt större betydelse än total arbetslöshet för inflationen. Detta kan tänkas bero på att förtroendet för Riksbankens inflationsmål minskat och på att arbetsmarknadspolitiska åtgärder gör att även gruppen långtidsarbetslösa har betydelse för lönebildningen i Sverige.

The aim of this thesis is to verify the existence of dependence between inflation and unemployment through the Phillips curve in the Czech Republic and its neighboring countries (Poland, Austria, Slovakia and Germany). This observed relationship is complemented by the economic development of both macroeconomic variables in these countries. The first chapter is devoted to the theoretical background of inflation, unemployment and Phillips curves. In the second chapter, the data used to verify the existence of the inverse relationship between inflation and unemployment is defined. The third chapter is country-by-country, with the development of inflation and unemployment rates first and then Phillips curves based on available data. The last section is devoted to a summary of the achieved results.

The aim of the thesis is to address issues concerning modelling and evaluation of monetary policy by obtaining targeting rules from optimisation techniques using welfare loss functions that capture asymmetries and zone targeting behaviours. The motivation is that the specification of the most widely used monetary policy rule, i.e. the Taylor rule, may not adequately capture the stylised key features of monetary policy practice as has been shown by Nobay and Peel (2003), Aksoy et al. (2006) and Boinet and Martin (2008). The thesis also addresses the importance of the behaviour of certain financial asset prices and their implications in monetary policy decision making. It also analyses the impact of uncertainty about the true state of the economy on domestic interest rates. First, the response of monetary policy to deviations of inflation and output from their target values based on a framework that allows asymmetric and zone targeting monetary authorities’ preferences is estimated.1 Second, the monetary policy reaction function, which is augmented with a comprehensive index that collects and synthesises information from the financial asset markets is estimated for South Africa based on a framework that allows asymmetric and zone targeting monetary authorities’ preferences.2 Third, the impact of uncertainty about the state of the economy on monetary policy in South Africa using a framework that allows asymmetric and zone targeting monetary authorities’ preferences is analysed. The main findings are that the monetary authorities’ response towards inflation is zone symmetric and their response to output fluctuations is asymmetric. The second major finding is that the conditions in the financial asset markets form an important information set for the monetary authorities and that the monetary authorities pay close attention to the conditions in these markets by placing an equal weight on financial asset markets booms and recessions. The empirical results also reveal a significant impact of uncertainty about the state of the economy on domestic interest rates during the inflation targeting period and that the monetary authorities exhibit discretionary behaviour when implementing monetary policy under uncertainty. The thesis contributes to the body of knowledge in the field of economics by addressing important issues in monetary policy design and conduct using a framework that capture the stylised key features of monetary policy practice. All these issues are important in design and conduct of monetary policy. They are currently debated at many central banks including South Africa. / Thesis (PhD)--University of Pretoria, 2011. / Economics / unrestricted