951 resultados para salinity shocks
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This paper assesses empirically the effect of oil price shocks on Portuguese aggregate economic activity, industrial production and price level. We take the usual multivariate VAR methodology to investigate the magnitude and stability of this relationship. In doing so, we follow the approach presented in the recent literature and adopt different oil price specifications. We conclude that, as for most industrialized countries, the nature of this relationship changed in the mid-1980s. Furthermore, we show that the main Portuguese macroeconomic variables have become progressively less responsive to oil shocks and the adjustment towards equilibrium has become increasingly faster.
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Nuestra preocupación reside en estudiar empíricamente el mecanismo de transmisión internacional de ciclos económicos a economías pequeñas y menos desarrolladas (LDC), evaluando el impacto de los shocks en los términos de intercambio en países dónde existen imperfecciones en el mercado crediticio que imponen severas restricciones en el financiamiento de la inversión doméstica y al crecimiento económico. Primero, analizamos si la cuenta corriente responde de manera asimétrica a movimientos de largo plazo en los términos de intercambio. La hipótesis es que “en los buenos tiempos” cuando se produce una mejora permanente en términos de intercambio (y con ello el nivel de ingreso) los individuos no elevan su consumo en un monto acorde con la mejora de su ingreso (permanente) sino que ahorran una fracción del aumento en su dotación para hacer frente a una reversión en la mejora en los términos de intercambios (aunque ésta sea transitoria) en el futuro. En consecuencia, la cuenta corriente (diferencia entre ingreso y absorción) responde de manera positiva a un shock permanente en los términos de intercambio, ya que el individuo ahorra de manera cautelosa –debido a que sabe que no le prestarán para suavizar consumo - aún suponiendo que en el futuro tendrá una reversión transitoria de su ingreso. Segundo, estudiamos la relación dinámica entre los términos de intercambio y la tasa de interés en la economía pequeña abierta y con imperfecciones en el mercado crediticio (información asimétrica). La hipótesis es que la economía doméstica tiene que soportar una prima de riesgo que eleva el costo de la inversión y retarda el crecimiento (Gertler y Rogoff; 1990). Esta prima de riesgo depende, además, en forma negativa del nivel del colateral que tenga la economía. El colateral es la dotación de recursos naturales, por ejemplo, que la economía posee a los fines garantizar el cumplimiento de las obligaciones contraídas (en el modelo presentado las actividades dónde se invierten son independientes del colateral). La hipótesis establecida indica que los cambios en los términos de intercambio generan un aumento del colateral de la economía y una reducción del riesgo país: aumentos en los términos de intercambio reducen la prima de riesgo de la economía que opera en mercados de capitales con asimetrías de información, y como consecuencia aumentarían los ingresos de capitales. De esta forma, se estaría encontrando una explicación a la denominada “Paradoja de Lucas”. Finalmente, el proyecto estudia la conexión entre dos variables “clave” en la economía de los países emergentes: la relación entre los términos de intercambio y el tipo de cambio real. Argumentamos que los efectos de las mejoras de los términos de intercambio sobre los flujos de capitales externos tienden a ser sobreestimadas si no se consideran los efectos “secundarios” de éstas sobre el tipo de cambio real de la economía pequeña menos desarrollada. En este proyecto se controlan estadísticamente esta relación. La estrategia empírica elegida resulta en aplicar a un panel (constituido por dieciocho países de Latinoamérica) el método generalizado de momentos (GMM) a dos modelos de regresión estadística a los fines de abordar de manera eficiente el problema de la endogeneidad de la variable dependiente que actúa como regresor rezagado. La estrategia de estimación elegida enfatiza el análisis de la relación dinámica de las variables económicas incluidas en el análisis. The paper analyzes the general problem related to the transmission of economic cycles to Small Open Economies. The analysis focuses on terms-of-trade shocks, which are considered one of the major sources of income volatility in developing economies. Specifically, we tackle the problem related to the impact of terms-of-trade shocks in Less Developed SOEs. ‘Less Developed SOEs’ are understood as those countries who have borrowing constraints. First, we put to a test the hypothesis of asymmetric response of current account to terms-of-trade shocks (the impact of the shock on current account differs depending whether it is positive or negative), which originates from considering binding restrictions in international capital markets (Agénor and Aizenman; 2004). Second, we investigate about the main determinants of External Capital Flows (ECF) directed to Developing Countries. We put to a test the Gertler and Rogoff (1990) hypothesis that a “risky rate” arises in that markets because the economy has not sufficient amount of wealth to “collateralize” the capital she needs to borrow to take advantage of the investment opportunities she has and additionally because the lender does not have the chance of observing what the borrowed does with the funds (that is information asymmetry arises because the lender can check the realized output of investment but he can not observe if he really invest in the project or secretly lend abroad). Finally, Following Prasad, E. S., Rajan and R. Subramanian, A (2007) we measure the relationship between external capital flows and domestic currency overvaluation. We run a panel GMM estimation for a set of 18 Latin American Countries during the period 1973-2008.
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The present work deal t wi th an experiment under field conditions and a laboratory test of soil incubation the objectives were as follows: a. to study effects on soybean grain product ion and leaf composition of increasing doses of potassium chloride applied into the soil through two methods of distribution; b. to observe chemical modifications in the soils incubated with increasing doses of potassium chloride; and, c. to correlate field effects with chemical alterations observed in the incubation test, The field experiment was carried out in a Red Latosol (Haplustox) with soybean cultivar UFV - 1. Potassium chloride was distributed through two methods: banded (5 cm below and 5 cm aside of the seed line) and broadcasted and plowed-down. Doses used were: 0; 50; 100 and 200 kg/ha of K2O. Foliar samples were taken at flowering stage. Incubation test were made in plastic bags with 2 kg of air dried fine soil, taken from the arable layer of the field experiment, with the following doses of KC1 p,a. : 0; 50; 100; 200; 400; 800; 1,600; 3.200; 6,400 and 12,800 kg/ha of K(2)0. In the conditions observed during the present work, results allowed the following conclusions: A response by soybean grain production for doses of potassium chloride, applied in both ways, banded or broadcasted, was not observed. Leaf analysis did not show treatment influence over the leaf contents for N, P, K, Ca, Mg, and CI, Potassium chloride salinity effects in both methods of distribution for all the tested closes were not observed.
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Metamysidopsis atlantica elongata (Bascescu, 1968) is a common mysid in the surf zone of sandy beaches from the state of Rio Grande do Sul, Brazil, where it is frequently recorded forming dense aggregations. Trough laboratory trials, behavioral responses to salinity (10, 20, 25, 28, 30, 40 e 45), temperature (10, 15, 20, 30±1ºC) and light (yes/no) were tested using adult males, adult females and juveniles. Although there was no response to temperature, the species showed clear response to salinity and light. In the presence of light, organisms remained in the bottom of the aquaria, but moved to surface when bottom salinities were increased. In the absence of light, adults moved to the surface. However, juveniles moved down to or remained on the bottom, maybe as a response to avoid adult predation.
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The purpose of this paper is twofold. First, we construct a DSGE model which spells out explicitly the instrumentation of monetary policy. The interest rate is determined every period depending on the supply and demand for reserves which in turn are affected by fundamental shocks: unforeseeable changes in cash withdrawal, autonomous factors, technology and government spending. Unexpected changes in the monetary conditions of the economy are interpreted as monetary shocks. We show that these monetary shocks have the usual effects on economic activity without the need of imposing additional frictions as limited participation in asset markets or sticky prices. Second, we show that this view of monetary policy may have important consequences for empirical research. In the model, the contemporaneous correlations between interest rates, prices and output are due to the simultaneous effect of all fundamental shocks. We provide an example where these contemporaneous correlations may be misinterpreted as a Taylor rule. In addition, we use the sign of the impact responses of all shocks on output, prices and interest rates derived from the model to identify the sources of shocks in the data.
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This paper analyzes the propagation of monetary policy shocks through the creation of credit in an economy. Models of the monetary transmission mechanism typically feature responses which last for a few quarters contrary to what the empirical evidence suggests. To propagate the impact of monetary shocks over time, these models introduce adjustment costs by which agents find it optimal to change their decisions slowly. This paper presents another explanation that does not rely on any sort of adjustment costs or stickiness. In our economy, agents own assets and make occupational choices. Banks intermediate between agents demanding and supplying assets. Our interpretation is based on the way banks create credit and how the monetary authority affects the process of financial intermediation through its monetary policy. As the central bank lowers the interest rate by buying government bonds in exchange for reserves, high productive entrepreneurs are able to borrow more resources from low productivity agents. We show that this movement of capital among agents sets in motion a response of the economy that resembles an expansionary phase of the cycle.
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Two claims pervade the literature on the political economy of market reforms: that economic crises cause reforms; and that crises matter because they bring into question the validity of the economic model held to be responsible for them. Economic crises are said to spur a process of learning that is conducive to the abandonment of failing models and to the adoption of successful models. But although these claims have become the conventional wisdom, they have been hardly tested empirically due to the lack of agreement on what constitutes a crisis and to difficulties in measuring learning from them. I propose a model of rational learning from experience and apply it to the decision to open the economy. Using data from 1964 through 1990, I show that learning from the 1982 debt crisis was relevant to the first wave of adoption of an export promotion strategy, but learning was conditional on the high variability of economic outcomes in countries that opened up to trade. Learning was also symbolic in that the sheer number of other countries that liberalized was a more important driver of others’ decisions to follow suit.
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Projecte de recerca elaborat a partir d’una estada a la National Oceanography Centre of Southampton (NOCS), Gran Bretanya, entre maig i juliol del 2006. La possibilitat d’obtenir una estimació precissa de la salinitat marina (SSS) és important per a investigar i predir l’extensió del fenòmen del canvi climàtic. La missió Soil Moisture and Ocean Salinity (SMOS) va ser seleccionada per l’Agència Espacial Europea (ESA) per a obtenir mapes de salinitat de la superfície marina a escala global i amb un temps de revisita petit. Abans del llençament de SMOS es preveu l’anàlisi de la variabilitat horitzontal de la SSS i del potencial de les dades recuperades a partir de mesures de SMOS per a reproduir comportaments oceanogràfics coneguts. L’objectiu de tot plegat és emplenar el buit existent entre les fonts de dades d’entrada/auxiliars fiables i les eines desenvolupades per a simular i processar les dades adquirides segons la configuració de SMOS. El SMOS End-to-end Performance Simulator (SEPS) és un simulador adhoc desenvolupat per la Universitat Politècnica de Catalunya (UPC) per a generar dades segons la configuració de SMOS. Es va utilitzar dades d’entrada a SEPS procedents del projecte Ocean Circulation and Climate Advanced Modeling (OCCAM), utilitzat al NOCS, a diferents resolucions espacials. Modificant SEPS per a poder fer servir com a entrada les dades OCCAM es van obtenir dades de temperatura de brillantor simulades durant un mes amb diferents observacions ascendents que cobrien la zona seleccionada. Les tasques realitzades durant l’estada a NOCS tenien la finalitat de proporcionar una tècnica fiable per a realitzar la calibració externa i per tant cancel•lar el bias, una metodologia per a promitjar temporalment les diferents adquisicions durant les observacions ascendents, i determinar la millor configuració de la funció de cost abans d’explotar i investigar les posibiltats de les dades SEPS/OCCAM per a derivar la SSS recuperada amb patrons d’alta resolució.
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This paper analyzes the persistence of shocks that affect the real exchange rates for a panel of seventeen OECD developed countries during the post-Bretton Woods era. The adoption of a panel data framework allows us to distinguish two different sources of shocks, i.e. the idiosyncratic and the common shocks, each of which may have di¤erent persistence patterns on the real exchange rates. We first investigate the stochastic properties of the panel data set using panel stationarity tests that simultaneously consider both the presence of cross-section dependence and multiple structural breaks that have not received much attention in previous persistence analyses. Empirical results indicate that real exchange rates are non-stationary when the analysis does not account for structural breaks, although this conclusion is reversed when they are modeled. Consequently, misspecification errors due to the non-consideration of structural breaks leads to upward biased shocks' persistence measures. The persistence measures for the idiosyncratic and common shocks have been estimated in this paper always turn out to be less than one year.
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Employing the financial accelerator (FA) model of Bernanke, Gertler and Gilchrist (1999) enhanced to include a shock to the FA mechanism, we construct and study shocks to the efficiency of the financial sector in post-war US business cycles. We find that financial shocks are very tightly linked with the onset of recessions, more so than TFP or monetary shocks. The financial shock invariably remains contractionary for sometime after recessions have ended. The shock accounts for a large part of the variance of GDP and is strongly negatively correlated with the external finance premium. Second-moments comparisons across variants of the model with and without a (stochastic) FA mechanism suggests the stochastic FA model helps us understand the data.
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This paper contributes to the on-going empirical debate regarding the role of the RBC model and in particular of technology shocks in explaining aggregate fluctuations. To this end we estimate the model’s posterior density using Markov-Chain Monte-Carlo (MCMC) methods. Within this framework we extend Ireland’s (2001, 2004) hybrid estimation approach to allow for a vector autoregressive moving average (VARMA) process to describe the movements and co-movements of the model’s errors not explained by the basic RBC model. The results of marginal likelihood ratio tests reveal that the more general model of the errors significantly improves the model’s fit relative to the VAR and AR alternatives. Moreover, despite setting the RBC model a more difficult task under the VARMA specification, our analysis, based on forecast error and spectral decompositions, suggests that the RBC model is still capable of explaining a significant fraction of the observed variation in macroeconomic aggregates in the post-war U.S. economy.
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This paper examines the rise in European unemployment since the 1970s by introducing endogenous growth into an otherwise standard New Keynesian model with capital accumulation and unemployment. We subject the model to an uncorrelated cost push shock, in order to mimic a scenario akin to the one faced by central banks at the end of the 1970s. Monetary policy implements a disinfl ation by following an interest feedback rule calibrated to an estimate of a Bundesbank reaction function. 40 quarters after the shock has vanished, unemployment is still about 1.8 percentage points above its steady state. Our model also broadly reproduces cross country differences in unemployment by drawing on cross country differences in the size of cost push shock and the associated disinfl ation, the monetary policy reaction function and the wage setting structure.
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The implications of local currency pricing (LCP) for monetary regime choice are analysed for a country facing foreign monetary shocks. In this analysis expenditure switching is potentially welfare reducing. This contrasts with the existing LCP literature, which focuses on productivity shocks and thus analyses a world where expenditure switching is welfare enhancing. This paper shows that, when home and foreign producers follow LCP, expenditure switching is absent and a floating rate is preferred by the home country. But when only home producers follow LCP, expenditure switching is present and a fixed rate can be welfare enhancing for the home country.
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This study examines the impact of macro-liquidity shocks on the returns of UK stock portfolios sorted on the basis of a series of micro-liquidity measures. The macro-liquidity shocks are extracted on the meeting days of the Bank of England Monetary Policy Committee relative to market expectations embedded in futures contracts on the 3-month LIBOR during the period June 1999- December 2009. We report definitive evidence that these shocks are transmitted to the cross-section of liquidity-sorted portfolios, with most liquid stocks playing a very active role. Our results emphatically document that the shocks-returns relationship has reversed its sign during the recent financial crisis; the standard inverse relationship between interest rate surprises and portfolios’ returns before the crisis has turned into positive during the crisis. This finding confirms the inability of interest rate cuts to boost returns in the shortrun during the crisis, because these were perceived by market participants as a signal of a deteriorating economic outlook.