983 resultados para Reaction function


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This paper uses Swiss data to study the real long-run effects of monetary policy. Daily unexpected changes in the monetary base are found to be negatively correlated with security price changes. This result is unaffected when, implicitly following Geske and Roll (1983), we try to measure the autonomous component of monetary policy by taking into account a reaction function of monetary policy to changes in real variables.

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Recently, steady economic growth rates have been kept in Poland and Hungary. Money supplies are growing rather rapidly in these economies. In large, exchange rates have trends of depreciation. Then, exports and prices show the steady growth rates. It can be thought that per capita GDPs are in the same level and development stages are similar in these two countries. It is assumed that these two economies have the same export market and export goods are competing in it. If one country has an expansion of monetary policy, price increase and interest rate decrease. Then, exchange rate decrease. Exports and GDP will increase through this phenomenon. At the same time, this expanded monetary policy affects another country through the trade. This mutual relationship between two countries can be expressed by the Nash-equilibrium in the Game theory. In this paper, macro-econometric models of Polish and Hungarian economies are built and the Nash- equilibrium is introduced into them.

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In a strategic trade policy, it is assumed, in this paper, that a government changes disbursement or levy method so that the reaction function of home firm approaches infinitely close to that of foreign firm. In the framework of Bertrand-Nash equilibrium, Eaton and Grossman[1986] showed that export tax is preferable to export subsidy. In this paper, it is shown that export subsidy is preferable to export tax in some cases in the framework of Bertrand-Nash equilibrium, considering the uncertainty in demand. Historically, many economists mentioned non-linear subsidy or tax. However, optimum solution of it has not yet been shown. The optimum solution is shown in this paper.

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Há mais de uma década o controle dos níveis de preço na economia brasileira é realizado dentro do escopo do Regime de Metas de Inflação, que utiliza modelos macroeconômicos como instrumentos para guiar as tomadas de decisões sobre política monetária. Após um período de relativo êxito (2006 - 2009), nos últimos anos apesar dos esforços das autoridades monetárias na aplicação das políticas de contenção da inflação, seguindo os mandamentos do regime de metas, esta tem se mostrado resistente, provocando um debate em torno de fatores que podem estar ocasionando tal comportamento. Na literatura internacional, alguns trabalhos têm creditado aos choques de oferta, especialmente aos desencadeados pela variação dos preços das commodities, uma participação significativa na inflação, principalmente em economias onde os produtos primários figuram como maioria na pauta exportadora. Na literatura nacional, já existem alguns trabalhos que apontam nesta mesma direção. Sendo assim, buscou-se, como objetivo principal para o presente estudo, avaliar como os choques de oferta, mais especificamente os choques originados pelos preços das commodities, têm impactado na inflação brasileira e como e com que eficiência a política monetária do país tem reagido. Para tanto, foi estimado um modelo semiestrutural contendo uma curva de Phillips, uma curva IS e duas versões da Função de Reação do Banco Central, de modo a verificar como as decisões de política monetária são tomadas. O método de estimação empregado foi o de Autorregressão Vetorial com Correção de Erro (VEC) na sua versão estrutural, que permite uma avaliação dinâmica das relações de interdependência entre as variáveis do modelo proposto. Por meio da estimação da curva de Phillips foi possível observar que os choques de oferta, tanto das commodities como da produtividade do trabalho e do câmbio, não impactam a inflação imediatamente, porém sua relevância é crescente ao longo do tempo chegando a prevalecer sobre o efeito autorregressivo (indexação) verificado. Estes choques também se apresentaram importantes para o comportamento da expectativa de inflação, produzindo assim, uma indicação de que seus impactos tendem a se espalhar pelos demais setores da economia. Através dos resultados da curva IS constatou-se a forte inter-relação entre o hiato do produto e a taxa de juros, o que indica que a política monetária, por meio da fixação de tal taxa, influencia fortemente a demanda agregada. Já por meio da estimação da primeira função de reação, foi possível perceber que há uma relação contemporânea relevante entre o desvio da expectativa de inflação em relação à meta e a taxa Selic, ao passo que a relação contemporânea do hiato do produto sobre a taxa Selic se mostrou pequena. Por fim, os resultados obtidos com a segunda função de reação, confirmaram que as autoridades monetárias reagem mais fortemente aos sinais inflacionários da economia do que às movimentações que acontecem na atividade econômica e mostraram que uma elevação nos preços das commodities, em si, não provoca diretamente um aumento na taxa básica de juros da economia.

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This paper empirically investigates the extent to which the European Central Bank has responded to evolving economic conditions in its member states as opposed to the euro area as a whole. Based on a forward-looking Taylor rule-type policy reaction function, we conduct counterfactual exercises that compare the monetary policy behavior of the ECB with two alternative hypothetical scenarios: (1) were the euro member states to make individual policy decisions, and (2) were the ECB to respond to the economic conditions of individual members. The results reflect the extent of heterogeneity among the national economies in the monetary union and indicate that the ECB's monetary policy rates have been particularly close to the "counterfactual" interest rates of its largest euro members, as well as of countries with similar economic conditions, which includes Germany, Austria, Belgium and France.

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Az alsó kamatkorlát melletti előretekintő iránymutatás a kamatpolitika helyettesítője, a várakozások és a pénzpiaci hozamok befolyásolásának nem konvencionális monetáris politikai eszköze. A jegybank a piaci szereplők számára előre jelezheti az alacsony kamatkörnyezet tartós fennmaradását (delphoi típus), és kötelezettséget is vállalhat erre (odüsszeuszi típus). Ez utóbbi esetben megváltozik a jegybanki reakciófüggvény: a jegybanki kamatdöntésekben nem az inflációs kilátások és az inflációs cél közötti eltérés, illetve a kibocsátási rés jut kitüntetett szerephez, hanem valamilyen állapotváltozó alakulása vagy az időtényező. A reakciófüggvény változásának hitelessége esetén a hozamok csökkenésére lehet számítani. Ha a jegybank a kamatszint fenntartásának feltételéül az állapotváltozók olyan értékeit jelöli meg, amelyek teljesülése esetén az inflációs célkövetés szabályai szerint amúgy sem emelt volna kamatot, akkor az előretekintő iránymutatás „üres beszéd”, és a hozamokra gyakorolt hatás is elmaradhat. Egyelőre nem eldönthető, hogy az előretekintő iránymutatás a kamatpolitika átmeneti helyettesítőjéből annak tartós kiegészítő elemévé válik-e. _____ Forward guidance is a substitute for interest-rate policy where the zero lower boundary applies. It is an unconventional monetary policy instrument intended to influence market yields and expectations. The central bank may give signals (forecasts) to the market on lasting maintenance of a low interest-rate environment (Delphi type) or may commit itself to do so (Odysseus type). In the latter case the reaction function changes: instead of inflation prospects and output gap, the main role in central bank rate decisions becomes the evolution of given macroeconomic state variables or the time factor. If changes of the reaction function are credible, a drop in security yields are expected. Forward guidance is just cheap talk if such values in economic state variables are set as conditions for keeping interest rates unchanged, which based on the rules of inflation targeting would not trigger an interest rate increase, regardless. In that case, no impact on yields may occur. For the time being it cannot be decided whether forward guidance is transitory or a lasting instrument of monetary policy.

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We explore the equilibrium properties of two types of "difference-form" persuasion contest functions derived in Skaperdas and Vaidya in which contestants spend resources to persuade an audience. We find that both types of functions generate interior pure strategy Nash equilibria unlike Baik and Che and Gale with characteristics different to existing literature. For one type of function, we find that the reaction function of each player is "flat" and nonresponsive to the level of resources devoted by the rival so that the "preemption effect" as defined by Che and Gale is absent. Further, the equilibrium is invariant to the sequencing of moves. For the second type of function, which applies when there is asymmetry among contestants with regard to the quality of evidence, we find that the reaction functions of the stronger and weaker players have gradients with opposite signs relative to Dixit and therefore their incentive to precommit expenditures in a sequential move game is also different. For both types of functions, the extent of rent dissipation is partial. From the equilibrium analysis, we are also able to establish the potential effects of some specific factors affecting persuasion such as evidence potency, the degree of truth, and bias on aggregate resource expenditures and welfare.

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This series of experiments investigated the role of a prefrontal cortical-dorsal striatal circuit in attention, using a continuous performance task of sustained and spatially divided visual attention. A unilateral excitotoxic lesion of the medial prefrontal cortex and a contralateral lesion of the medial caudate-putamen were used to "disconnect" the circuit. Control groups of rats with unilateral lesions of either structure were tested in the same task. Behavioral controls included testing the effects of the disconnection lesion on Pavlovian discriminated approach behavior. The disconnection lesion produced a significant reduction in the accuracy of performance in the attentional task but did not impair Pavlovian approach behavior or affect locomotor or motivational variables, providing evidence for the involvement of this medial prefrontal corticostriatal system in aspects of visual attentional function.

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The x-ray crystallographic structure of the photosynthetic reaction center (RC) has proven critical in understanding biological electron transfer processes. By contrast, understanding of intraprotein proton transfer is easily lost in the immense richness of the details. In the RC of Rhodobacter (Rb.) sphaeroides, the secondary quinone (QB) is surrounded by amino acid residues of the L subunit and some buried water molecules, with M- and H-subunit residues also close by. The effects of site-directed mutagenesis upon RC turnover and quinone function have implicated several L-subunit residues in proton delivery to QB, although some species differences exist. In wild-type Rb. sphaeroides, Glu L212 and Asp L213 represent an inner shell of residues of particular importance in proton transfer to QB. Asp L213 is crucial for delivery of the first proton, coupled to transfer of the second electron, while Glu L212, possibly together with Asp L213, is necessary for delivery of the second proton, after the second electron transfer. We report here the first study, by site-directed mutagenesis, of the role of the H subunit in QB function. Glu H173, one of a cluster of strongly interacting residues near QB, including Asp L213, was altered to Gln. In isolated mutant RCs, the kinetics of the first electron transfer, leading to formation of the semiquinone, QB-, and the proton-linked second electron transfer, leading to the formation of fully reduced quinol, were both greatly retarded, as observed previously in the Asp L213 --> Asn mutant. However, the first electron transfer equilibrium, QA-QB <==> QAQB-, was decreased, which is opposite to the effect of the Asp L213 --> Asn mutation. These major disruptions of events coupled to proton delivery to QB were largely reversed by the addition of azide (N3-). The results support a major role for electrostatic interactions between charged groups in determining the protonation state of certain entities, thereby controlling the rate of the second electron transfer. It is suggested that the essential electrostatic effect may be to "potentiate" proton transfer activity by raising the pK of functional entities that actually transfer protons in a coupled fashion with the second electron transfer. Candidates include buried water (H3O+) and Ser L223 (serine-OH2+), which is very close to the O5 carbonyl of the quinone.

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The single spin asymmetry, ALT ′, and the polarized structure function, σ LT′, for the p( e&ar; , e′K +)Λ reaction in the resonance region have been measured and extracted using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. Data were taken at an electron beam energy of 2.567 GeV. The large acceptance of CLAS allows for full azimuthal angle coverage over a large range of center-of-mass scattering angles. Results were obtained that span a range in Q 2 from 0.5 to 1.3 GeV2 and W from threshold up to 2.1 GeV and were compared to existing theoretical calculations. The polarized structure function is sensitive to the interferences between various resonant amplitudes, as well as to resonant and non-resonant amplitudes. This measurement is essential for understanding the structure of nucleons and searching for previously undetected nucleon excited states (resonances) predicted by quark models. The W dependence of the σ LT′ in the kinematic regions dominated by s and u channel exchange (cos qcmk = −0.50, −0.167, 0.167) indicated possible resonance structures not predicted by theoretical calculations. The σLT ′ behavior around W = 1.875 GeV could be the signature of a resonance predicted by the quark models and possibly seen in photoproduction. In the very forward angles where the reaction is dominated by the t-channel, the average σLT ′ was zero. There was no indication of the interference between resonances or resonant and non-resonant amplitudes. This might be indicating the dominance of a single t-channel exchange. Study of the sensitivity of the fifth structure function data to the resonance around 1900 MeV showed that these data were highly sensitive to the various assumptions of the models for the quantum number of this resonance. This project was part of a larger CLAS program to measure cross sections and polarization observables for kaon electroproduction in the nucleon resonance region. ^

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BACKGROUND: Although we know much about the molecular makeup of the sinus node (SN) in small mammals, little is known about it in humans. The aims of the present study were to investigate the expression of ion channels in the human SN and to use the data to predict electrical activity. METHODS AND RESULTS: Quantitative polymerase chain reaction, in situ hybridization, and immunofluorescence were used to analyze 6 human tissue samples. Messenger RNA (mRNA) for 120 ion channels (and some related proteins) was measured in the SN, a novel paranodal area, and the right atrium (RA). The results showed, for example, that in the SN compared with the RA, there was a lower expression of Na(v)1.5, K(v)4.3, K(v)1.5, ERG, K(ir)2.1, K(ir)6.2, RyR2, SERCA2a, Cx40, and Cx43 mRNAs but a higher expression of Ca(v)1.3, Ca(v)3.1, HCN1, and HCN4 mRNAs. The expression pattern of many ion channels in the paranodal area was intermediate between that of the SN and RA; however, compared with the SN and RA, the paranodal area showed greater expression of K(v)4.2, K(ir)6.1, TASK1, SK2, and MiRP2. Expression of ion channel proteins was in agreement with expression of the corresponding mRNAs. The levels of mRNA in the SN, as a percentage of those in the RA, were used to estimate conductances of key ionic currents as a percentage of those in a mathematical model of human atrial action potential. The resulting SN model successfully produced pacemaking. CONCLUSIONS: Ion channels show a complex and heterogeneous pattern of expression in the SN, paranodal area, and RA in humans, and the expression pattern is appropriate to explain pacemaking.

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In this paper, we consider the following non-linear fractional reaction–subdiffusion process (NFR-SubDP): Formula where f(u, x, t) is a linear function of u, the function g(u, x, t) satisfies the Lipschitz condition and 0Dt1–{gamma} is the Riemann–Liouville time fractional partial derivative of order 1 – {gamma}. We propose a new computationally efficient numerical technique to simulate the process. Firstly, the NFR-SubDP is decoupled, which is equivalent to solving a non-linear fractional reaction–subdiffusion equation (NFR-SubDE). Secondly, we propose an implicit numerical method to approximate the NFR-SubDE. Thirdly, the stability and convergence of the method are discussed using a new energy method. Finally, some numerical examples are presented to show the application of the present technique. This method and supporting theoretical results can also be applied to fractional integrodifferential equations.