Periodicity in a delayed version of the kaldor trade cycle model

We are concerned with the Kaldor's trade cycle model under the effect of a delay which represents a gestation lag between a decision of investment and its effect on the capital stock. Taking the adjustment coefficient in the goods market as a bifurcation parameter, we achieve global branches of periodic solutions. In our setting the delay is a constant inherent to the specific economy. Copyright © 2013 Watam Press.

A rentabilidade das indústrias nacionais de cortiça: na ótica da gestão de tesouraria.

Dissertação de Mestrado Apresentado ao Instituto de Contabilidade e Administração do Porto para a obtenção do grau de Mestre em Contabilidade e Finanças, sob orientação de Mestre Adalmiro Álvaro Malheiro de Castro Andrade Pereira.

Impacto da gestão de fundo de maneio na rendibilidade das empresas portuguesas: sector da cortiça

O estudo analisa o impacto da gestão de Fundo de maneio na rendibilidade de algumas empresas Portuguesas no sector da cortiça, sendo a amostra final constituída por 354 empresas no período de 2007 a 2013. O contributo para a literatura existente relaciona-se com a falta de estudos sobre o tema da relação entre a gestão de Fundo de Maneio e a rendibilidade das empresas do sector da cortiça. A relação entre a eficiência da gestão de Fundo de Maneio e a rendibilidade das empresas foi analisada usando dados em painel e a metodologia utilizada consistiu na análise de regressão utilizando o Modelo de Efeitos fixos. De entre os resultados obtidos, constatamos que os gestores podem aumentar a rendibilidade das empresas, reduzindo o prazo médio de existências e alargando o prazo médio de pagamentos. Não foi possível provar a existência de relação entre a duração do net trade cycle ou do prazo médio de recebimentos e a rendibilidade das empresas. Por outro lado, o grau de alavancagem operacional apresenta um efeito positivo sobre a rendibilidade da empresa.

O impacto da gestão de fundo de maneio na rendibilidade das empresas durante a crise financeira: evidência europeia

Dissertação de mestrado em Finanças

Käyttöpääoman mittaaminen valmistavassa teollisuudessa

Käyttöpääoman hallinta on yrityksille tärkeä osa talouden hallintaa. Tehokkaalla käyttöpääoman hallinnalla pystytään vaikuttamaan positiivisesti yrityksen kannattavuuteen ja maksuvalmiuteen. Tämän tutkielman tavoitteena on selvittää käytetyimmät käyttöpääoman mittarit prosessinäkökulmasta, sekä analysoida mittareiden antamia tuloksia. Prosessinäkökulman mittarit kertovat käyttöpääoman tarpeen päivissä. Prosessinäkökulman mittareiden laskemiseksi tarvitaan harvemmin tietoa, joka on vain ylimmän johdon käytettävissä. Tutkielma on kirjallisuustutkimus, jonka lähteinä on käytetty kirjallisuutta ja tieteellisiä artikkeleita. Empiirisessä osassa on laskettu käyttöpääomamittareiden tulokset kolmelle valmistavan teollisuuden yritykselle, sekä analysoitu tutkimustuloksia. Tunnusluvut on koottu yritysten julkisten tilinpäätösten perusteella. Käyttöpääomalle löytyi prosessinäkökulmasta vain muutamia mittareita. Kaikki käyttöpääomalle löydetyt prosessinäkökulman mittarit olivat joko käyttöpääomasyklin osakokonaisuuksia tai sen variaatioita. Käyttöpääomasykli osoittautui käytetyimmäksi prosessinäkökulman mittariksi tutkielmassa käytettyjen artikkeleiden perusteella.

A velocidade de ajuste das necessidades de capital de giro : um estudo sobre amostra de empresas listadas na BM&FBovespa

O presente estudo - até onde se sabe inédito no Brasil – possui como principal objetivo avaliar alguns determinantes das necessidades de capital de giro comumente estudados na literatura e analisar de que forma as empresas se movimentam em direção a uma meta (target) de Net Trade Cycle (similar ao Ciclo de Caixa - CCC). Sabemos que o tema capital de giro ainda carece de teorias mais robustas dentro da área de finanças, e poucos estudos ainda são encontrados na literatura. Aqueles que decidem estudá-lo, observam que dado o seu atual estágio, ele tem sido pesquisado com o suporte de bases teóricas mais consolidadas, como por exemplo estrutura de capitais. Esses estudos têm se utilizado muito do conceito de meta para determinar a estrutura ótima de capitais, e com qual velocidade de ajuste procura-se adequar essa estrutura como forma de otimizar seus recursos. O fato de ainda não existir definições e/ou teorias mais definidas sobre o tema foi o grande motivador para a realização desse estudo, que emprega a velocidade de ajuste em direção a uma meta de capital de giro, utilizando como técnica para suporte a esse objetivo o Modelo de Ajustamento Parcial (MAP) e o Generalized Method of Moments (GMM). Com essa combinação inédita no mercado brasileiro quando o assunto é capital de giro, esperamos trazer novas contribuições para as comunidades acadêmicas e empresariais. Para a obtenção dos dados que compõem esse estudo de caráter quantitativo, utilizamos informações existentes na Economatica® e BCB – Banco Central do Brasil. Nessas bases de dados utilizamos os demonstrativos financeiros trimestrais entre os períodos de 31/Dez./2007 a 30/Jun./2014 (ajustados por inflação – IPCA) das empresas listadas na BM&FBovespa que possuíssem pelos menos 15 períodos (trimestres) consecutivos de dados, com isso chegamos a um total de um pouco mais de 2 mil observações e 105 empresas. Quanto ao método, utilizamos Painel de Dados Dinâmico (desbalanceado) e as seguintes técnicas foram empregadas como forma de atender ao principal objetivo do estudo (“Qual é a velocidade de ajuste das Necessidades de Capital de Giro?”): Modelo de Ajustamento Parcial para a análise dos determinantes das necessidades de capital de giro e movimentação em direção a uma meta e; Generalized Method of Moments (GMM) como técnica de controle aos possíveis efeitos de endogeneidade (BLUNDELL e BOND, 1998) e solução para o problema de autocorrelação residual (PIRES, ZANI e NAKAMURA, 2013, p. 19).

Quantifying carbon-cycle feedbacks

Perturbations to the carbon cycle could constitute large feedbacks on future changes in atmospheric CO2 concentration and climate. This paper demonstrates how carbon cycle feedback can be expressed in formally similar ways to climate feedback, and thus compares their magnitudes. The carbon cycle gives rise to two climate feedback terms: the concentration–carbon feedback, resulting from the uptake of carbon by land and ocean as a biogeochemical response to the atmospheric CO2 concentration, and the climate–carbon feedback, resulting from the effect of climate change on carbon fluxes. In the earth system models of the Coupled Climate–Carbon Cycle Model Intercomparison Project (C4MIP), climate–carbon feedback on warming is positive and of a similar size to the cloud feedback. The concentration–carbon feedback is negative; it has generally received less attention in the literature, but in magnitude it is 4 times larger than the climate–carbon feedback and more uncertain. The concentration–carbon feedback is the dominant uncertainty in the allowable CO2 emissions that are consistent with a given CO2 concentration scenario. In modeling the climate response to a scenario of CO2 emissions, the net carbon cycle feedback is of comparable size and uncertainty to the noncarbon–climate response. To quantify simulated carbon cycle feedbacks satisfactorily, a radiatively coupled experiment is needed, in addition to the fully coupled and biogeochemically coupled experiments, which are referred to as coupled and uncoupled in C4MIP. The concentration–carbon and climate–carbon feedbacks do not combine linearly, and the concentration–carbon feedback is dependent on scenario and time.

An analysis of the effects of preferential trade policies through the estimation of quantitative models: the case of Portugal.

Doutoramento em Economia.

Essays on oil price fluctuations and macroeconomic activity

Dans cette thèse, je me suis intéressé aux effets des fluctuations du prix de pétrole sur l'activité macroéconomique selon la cause sous-jacente ces fluctuations. Les modèles économiques utilisés dans cette thèse sont principalement les modèles d'équilibre général dynamique stochastique (de l'anglais Dynamic Stochastic General Equilibrium, DSGE) et les modèles Vecteurs Autorégressifs, VAR. Plusieurs études ont examiné les effets des fluctuations du prix de pétrole sur les principaux variables macroéconomiques, mais très peu d'entre elles ont fait spécifiquement le lien entre les effets des fluctuations du prix du pétrole et la l'origine de ces fluctuations. Pourtant, il est largement admis dans les études plus récentes que les augmentations du prix du pétrole peuvent avoir des effets très différents en fonction de la cause sous-jacente de cette augmentation. Ma thèse, structurée en trois chapitres, porte une attention particulière aux sources de fluctuations du prix de pétrole et leurs impacts sur l'activité macroéconomique en général, et en particulier sur l'économie du Canada. Le premier chapitre examine comment les chocs d'offre de pétrole, de demande agrégée, et de demande de précaution de pétrole affectent l'économie du Canada, dans un Modèle d'équilibre Général Dynamique Stochastique estimé. L'estimation est réalisée par la méthode Bayésienne, en utilisant des données trimestrielles canadiennes sur la période 1983Q1 à 2010Q4. Les résultats montrent que les effets dynamiques des fluctuations du prix du pétrole sur les principaux agrégats macro-économiques canadiens varient en fonction de leurs sources. En particulier, une augmentation de 10% du prix réel du pétrole causée par des chocs positifs sur la demande globale étrangère a un effet positif significatif de l'ordre de 0,4% sur le PIB réel du Canada au moment de l'impact et l'effet reste positif sur tous les horizons. En revanche, une augmentation du prix réel du pétrole causée par des chocs négatifs sur l'offre de pétrole ou par des chocs positifs de la demande de pétrole de précaution a un effet négligeable sur le PIB réel du Canada au moment de l'impact, mais provoque une baisse légèrement significative après l'impact. En outre, parmi les chocs pétroliers identifiés, les chocs sur la demande globale étrangère ont été relativement plus important pour expliquer la fluctuation des principaux agrégats macroéconomiques du Canada au cours de la période d'estimation. Le deuxième chapitre utilise un modèle Structurel VAR en Panel pour examiner les liens entre les chocs de demande et d'offre de pétrole et les ajustements de la demande de travail et des salaires dans les industries manufacturières au Canada. Le modèle est estimé sur des données annuelles désagrégées au niveau industriel sur la période de 1975 à 2008. Les principaux résultats suggèrent qu'un choc positif de demande globale a un effet positif sur la demande de travail et les salaires, à court terme et à long terme. Un choc négatif sur l'offre de pétrole a un effet négatif relativement faible au moment de l'impact, mais l'effet devient positif après la première année. En revanche, un choc positif sur la demande précaution de pétrole a un impact négatif à tous les horizons. Les estimations industrie-par-industrie confirment les précédents résultats en panel. En outre, le papier examine comment les effets des différents chocs pétroliers sur la demande travail et les salaires varient en fonction du degré d'exposition commerciale et de l'intensité en énergie dans la production. Il ressort que les industries fortement exposées au commerce international et les industries fortement intensives en énergie sont plus vulnérables aux fluctuations du prix du pétrole causées par des chocs d'offre de pétrole ou des chocs de demande globale. Le dernier chapitre examine les implications en terme de bien-être social de l'introduction des inventaires en pétrole sur le marché mondial à l'aide d'un modèle DSGE de trois pays dont deux pays importateurs de pétrole et un pays exportateur de pétrole. Les gains de bien-être sont mesurés par la variation compensatoire de la consommation sous deux règles de politique monétaire. Les principaux résultats montrent que l'introduction des inventaires en pétrole a des effets négatifs sur le bien-être des consommateurs dans chacun des deux pays importateurs de pétrole, alors qu'il a des effets positifs sur le bien-être des consommateurs dans le pays exportateur de pétrole, quelle que soit la règle de politique monétaire. Par ailleurs, l'inclusion de la dépréciation du taux de change dans les règles de politique monétaire permet de réduire les coûts sociaux pour les pays importateurs de pétrole. Enfin, l'ampleur des effets de bien-être dépend du niveau d'inventaire en pétrole à l'état stationnaire et est principalement expliquée par les chocs sur les inventaires en pétrole.

Hiánygazdaság − többletgazdaság. Tanulmány a piac elméletéről – II. rész = Shortage economy - surplus economy. A study on market theory II

A főáramlat közgazdászai elismerik, hogy a szocialista rendszert a krónikus hiány jellemezte, de úgy vélik, hogy a kapitalista rendszerben - kisebb vagy nagyobb ingadozások közepette - piaci egyensúly uralkodik. Ezzel szemben a tanulmány két piaci állapotot állít egymással szembe. Az egyikben dominálnak a túlkeresleti jelenségek, bár előfordulnak túlkínálati jelenségek is, ezt nevezi a szerző hiánygazdaságnak. A másikban dominálnak a túlkínálati jelenségek, bár előfordulnak túlkeresleti jelenségek is, amit a szerző többletgazdaságnak nevez. A tanulmány II. része összefoglalja a tanulmány fő állításait. Ezek szerint a szocialista rendszer veleszületett immanens tulajdonsága a hiánygazdaság, míg a kapitalista rendszer veleszületett immanens tulajdonsága a többletgazdaság létrehozása és állandó reprodukciója. Állami beavatkozások erősíthetik vagy gyengíthetik ezeket a genetikus tulajdonságokat, de nem szüntethetik meg. A tanulmány áttekinti a többletgazdaság kedvező és kedvezőtlen hatásait. A kedvező hatások között különleges nyomatékkal emeli ki, hogy a többlet (elsősorban többletkapacitások) nélkül nem alakulhat ki a termelők, illetve az eladók rivalizálása, ami az innovációs folyamat legfontosabb hajtóereje. A többletgazdaság általános esetének vizsgálata után különböző speciális esetekkel foglalkozik a tanulmány: a gazdaság konjunkturális hullámzásával, a hadigazdasággal, a modern kapitalizmusban mutatkozó történelmi léptékű változásokkal, valamint a szocialista rendszeren belül megjelent piacorientált reformokkal és a posztszocialista átmenettel. ____ Mainstream economists recognize that the socialist system was marked by chronic shortage, but they consider that the capitalist system exhibits market equilibrium, give or take some greater or lesser fluctuations. This study, however, contrasts two market states. One is dominated by phenomena of excess demand, though instances of excess supply appear as well; this the author calls a shortage economy. The other is dominated by phenomena of excess supply, though instances of excess demand appear as well; this the author terms a surplus economy. Part II of the study starts by summing up its main propositions. Just as the shortage economy is an intrinsic, immanent trait of the socialist system, so the creation and continual reproduction of the surplus economy is an intrinsic, immanent trait of the capitalist system. Such genetic traits may be strengthened or weakened by state intervention, but not eliminated by it. The study reviews the favourable and detrimental effects of the surplus economy. Of the favourable effects, it is emphasized that without surplus there cannot develop among producers or sellers the rivalry that provides the main impetus for the innovation process. Having examined the general case of the surplus economy, the study turns to various special cases: to the trade-cycle fluctuations of the economy, the war economy, the historic changes appearing in modern capitalism, the market-oriented reforms that appear within the socialist system, and the post-socialist transition.

Trade and Business Cycle Correlations in Asia-Pacific

Recent empirical studies challenge the traditional theory of optimum currency areas by arguing that a monetary union enhances trade and business cycle co-movements among its member countries sufficiently as to obviate the need for national monetary policy. This paper examines the empirical relationship between trade and business cycle correlations among thirteen Asia-Pacific countries, paying particular attention to the structural characteristics of their economies and other issues not explored fully in the literature. According to our result, although trade is relevant to the business cycles of individual countries, the main determinant of their international correlations is not the geographical structure of their trade but what they produce and export --more specifically the extent to which their output and exports are concentrated on electronic products.

Trade, Exchange Rates, and Macroeconomic Dynamics in East Asia: Why the Electronics Cycle Matters

Against the background of increasing regional trade and investment, there is growing interest in monetary and macroeconomic policy coordination in East Asia. Although there is a sizable literature on macroeconomic linkages among East Asian countries and the potential merit of policy coordination in the region, the existing studies tend to examine these issues exclusively in terms of macroeconomic variables and do not consider how these aggregate variables are influenced by one prominent feature of a number of East Asian economies: their heavy dependence on the electronics industry. Although active engagement in the global electronics industry has been a powerful growth engine for the Asian countries, it has also left their economies vulnerable to cyclical fluctuations in the world electronics market. As the cycle of the global electronics industry exerts profound impacts on the medium-term dynamics of the Asian economies, it is imperative to take an explicit account of its influence when studying the way in which the regional economies are linked to one another and how this relationship can be altered by a specific policy initiative. We illustrate the importance of this point by examining recent studies on: (1) trade competition between China andother Asian countries and the role of the Chinese renminbi therein; and (2) the effect offluctuations in the yen/dollar exchange rate on the regional economies.

Integrating environmental and economic life cycle analysis in product development: a material selection case study

Purpose Achieving sustainability by rethinking products, services and strategies is an enormous challenge currently laid upon the economic sector, in which materials selection plays a critical role. In this context, the present work describes an environmental and economic life cycle analysis of a structural product, comparing two possible material alternatives. The product chosen is a storage tank, presently manufactured in stainless steel (SST) or in a glass fibre reinforced polymer composite (CST). The overall goal of the study is to identify environmental and economic strong and weak points related to the life cycle of the two material alternatives. The consequential win-win or trade-off situations will be identified via a Life Cycle Assessment/Life Cycle Costing (LCA/LCC) integrated model. Methods The LCA/LCC integrated model used consists in applying the LCA methodology to the product system, incorporating, in parallel, its results into the LCC study, namely those of the Life Cycle Inventory (LCI) and the Life Cycle Impact Assessment (LCIA). Results In both the SST and CST systems the most significant life cycle phase is the raw materials production, in which the most significant environmental burdens correspond to the Fossil fuels and Respiratory inorganics categories. The LCA/LCC integrated analysis shows that the CST has globally a preferable environmental and economic profile, as its impacts are lower than those of the SST in all life cycle stages. Both the internal and external costs are lower, the former resulting mainly from the composite material being significantly less expensive than stainless steel. This therefore represents a full win-win situation. As a consequence, the study clearly indicates that using a thermoset composite material to manufacture storage tanks is environmentally and economically desirable. However, it was also evident that the environmental performance of the CST could be improved by altering its End-of-Life stage. Conclusions The results of the present work provide enlightening insights into the synergies between the environmental and the economic performance of a structural product made with alternative materials. Further, they provide conclusive evidence to support the integration of environmental and economic life cycle analysis in the product development processes of a manufacturing company, or in some cases even in its procurement practices.

Energy and delay trade-off of the GTS allocation mechanism in IEEE 802.15.4 for wireless sensor networks

The IEEE 802.15.4 protocol proposes a flexible communication solution for Low-Rate Wireless Personal Area Networks (LR-WPAN) including wireless sensor networks (WSNs). It presents the advantage to fit different requirements of potential applications by adequately setting its parameters. When in beaconenabled mode, the protocol can provide timeliness guarantees by using its Guaranteed Time Slot (GTS) mechanism. However, power-efficiency and timeliness guarantees are often two antagonistic requirements in wireless sensor networks. The purpose of this paper is to analyze and propose a methodology for setting the relevant parameters of IEEE 802.15.4-compliant WSNs that takes into account a proper trade-off between power-efficiency and delay bound guarantees. First, we propose two accurate models of service curves for a GTS allocation as a function of the IEEE 802.15.4 parameters, using Network Calculus formalism. We then evaluate the delay bound guaranteed by a GTS allocation and express it as a function of the duty cycle. Based on the relation between the delay requirement and the duty cycle, we propose a power-efficient superframe selection method that simultaneously reduces power consumption and enables meeting the delay requirements of real-time flows allocating GTSs. The results of this work may pave the way for a powerefficient management of the GTS mechanism in an IEEE 802.15.4 cluster.