This study was motivated by the desire to contribute to the understanding of the movement of house prices and the role of the so-called economic ‘fundamentals’ in the housing market, especially within an Australian context. The core objective of this thesis is to aid understanding of the economic and other mechanisms by which the Australian housing market operates. We do this by constructing an analytical framework, or model, that encompasses the most important characteristics of the housing market. This thesis examines two important aspects of the Australian housing market: movements of house prices and changes in the net capital stock of dwellings in Australia. Movements of house prices are modelled from two perspectives: firstly, using the ‘fundamental’ approach, which explains the phenomena by changes in such ‘fundamental’ explanatory variables as income, interest rates, population and prices of building materials, and secondly, by analysing spatial interdependence of house prices in Australian capital cities. Changes in stock of dwellings were also modelled on the basis of a ‘fundamental’ approach by states and for Australia as a whole...

The main objective of this research paper is to find the association between unemployment rate and GDP growth which is presented empirically by Arthur Okun’s in early 1960s. For this purpose I have used annual time series data during the period 1981-2005 of Pakistan. I applied difference version of Okun’s law which is more appropriate to access results directly from empirical data. In order to find long run relation between the variables I used Engle-Granger cointegration technique and Error Correction Mechanism (ECM) to find the short term behavior of GDP growth to its long run value. This paper verifies negative relationship between unemployment rate and GDP growth and both variables have long run relation with each other. Moreover GDP growth will adjust more quickly towards equilibrium in the long run.

Submitted by Mariana Dornelles Vargas (marianadv) on 2015-03-19T15:37:37Z No. of bitstreams: 1 analise_importacao.pdf: 945712 bytes, checksum: 6101bf28275e0f55c9b783cb13f2a508 (MD5) / Made available in DSpace on 2015-03-19T15:37:37Z (GMT). No. of bitstreams: 1 analise_importacao.pdf: 945712 bytes, checksum: 6101bf28275e0f55c9b783cb13f2a508 (MD5) Previous issue date: 2011-03-30 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O presente trabalho procurou avaliar o comportamento da função de demanda brasileira por arroz pós-Mercosul e sua relação com a variação na renda, nos preços internos e externos, na indústria e política comercial brasileira. Para a análise, foi desenvolvido um modelo teórico, o qual fundamentou a especificação dos modelos econométricos para o arroz em casca e beneficiado. Considerou-se na investigação estatística dados históricos de janeiro de 1995 a junho de 2010, tendo como objetivo geral testar a adequação de modelos lineares e não-lineares que representem as relações de curto e longo prazo das variáveis de comércio exterior brasileiro do setor. Além disso, pretende-se datar a cronologia dos ciclos das importações de arroz e verificar a relação desses com as idiossincrasias da condução das políticas econômicas, bem como com eventos climáticos. As elasticidades encontradas apresentaram sinais coerentes com o modelo econômico definido em sua maioria. Os resultados obtidos permitiram interpretar a dinâmica do mercado importador de arroz no Brasil. Em geral, os impactos de longo prazo da renda e preço doméstico foram os principais determinantes das importações e ressalta-se o comportamento de bem inferior de ambos os tipos de arroz nas equações trimestrais. Já o preço de importação contribui menos que proporcionalmente, ao passo que o importador parece ajustar a quantidade importada do período com certo grau de defasagem. Já a indústria, tendo como base dados trimestrais, manteve uma relação contra-cíclica com as importações de ambos os tipos de arroz, embora não tenha se mostrado significativa para a maioria dos modelos. A dinâmica de correção do modelo a choques no longo prazo foi atenuada nas estimativas não-lineares mensais, enquanto permaneceu praticamente estável nas estimativas trimestrais. Ainda, conforme os resultados é possível afirmar que os ciclos de expansão das importações de arroz beneficiado durante o período foram, em média, mais longos que as retrações. Finalmente, pode-se entender que os ciclos de importação se mostraram fortemente relacionados a eventos climáticos adversos e à alterações da política comercial. / This study tried to investigate the behavior of Brazilian demand for post-Mercosur rice and its relation with variation in income, in domestic and foreign prices, in industry and in Brazil?s trade policy. For the analysis, a theoretical model was developed, which based the specification of econometric models for rough and milled rice. The statistical investigation considered historical data from January 1995 through June 2010, aiming mainly to test the adequacy of linear and nonlinear relations that represent short and long-term variables of the Brazilian foreign trade in the sector. Furthermore, there is the goal of setting the chronology of the cycles of rice imports and verifying their relationship with idiosyncrasies of the conduct of economic policies, as well as of weather events. The elasticities estimated showed signs consistent with the economic model set in their majority. The results achieved allowed the interpretation of the rice import market dynamics in Brazil. In general, long-term impacts from income and domestic prices were the main determinants of imports; it should be pointed out the much lower behavior of both types of rice in quarterly equations. The price of imports contributes less than proportionately, while the importer seems to adjust the quantity imported in the period with some lag. The industry, based on quarterly data, sustained its counter-cyclical relation with the imports of both types of rice, although it has been not proved significant for most models. The correction dynamic of the model to long-term shocks was eased in monthly non-linear equations, while it remained nearly stable in quarterly estimates. Besides, still according to results, it is possible to say that expansion cycles of imports of milled rice are on average longer than the contractions. Finally, one can understand that import cycles were strongly related to adverse climatic events, as well as to alterations in trade policy.

Submitted by Mariana Dornelles Vargas (marianadv) on 2015-06-15T14:27:47Z No. of bitstreams: 1 efeitos_mecanismos.pdf: 1238336 bytes, checksum: d005a9b54ec8b6cb1f09c6a122961c17 (MD5) / Made available in DSpace on 2015-06-15T14:27:47Z (GMT). No. of bitstreams: 1 efeitos_mecanismos.pdf: 1238336 bytes, checksum: d005a9b54ec8b6cb1f09c6a122961c17 (MD5) Previous issue date: 2012-01-12 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O objetivo desse estudo é investigar de que forma ocorrem os efeitos de transmissão de política monetária no Brasil e no Chile. Para esse fim, é utilizado um modelo econométrico VEC (vector error correction), no período do primeiro trimestre de 1995 até o último de 2010 para o modelo brasileiro de do primeiro trimestre de 2000 até o primeiro de 2011 no Chile. Inicialmente, a revisão teórica e empírica faz uma discussão acerca do tema. Subsequentemente, são analisados alguns fatos estilizados sobre as políticas monetárias do Brasil e do Chile e outras variáveis macroeconômicas. Os principais resultados encontrados por meio do modelo econométrico mostraram que a política monetária brasileira pode ser capaz de influenciar a produção industrial no longo prazo, e ocorre um trade-off entre elevação na atividade econômica e controle da inflação. Adicionalmente, a manutenção da taxa de juros num patamar alto pode implicar em queda da atividade econômica, elevação da dívida pública sobre o PIB e valorização cambial, que possui efeito de controlar a inflação, mas reduz a atividade industrial. Entretanto, a alta nos juros pode ser influenciada por aumentos da dívida pública e no risco. A taxa de câmbio mostrou-se como um canal relevante para a transmissão de política monetária, no entanto, sem efeitos no longo prazo. No Chile, a política monetária pareceu agir passivamente, com a produção industrial sendo o canal mais relevante para a desaceleração da inflação. A taxa de câmbio não demonstrou desempenhar um papel relevante na transmissão da política monetária. Por sua vez, um aumento na taxa de juros pareceu ter maior sensibilidade na queda na atividade industrial em relação à desaceleração da inflação, com efeito de longo prazo. A pouca influência dos riscos na taxa de juros pode indicar que o Banco Central chileno consegue manter essa variável num patamar baixo, otimizando sua atuação. / The aim of this study is to investigate how monetary policies are transmitted and their effects in Brazil and Chile. For this purpose, a VEC (vector error correction) model is applied to data running from the first quarter of 1995 to the fourth quarter of 2010 for Brazil and from the first quarter of 2000 to the first of 2011 in Chilean case. Initially, in the review, a theoretical and empirical discussion of the theme is performed. Subsequently, some stylized facts about the monetary policies of Brazil and Chile and other macroeconomic variables for these countries are analyzed. The main results found by the econometric model are that the Brazilian monetary policy may be able to influence economic activity in the long run, and that is a trade-off between increased industrial production and inflation control. Additionally, keeping interest rates at a high level can result in an economic activity downturn, a rising public debt to GDP ratio and an exchange rate appreciation, which has the effect of controlling inflation, but reduces industrial activity. However, the rise in interest rates may be influenced by increases in public debt and risk. The exchange rate showed up as a relevant channel for the transmission of monetary policy, although, not exhibiting long run effects. In Chile, monetary policy seemed to act passively, with industrial production being the most important channel for the deceleration of inflation. The exchange rate has not demonstrated an important role in monetary policy transmission. Furthermore, an increase in interest rates seemed to have greater sensitivity in the fall in industrial activity in relation to the deceleration of inflation, and a long run effect. The low influence of risks in the interest rate may indicate that the Chilean Central Bank can keep this variable in a low base, optimizing its performance.

Submitted by Nara Lays Domingues Viana Oliveira (naradv) on 2015-08-20T18:22:48Z No. of bitstreams: 1 0000018C.pdf: 697461 bytes, checksum: ea0ba4f605fcf7ea77f86c8134641bdf (MD5) / Made available in DSpace on 2015-08-20T18:22:48Z (GMT). No. of bitstreams: 1 0000018C.pdf: 697461 bytes, checksum: ea0ba4f605fcf7ea77f86c8134641bdf (MD5) Previous issue date: 2012-03-29 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este estudo tem como objetivo mensurar o impacto dos determinantes da oferta de açúcar e álcool no Brasil com o intuito de captar a intensidade e a duração que as oscilações de preços e de produções transmitem para o mercado brasileiro. O período analisado está inserido na fase pós-desregulamentação do setor sucroalcooleiro, no qual os preços passaram a ser determinados de acordo com as regras de livre mercado e o governo, por sua vez, passou a exercer uma função secundária na regulação do setor. Nesse sentido, o modelo econométrico proposto para o presente estudo consiste no método de vetor auto-regressivo com mecanismo de correção de erro (VEC), com base em séries temporais trimestrais compreendidas entre o período de 1995 a 2009. Para uma melhor compreensão das análises, primeiramente apresentou-se, nos primeiros capítulos, uma revisão dos conceitos históricos e teóricos que abordam os principais fatores condicionantes da oferta de açúcar e álcool no Brasil. Posteriormente, analisou-se, atráves dos testes de causalidade de Granger e funções de impulso resposta (FIR), a precedência entre as variáveis compreendidas nos modelos, bem como o impulso que uma variável exerce sobre as demais. Por fim, com base nos testes apresentados, chegou-se à conclusão que o modelo B com quatro defasagens apresentou os resultados mais coerentes e conclusivos em relação ao embasamento teórico e à dinâmica do setor. Dentre os principais resultados, fica evidenciada a relação positiva do açúcar e do álcool em relação à determinação de suas ofertas, no sentido de que o aumento da oferta de um produto gere no mesmo sentido a expansão do outro. Adicionalmente, os comportamentos das variáveis de preços, em parte, apresentaram resultados condizentes com a realidade do setor e na maioria dos impulsos corresponderam com os sinais esperados. As exportações de açúcar e taxa de câmbio impactam positivamente na renda recebida pelo produtor e inferem positivamente para a expansão da oferta brasileira de açúcar. / This study has the objective to measure the impact of the determinants for the supply of sugar and alcohol in Brazil, with the intention to capture the duration of the osclillations of prices and production influences to the Brazilian market. The analyzed period is inserted in the post-deregulation phase of the alcohol –sugar sector, in which the prices started to be determined according to the rules of free market, and the government itself started to play a secondary role in the regulation of the sector. At this point the econometric model proposed for the following study consists of a vector auto-regressive model with an error correction mechanism based on quarterly temporal series within the period of 1995 to 2009. For a better comprehension of the analysis, initially it is introduced in the first chapters a review of historical and theoretical concepts that deal with the main conditioning factors of sugar and alcohol offer in Brazil. Afterwards, it was analyzed through Granger causality tests and the impulse response function (IRF) the precedence among the variables comprehended in the models, as well as the impulse that a variable applies over the others. At last based on the tests presented it has got to the conclusion that the model B with four lags, showed the most coherent and conclusive results concerning the theoretical support and the dynamics of the sector. Among the main results it is evident the positive relationship of sugar and ethanol concerning the determination of its offers, at the sense that the increase one product generates, at the same point, the expansion of the other. In addition the behaviors of the variables of prices, in part presented results in agreement to the expected signals. The sugar exports and exchange rate impact positively in the income received by the producer and infer positively for the expansion of the Brazilian sugar offer.

Liberalisation of trade is deepening, and so have the incentive schemes put in place by a number of countries to promote it. International trade promotion agencies in developing countries are actively promoting their countries as the best, with which to trade. With international trade emerging as a favourite source of revenue and technology transfer for most countries, profound questions about the impact of trade liberalisation to economic growth are addressed in this study. The main purpose of this study is to empirically assess the relationship between trade liberalisation and economic growth in Zimbabwe using annual time series data from 1980 to 2017. Autoregressive distributed lag (ARDL) bounds testing approach to cointegration and Error Correction Mechanism (ECM) are applied in order to investigate the long run and short run impact of trade liberalisation on economic growth. The results proved the existence of a positive long-run relationship between trade liberalisation and economic growth. The study therefore concludes that policy makers and government negotiators in Zimbabwe should introduce policies that promote openness through the removal of barriers to trade and export promotion in order to promote overall growth of the economy. / Economics / M. Com (Economics)

[pt] O objeto desta dissertação é investigar o impacto do câmbio em diversos setores de exportação no Brasil, utilizando equações econométricas uniequacionais. Em particular, é utilizado o modelo em defasagens autoregressivas distribuídas (ADL) para obtenção das elasticidades de longo prazo. A dinâmica de curto prazo é obtida sob a forma de um modelo de correção de erros (ECM). São estimadas seis formas alternativas para a equação das exportações, as quais se diferenciam pelas medidas de câmbio (três) e renda mundial (duas) utilizadas. As estimativas das elasticidades- câmbio das exportações indicam uma relação de longo prazo na maior parte dos 18 setores estudados, porém seu impacto sobre o nível das exportações não é considerado alto, pois as estimativas em sua maioria são inferiores a unidade. No curto prazo, o impacto do câmbio revelou-se ainda mais baixo. Em síntese, o presente estudo mostra que, para o crescimento das exportações, o comportamento do câmbio não é o fator de destaque. No bojo desse estudo, no entanto, outros determinantes das exportações setoriais são identificados: renda mundial, competitividade externa e o produto potencial da indústria. / [en] The aim of this dissertation is to investigate the impact of the exchange rate in several export sectors of the brazilian economy, throughout the use of uniequation econometric models. In particular, we make use of the autoregressive distributed lags model (ADL) to obtain the long run exchange rate elasticities. The short run dynamics is obtained by use of a model with error correction mechanism (ECM). We estimate six alternative forms for the export equations, which differ by the indicators of exchange rate (three) and world income (two) used. The elasticities estimated for the majority of the 18 export sectors investigated suggest the existence of a long run relation between exchange rate and quantum of exports. Nevertheless this impact is not substantial, given the small size of the elasticities coefficients. On the short run, the exchange rate impact was even less pronounced. In a nut shell, our study shows that, in Brazil, the growth of exports is not very much affected by the exchange rate, although other factors have been found to have an effect: world income, foreign competition and industry potential product.

Made available in DSpace on 2015-03-05T18:57:20Z (GMT). No. of bitstreams: 0 Previous issue date: 1 / Nenhuma / Esta dissertação trata da estimação das equações de exportação para o total da economia brasileira e para o setor madeira e mobiliário do Brasil, a partir de dados trimestrais, no período entre 1985 e 2006. Os procedimentos econométricos utilizam o conceito de co-integração de Johansen associado a um modelo de correção de erros. É dada especial atenção a um possível problema de instabilidade dos parâmetros resultante, principalmente, do impacto da abertura comercial no início do período, das mudanças associadas ao Plano Real e da elevação nos preços de exportação no final do período. Um dos aspectos mais interessantes, relacionado com a abertura comercial brasileira, está presente na demanda por exportações onde a renda externa passa a ter uma importância relativa muito maior ao longo do período quando comparada ao câmbio. Esta mudança está presente no âmbito do setor madeira e mobiliário, mas também é destaque no agregado. Outro resultado importante, agora no lado da oferta por exportações, mostra a relação / This dissertation is about the estimation of export equations for both Brazilian total economy and Brazilian wood-furniture sector, using quarterly data, from 1985 to 2006. The econometric procedures use the Johansen’s co-integration concept associated to an error-correction model. Special attention is dedicated to a possible problem of instability in parameters resulting, mainly, from the impact of the opening trade in the beginning of the period, from changes associated to the Real Plan and from the raise of the export prices in the end of the period. One of the most interesting aspects, related to the Brazilian trade opening, occurs in the export demand where the foreign income starts to have relatively higher importance along the period when compared to the exchange rate. This change is present in the ambit of the wood-furniture sector, but it also stands out for the aggregate. Another important result, now related to export supply, shows the relation of significance between the main sources of exporter

Cette recherche a pour but d’évaluer le rôle de la vision et de la proprioception pour la perception et le contrôle de l’orientation spatiale de la main chez l’humain. L’orientation spatiale de la main est une composante importante des mouvements d’atteinte et de saisie. Toutefois, peu d’attention a été portée à l’étude de l’orientation spatiale de la main dans la littérature. À notre connaissance, cette étude est la première à évaluer spécifiquement l’influence des informations sensorielles et de l’expérience visuelle pour la perception et le contrôle en temps réel de l'orientation spatiale de la main pendant le mouvement d’atteinte naturel vers une cible stationnaire. Le premier objectif était d’étudier la contribution de la vision et de la proprioception dans des tâches de perception et de mouvement d’orientation de la main. Dans la tâche de perception (orientation-matching task), les sujets devaient passivement ou activement aligner une poignée de forme rectangulaire avec une cible fixée dans différentes orientations. Les rotations de l’avant-bras et du poignet étaient soit imposées par l’expérimentateur, soit effectuées par les sujets. Dans la tâche de mouvement d’orientation et d’atteinte simultanées (letter posting task 1), les sujets ont réalisé des mouvements d’atteinte et de rotation simultanées de la main afin d’insérer la poignée rectangulaire dans une fente fixée dans les mêmes orientations. Les tâches ont été réalisées dans différentes conditions sensorielles où l’information visuelle de la cible et de la main était manipulée. Dans la tâche perceptive, une augmentation des erreurs d’orientation de la main a été observée avec le retrait des informations visuelles concernant la cible et/ou ou la main. Lorsque la vision de la main n’était pas permise, il a généralement été observé que les erreurs d’orientation de la main augmentaient avec le degré de rotation nécessaire pour aligner la main et la cible. Dans la tâche de mouvement d’orientation et d’atteinte simultanées, les erreurs ont également augmenté avec le retrait des informations visuelles. Toutefois, les patrons d’erreurs étaient différents de ceux observés dans la tâche de perception, et les erreurs d’orientation n’ont pas augmenté avec le degré de rotation nécessaire pour insérer la poignée dans la fente. En absence de vision de la main, il a été observé que les erreurs d’orientation étaient plus petites dans la tâche de mouvement que de perception, suggérant l’implication de la proprioception pour le contrôle de l’orientation spatiale de la main lors des mouvements d’orientation et d’atteinte simultanées. Le deuxième objectif de cette recherche était d’étudier l’influence de la vision et de la proprioception dans le contrôle en temps réel de l’orientation spatiale de la main. Dans une tâche d’orientation de la main suivie d’une atteinte manuelle (letter posting task 2), les sujets devaient d’abord aligner l’orientation de la même poignée avec la fente fixée dans les mêmes orientations, puis réaliser un mouvement d’atteinte sans modifier l’orientation initiale de la main. Une augmentation des erreurs initiales et finales a été observée avec le retrait des informations visuelles. Malgré la consigne de ne pas changer l’orientation initiale de la main, une diminution des erreurs d’orientation a généralement été observée suite au mouvement d’atteinte, dans toutes les conditions sensorielles testées. Cette tendance n’a pas été observée lorsqu’aucune cible explicite n’était présentée et que les sujets devaient conserver l’orientation de départ de la main pendant le mouvement d’atteinte (mouvement intransitif; letter-posting task 3). La diminution des erreurs pendant l’atteinte manuelle transitive vers une cible explicite (letter-posting task 2), malgré la consigne de ne pas changer l’orientation de la main pendant le mouvement, suggère un mécanisme de corrections automatiques pour le contrôle en temps réel de l’orientation spatiale de la main pendant le mouvement d’atteinte naturel vers une cible stationnaire. Le troisième objectif de cette recherche était d’évaluer la contribution de l’expérience visuelle pour la perception et le contrôle de l’orientation spatiale de la main. Des sujets aveugles ont été testés dans les mêmes tâches de perception et de mouvement. De manière générale, les sujets aveugles ont présenté les mêmes tendances que les sujets voyants testés dans la condition proprioceptive (sans vision), suggérant que l’expérience visuelle n’est pas nécessaire pour le développement d’un mécanisme de correction en temps réel de l’orientation spatiale de la main basé sur la proprioception. / The goal of this research was to study the contribution of vision and proprioception to the perception and control of hand orientation in human subjects. Spatial orientation of the hand is an important component of reaching and grasping movements. However, not much attention has been given to spatial hand orientation in the literature. To our knowledge, this study is the first to specifically investigate the influence of sensory information for the perception and on-line control of hand orientation during natural reaching movement to stationary targets. The first objective of this research was to study the contribution of vision and proprioception in perceptual orientation-matching and motor letter posting tasks. In the perceptual orientation-matching task, subjects attempted to passively or actively align a match handle, to a target that was fixed in different orientations. In the passive perceptual task, passive rotations of the forearm and wrist were imposed by the experimenter; whereas in the active perceptual task, the rotations were actively executed by the subjects. In letter posting task 1, subjects simultaneously reached and rotated the right hand to insert a match handle into a target slot fixed in the same orientations. The tasks were performed in different sensory conditions where the visual information about the target and the hand was manipulated. In the perceptual orientation-matching task, augmentation of hand orientation errors was observed with the withdrawal of visual information related to either the target and/or the hand. When full vision was not allowed, hand orientation errors were larger overall when larger rotations of the wrist were required to match the target, whether the rotations were made actively by the subject or were imposed passively by the experimenter. In letter posting task 1, augmentation of hand orientation errors was also observed with the withdrawal of visual information related to either the target and/or the hand. However, errors patterns were different from those observed in the perceptual task, and hand orientation errors were not larger for larger target orientations. Without vision of the hand, final hand orientation errors were smaller overall in letter-posting task 1 than in the orientation-matching task. This suggests the implication of the proprioceptive information for the control of spatial hand orientation during reach-and-orient movements. The second objective of this research was to study the influence of vision and proprioception in on-line control of spatial hand orientation. In letter posting task 2, subjects first aligned their hand to the angle of the target and then reached to it with the instruction not to change their initial hand orientation. The augmentation of initial and final errors was observed with the withdrawal of vision. Although subjects were instructed to not change their hand orientation, in all sensory condition tested, hand orientation changed overall during reaching in a way that reduced the initial orientation errors. This trend did not occur when there was no explicitly defined target toward which the subjects reached (letter-posting task 3; intransitive movement). The reduction in hand orientation errors during transitive reach in letter-posting task 2, even when told not to change it, suggests the engagement of an automatic error correction mechanism for hand orientation during natural reaching movements toward stationary targets. The third objective of this research was to investigate the contribution of visual experience to the perception and control of spatial orientation of the hand. Blind subjects were tested in the same perceptual and motor tasks. Overall, no differences were observed between performance of blind subjects and normally-sighted subjects tested without vision (proprioceptive condition), suggesting that prior visual experience is not necessary for the development of an on-line error correction mechanism for hand orientation guided by proprioceptive inputs.

Cette recherche a pour but d’évaluer le rôle de la vision et de la proprioception pour la perception et le contrôle de l’orientation spatiale de la main chez l’humain. L’orientation spatiale de la main est une composante importante des mouvements d’atteinte et de saisie. Toutefois, peu d’attention a été portée à l’étude de l’orientation spatiale de la main dans la littérature. À notre connaissance, cette étude est la première à évaluer spécifiquement l’influence des informations sensorielles et de l’expérience visuelle pour la perception et le contrôle en temps réel de l'orientation spatiale de la main pendant le mouvement d’atteinte naturel vers une cible stationnaire. Le premier objectif était d’étudier la contribution de la vision et de la proprioception dans des tâches de perception et de mouvement d’orientation de la main. Dans la tâche de perception (orientation-matching task), les sujets devaient passivement ou activement aligner une poignée de forme rectangulaire avec une cible fixée dans différentes orientations. Les rotations de l’avant-bras et du poignet étaient soit imposées par l’expérimentateur, soit effectuées par les sujets. Dans la tâche de mouvement d’orientation et d’atteinte simultanées (letter posting task 1), les sujets ont réalisé des mouvements d’atteinte et de rotation simultanées de la main afin d’insérer la poignée rectangulaire dans une fente fixée dans les mêmes orientations. Les tâches ont été réalisées dans différentes conditions sensorielles où l’information visuelle de la cible et de la main était manipulée. Dans la tâche perceptive, une augmentation des erreurs d’orientation de la main a été observée avec le retrait des informations visuelles concernant la cible et/ou ou la main. Lorsque la vision de la main n’était pas permise, il a généralement été observé que les erreurs d’orientation de la main augmentaient avec le degré de rotation nécessaire pour aligner la main et la cible. Dans la tâche de mouvement d’orientation et d’atteinte simultanées, les erreurs ont également augmenté avec le retrait des informations visuelles. Toutefois, les patrons d’erreurs étaient différents de ceux observés dans la tâche de perception, et les erreurs d’orientation n’ont pas augmenté avec le degré de rotation nécessaire pour insérer la poignée dans la fente. En absence de vision de la main, il a été observé que les erreurs d’orientation étaient plus petites dans la tâche de mouvement que de perception, suggérant l’implication de la proprioception pour le contrôle de l’orientation spatiale de la main lors des mouvements d’orientation et d’atteinte simultanées. Le deuxième objectif de cette recherche était d’étudier l’influence de la vision et de la proprioception dans le contrôle en temps réel de l’orientation spatiale de la main. Dans une tâche d’orientation de la main suivie d’une atteinte manuelle (letter posting task 2), les sujets devaient d’abord aligner l’orientation de la même poignée avec la fente fixée dans les mêmes orientations, puis réaliser un mouvement d’atteinte sans modifier l’orientation initiale de la main. Une augmentation des erreurs initiales et finales a été observée avec le retrait des informations visuelles. Malgré la consigne de ne pas changer l’orientation initiale de la main, une diminution des erreurs d’orientation a généralement été observée suite au mouvement d’atteinte, dans toutes les conditions sensorielles testées. Cette tendance n’a pas été observée lorsqu’aucune cible explicite n’était présentée et que les sujets devaient conserver l’orientation de départ de la main pendant le mouvement d’atteinte (mouvement intransitif; letter-posting task 3). La diminution des erreurs pendant l’atteinte manuelle transitive vers une cible explicite (letter-posting task 2), malgré la consigne de ne pas changer l’orientation de la main pendant le mouvement, suggère un mécanisme de corrections automatiques pour le contrôle en temps réel de l’orientation spatiale de la main pendant le mouvement d’atteinte naturel vers une cible stationnaire. Le troisième objectif de cette recherche était d’évaluer la contribution de l’expérience visuelle pour la perception et le contrôle de l’orientation spatiale de la main. Des sujets aveugles ont été testés dans les mêmes tâches de perception et de mouvement. De manière générale, les sujets aveugles ont présenté les mêmes tendances que les sujets voyants testés dans la condition proprioceptive (sans vision), suggérant que l’expérience visuelle n’est pas nécessaire pour le développement d’un mécanisme de correction en temps réel de l’orientation spatiale de la main basé sur la proprioception. / The goal of this research was to study the contribution of vision and proprioception to the perception and control of hand orientation in human subjects. Spatial orientation of the hand is an important component of reaching and grasping movements. However, not much attention has been given to spatial hand orientation in the literature. To our knowledge, this study is the first to specifically investigate the influence of sensory information for the perception and on-line control of hand orientation during natural reaching movement to stationary targets. The first objective of this research was to study the contribution of vision and proprioception in perceptual orientation-matching and motor letter posting tasks. In the perceptual orientation-matching task, subjects attempted to passively or actively align a match handle, to a target that was fixed in different orientations. In the passive perceptual task, passive rotations of the forearm and wrist were imposed by the experimenter; whereas in the active perceptual task, the rotations were actively executed by the subjects. In letter posting task 1, subjects simultaneously reached and rotated the right hand to insert a match handle into a target slot fixed in the same orientations. The tasks were performed in different sensory conditions where the visual information about the target and the hand was manipulated. In the perceptual orientation-matching task, augmentation of hand orientation errors was observed with the withdrawal of visual information related to either the target and/or the hand. When full vision was not allowed, hand orientation errors were larger overall when larger rotations of the wrist were required to match the target, whether the rotations were made actively by the subject or were imposed passively by the experimenter. In letter posting task 1, augmentation of hand orientation errors was also observed with the withdrawal of visual information related to either the target and/or the hand. However, errors patterns were different from those observed in the perceptual task, and hand orientation errors were not larger for larger target orientations. Without vision of the hand, final hand orientation errors were smaller overall in letter-posting task 1 than in the orientation-matching task. This suggests the implication of the proprioceptive information for the control of spatial hand orientation during reach-and-orient movements. The second objective of this research was to study the influence of vision and proprioception in on-line control of spatial hand orientation. In letter posting task 2, subjects first aligned their hand to the angle of the target and then reached to it with the instruction not to change their initial hand orientation. The augmentation of initial and final errors was observed with the withdrawal of vision. Although subjects were instructed to not change their hand orientation, in all sensory condition tested, hand orientation changed overall during reaching in a way that reduced the initial orientation errors. This trend did not occur when there was no explicitly defined target toward which the subjects reached (letter-posting task 3; intransitive movement). The reduction in hand orientation errors during transitive reach in letter-posting task 2, even when told not to change it, suggests the engagement of an automatic error correction mechanism for hand orientation during natural reaching movements toward stationary targets. The third objective of this research was to investigate the contribution of visual experience to the perception and control of spatial orientation of the hand. Blind subjects were tested in the same perceptual and motor tasks. Overall, no differences were observed between performance of blind subjects and normally-sighted subjects tested without vision (proprioceptive condition), suggesting that prior visual experience is not necessary for the development of an on-line error correction mechanism for hand orientation guided by proprioceptive inputs.