This thesis is concerned with macroeconomic dynamics under various forms of uncertainty. Chapter 2 recognizes that the information flow from the interest rate is impeded when the nominal interest rate hits the zero lower bound. This impediment can (a) increase the duration of zero lower bound episodes and (b) bring about more persistent deflationary pressure. Moreover, it can make the exit from the zero lower bound disorderly. Chapters 3 and 4 are concerned with dynamics of aggregate variables under Knightian Uncertainty. To overcome difficulties with expectations formation under Knightian Uncertainty, the agents follow Interactive Trial and Error Learning (ITEL) (Young, 2009; Pradelski and Young, 2012) to choose investment portfolios. This involves learning by occasionally experimenting with new actions even when the current action proves to be good. Two applications of ITEL are presented. Chapter 3 deals with the growth of aggregate variables. The growth model can match several business cycle features of the US real aggregate wealth data. Chapter 4 considers a portfolio choice problem. The portfolio choice model can match the first two moments of the US real excess return of equity over bonds almost perfectly. Chapter 5 explores “This Time Is Different Syndrome” of Reinhart and Rogoff (2009) in a setting where the agents are learning under Knightian Uncertainty. The agents are grouped into different generations and their models compete in terms of forecasting power. The predecessor’s model is discarded together with the data set when its forecasting power is worse than the current generation’s model. This loss of relevant data is rooted in focusing only on forecasting well in the short-run. By shifting the weight towards finding the true model of the economy, this problem can be substantially reduced.

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This thesis proposes a new econometric methodology for the estimation and inference of macro- economic models in the presence of time variation in the parameters. A novel quasi-Bayesian local likelihood (QBLL) approach is established and it is shown that the method gives rise to as- ymptotically valid quasi-posterior distributions. In addition, in the special case of linear Gaussian models, expressions of the quasi-posteriors are derived in closed form, which simpli es inference and makes the use of MCMC unnecessary. Inference based on the QBLL approach, as a consequence of modelling parameter variation nonparametrically, is robust to di¤erent processes for the drifting parameters, as its validity does not depend on parametric restrictions typically imposed by alterna- tive state space models. In addition, the Bayesian treatment of the approach provides a remedy to the curse of dimensionality by accommodating large dimensional systems. We demonstrate that the proposed estimators exhibit good nite sample properties, and, unlike the alternative para- metric state space models, are robust to di¤erent parameter processes. We provide a variety of interesting macroeconomic applications and forecasting exercises to reduced-form VAR models. In addition, we develop the methodology to the estimation of structural DSGE models in the presence of parameter drift. We apply the proposed algorithms to di¤erent medium-sized DSGE models in order to study structural change in the parameters.

The purpose of this paper is to present an alternative perspective of marketing, which is lookingat the concept from a macro point of view, with a chosen country-Vietnam. There are three maingoals that this investigation strives to achieve. In specific, it aims first to observe whether theVietnamese consumers have favorable or unfavorable attitudes towards the marketing systemthat currently operating nationally. This is reached through an application of ICSM model, whichbased very much on the famous marketing mix paradigm (4Ps).The second purpose of this thesis is to test whether Vietnam market exist the relationshipsbetween consumers’ sentiment toward marketing practices and customer satisfaction. Theapplied models in this case are Kano Model and ACSI model where it proposed that therelationship exits. Thirdly, as Vietnam is a developing country, the role of government isexpected to have an effect on the issue of marketing practice, which implicitly can influence thevariables of consumer attitude and consumer satisfaction. Therefore, we took this opportunity todetermine whether it is the case and reflects that with results from previous studies.And above all, demographic factors including age, gender, education background, andoccupation are tested against the three main variables of attitude, satisfaction, and government.To achieve all the three main goals, we adopt quantitative research strategy with self-completedquestionnaires. A total sample of 445 respondents is obtained from two biggest cities ofVietnam- Hanoi and Ho Chi Minh City. The analyzed results show that Vietnamese consumersare much more favorable to the current marketing activities, in comparison to other countrieswith well-developed economic situation. Moreover, the results also proved that there is positiverelationship between the two pairs of variable: attitude - satisfaction, and government regulations- satisfaction; while between government and attitude, a negative correlation is found. Finally,the statistics also shows that demographic factors do have correlation on the variables thoughsome are more influential than others.

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In this study macro-invertebrates were sampled quantitatively in 10 lowland vegetation communities on Marion Island over a one-year period commencing in May 1996 as part of a larger investigation into the distribution, abundance and species energy use of invertebrates across an altitudinal transect on Marion Island. The data collected for this particular study were used to investigate the habitat specificity and seasonality of the macro-invertebrates, as well as the impact of alien species on the local community. As part of the latter study a watching brief for alien species was kept throughout the field year and the alien species list was updated accordingly. The quantitative data were also used to compare changes in the density and biomass of selected macro-invertebrate species between 1976/77 and 1996/97 by reworking the data on macro-invertebrates collected by Alan Burger in 1976/77 during the course of his work on the Lesser Sheathbill. In the current study it was found that the majority of the macro-invertebrate species are not particularly habitat specific. Rather, they generally prefer either moist mire habitats, or the more well-drained non-mire vegetation complexes. In addition, many of the species had pronounced peaks in abundance in a given season (winter, summer, autumn and spring peaks were recorded), although this seasonality varied between species and between habitats for a given species. Although this finding does not support previous generalizations concerning an absence of seasonality in sub-Antarctic invertebrates, it does show that sub-Antarctic invertebrates, like their Antarctic counterparts, may have extremely flexible life history strategies. Limnophyes minimus was found to be one of the most abundant alien species on the island, and reached high densities in most of the plant communities sampled, with the highest density being recorded in the Cotula plumosa biotically influenced community (annual mean of 4365 individuals.m-2 ) and the lowest in the Crassula moschata salt spray community (annual mean of 41 individuals.m-2 ). Estimates of litter ingestion indicated that L. minimus larvae are capable of consuming between 0.07 and 8.54 g(dry mass)·m-2 per year, depending on the community. In some communities this litter consumption amounted to an order of magnitude more than that consumed by Pringleophaga marioni (Lepidoptera, Tineidae). Although the larvae of this moth species are thought to represent the bottleneck to nutrient recycling on the island, this study showed that midge larvae may also contribute substantially to this process. As a consequence, the considerable changes that have been predicted to occur in Marion Island's terrestrial ecosystem as a consequence of enhanced predation by mice on P. marioni larvae, may be retarded or obscured by the contribution of the midge larvae to nutrient cycling. Hence, it is suggested that greater attention be given to the small and inconspicuous elements of the alien sub-Antarctic faunas because such species may have profound consequences for ecosystem functioning on these islands. The likely impact of alien species on the terrestrial macro-invertebrates, and the communities they belong to, was further highlighted by the dramatic decline in the biomasses of the macro-invertebrates between 1976/77 and 1996/97. Significant declines in biomass of between 83-97% were found for Lepidoptera larvae (mostly Pringleophaga marioni) and for weevils, the major prey species of the introduced house mouse between 1976/77 and 1996/97, although non-prey species appear to have shown either no changes (the indigenous snail Notodicus hookeri) or increases in abundance (the introduced slug Deroceras caruanae). However, differences in sampling strategies adopted by these two studies and others investigating macro-invertebrate abundances mean that the current results may well be underestimates of change, while other studies must be interpreted with considerable caution. Nonetheless, the current findings and those of authors suggest that mice may be having pronounced impacts on the terrestrial ecosystem at Marion Island. In sum, the findings of this thesis indicate that considerably more attention must be given to well-planned collaborative work to address critically important management questions, identified by the Prince Edward Island Management Committee, and that considerable care must be taken to prevent the further introduction of alien species to sub-Antarctic islands. Copyright / Dissertation (MSc)--University of Pretoria, 2010. / Zoology and Entomology / unrestricted

The subject of this work is to describe the steps of the process of implementation of macro prudential policy which have been made up to now and to assess the efficiency of the policy. The work offers the reader a comprehensive view of the topic. The work is divided into three parts. The first part deals with overall characteristic of macro prudential policy. The second part describes the macro prudential tools. In the last part, the efficiency of macro prudential policy and its tools is evaluated. The aim of this work is to provide the reader with a through view on macro prudential policy and to highlight the problematic parts of the implementation of the policy. Furthermore, it aims to describe the efficiency and effectiveness of the policy and its tools.

This thesis presents three dynamic stochastic general equilibrium models to answer three macroeconomic questions. In each model, I impose one or more frictions or constraints and analyse how these frictions affect macroeconomic dynamics. Chapter 2 studies the coordination of fiscal and monetary policies under optimal commitment and discretion policies under a New Keynesian framework. The chapter shows that when there is indexation in price setting which depends on the lagged output gap as in Steinsson (2003), under the optimal commitment policy, both fiscal and monetary policies have active roles in inflation stabilisation, even although debt follows a unit-root process. Under the optimal discretion policy, both fiscal and monetary policies have active roles in inflation stabilisation to drive debt back to the pre-shock level, consistent with Leith and Wren-Lewis (2008). Extending the model to include capital accumulation does not alter these results. Chapter 3 presents a microfounded two-country model of global imbalances and debt deleveraging. During global imbalances a sustained rise in saving in one country can lead to a worldwide fall in the interest rates and an accumulation of debt in the other country. When an ensuing deleveraging shock occurs as a result of the global financial crisis, the interest rates are forced further down. I show that in the presence of a liquidity trap the deleveraging country may face a combination of a large fall in output, deflation and real exchange rate appreciation, as a result of debt deflation. Chapter 4 adds a highly-leveraged financial sector to the Ramsey model and shows that this augments the macroeconomic effects of aggregate productivity shocks. My model is built on the financial-accelerator approach of Bernanke, Gertler and Gilchrist (BGG), in which leveraged goods-producers borrow from a competitive financial sector. In this chapter, by contrast, financial institutions are leveraged and subject to idiosyncratic productivity shocks. They obtain funds by paying an interest rate above the risk free rate, and this risk premium is anti-cyclical, and so amplifies the shocks. My parameterisation, based on US data, is one in which the leverage of the financial sector is two and a half times that of the goods-producers in the BGG model. This causes a much more significant augmentation of aggregate productivity shocks than that found in the BGG model.

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Ce travail porte sur les relations entre les propositions du texte et les macro-propositions telles qu’elles ont été définies par van Dijk et Kintsch. L’étude a été conduite sur un corpus de textes issus d’une émission radiophonique interactive. Une première partie du travail a été consacrée à la recherche d’un lien entre l’organisation informationnelle des propositions et l’organisation séquentielle du texte. Les liens décrits par Fries et Martin à propos de textes écrits n’ont pas été retrouvés dans les textes oraux du corpus. Dans une seconde partie nous avons étudié la formation de macro-propositions par généralisation. Une analyse des lexicalisations des macro-propositions a montré que la généralisation se faisait sur une base conceptuelle et non lexicale et que les macro-règles décrites par van Dijk et Kintsch ne rendaient pas compte de la formation de la totalité des macro-propositions générées lors de la compréhension. / This study examines the relations between textual propositions and macro-propositions as defined by van Dijk and Kintsch. The corpus used consisted of texts taken from a BBC phone in programme. In the first part of the study a link was sought between the structure of the text and the information structure of the messages. The patterns identified by Fries and Martin in written texts however could not be found in the oral texts of the corpus. The second part of the research focused on macro-propositions deriving from generalisation. An analysis of the lexicalisation of the concepts of these macro-propositions showed that generalisation was made on a conceptual basis as opposed to a lexical one and that the generalisation macro-rule defined by van Dijk and Kintsch fails to account for all the macro-propositions generated during comprehension.