1000 resultados para Expected shortfall (ES)
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This paper studies the impact of instrumental voting on information demand and mass media behaviour during electoral campaigns. If voters act instrumentally then information demand should increase with the closeness of an election. Mass media are modeled as profit-maximizing firms that take into account information demand, the value of customers to advertisers and the marginal cost of customers. Information supply should be larger in electoral constituencies where the contest is expected to be closer, there is a higher population density, and customers are on average more profitable for advertisers. The impact of electorate size is theoretically undetermined. These conclusions are then tested with comfortable results on data from the 1997 general election in Britain.
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It is often argued that even if optimal ex-post, settlement dilutes deterrence ex-ante. We analyze the interest for the tax authority of committing, ex-ante, to a settlement strategy. We show that to commit to the use of settlements is ex-ante optimal when the tax authority receives signals that provide statistical information about the taxpayers' true tax liability. The more informative the signal, the larger the additional expected evenue raised by the tax authority when using settlement as a policy tool.
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We study the incentives of candidates to enter or to exit elections in order to strategically affect the outcome of a voting correspondence. We extend the results of Dutta, Jackson and Le Breton (2000), who only considered single-valued voting procedures by admitting that the outcomes of voting may consist of sets of candidates. We show that, if candidates form their preferences over sets according to Expected Utility Theory and Bayesian updating, every unanimous and non dictatorial voting correspondence violates candidate stability. When candidates are restricted to use even chance prior distributions, only dictatorial or bidictatorial rules are unanimous and candidate stable. We also analyze the implications of using other extension criteria to define candidate stability that open the door to positive results.
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La Región Metropolitana de Barcelona (RMB) ha sido caracterizada como un sistema urbano policéntrico. Sin embargo, no existe un criterio comúnmente aceptado que haya permitido identificar con claridad los subcentros de la región. La investigación que aquí se presenta persigue un doble objetivo: en primer lugar identificar los subcentros de empleo de la RMB mediante un método objetivo y, en segundo lugar, valorar su grado de policentrismo. Para identificar los subcentros se procede siguiendo dos pasos: primero se identifican los municipios candidatos a subcentro utilizando criterios basados en la densidad de empleo y en el índice Empleos/Población, para a continuación estimar una función de densidad de población utilizando como variables explicativas, además de la distancia al CBD, la distancia a cada uno de los candidatos a subcentro. Los municipios identificados mediante este doble filtro sólo capturan un porcentaje relativamente reducido del total de puestos de trabajo debido a que elnúcleo ampliado (Barcelona más continuo urbano) concentra un porcentaje de empleos muy significativo, y a que el ratio Empleos/Población presenta unos valores muy homogéneos en todos los municipios con independencia de su tamaño.
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This paper analyzes the different compositions of the catalan governing coalitions during the current democratic period, and offers some predictions about the coalitions that can be expected in the future. During this period, in catalan politics, there have been two main political issues over which the different parties have taken positions: rightist versus leftist with respect to economic policy, and sovereign versus centralist with respect to the power distribution within the state. I find that for any allocation of parliament seats there is a key party: a party that has a clear advantage in terms of being able to decide the composition of the governing coalition. I show the features that allow a party to become the key party and those that affect the size of the advantage of the key party.
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The purpose of this paper is to analyze the effect of multimarket contact on the behavior of pharmaceutical firms controlling for different levels of regulatory constraints using IMS MIDAS database. Theoretically, firms that meet in several markets are expected to be capable of sustaining implicitly more profitable out- comes, even if perfect monitoring is not possible. Firms may find it profitable to redistribute their market power among markets where they are operating. We present evidence for nine OECD countries with different degrees of regulation and show that regulation affects the importance of economic forces on firms' price setting behavior. Furthermore, our results confirms the presence of the predictions of the multimarket theory for more market friendly countries (U.S. and Canada) and less regulated ones (U.K., Germany, Netherlands), in contrast, for highly regulated countries (Japan, France, Italy and Spain) the results are less clear with some countries being
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Estudi elaborat a partir d’una estada al Paul Scherrer Institut del Maig a l’Octubre del 2006 amb l’ajuda i supervisió dels Dr. Konstantins Jefimovs i Dr. Christian David. Focalitzar raigs X tous és una necessitat essencial per al microanàlisis, la microscopia, i fer imatges en moltes Instal·lacions de Radiació Sincrotró. Les Lents Zonals de Fresnel (FZP, de la denominació anglesa “Fresnel Zone Plates”) han demostrat donar uns punts focals amb una resolució espacial destacada i una baixa il·luminació de fons. Tanmateix, la fabricació de FZP és complexa i no totalment reproduïble. A més a més, el temps de vida de les FZP és força curt, ja que estant situades sobre membranes de nitrur de silici molt fines i altament absorbents. Per tant, hem fet esforços per implementar FZP de silici, que s’espera que siguin més resistents. L’element està fet d’una oblia de cristall de silici poc absorbent, i no presenta cap interfase entre materials. Així doncs, aquestes lents són especialment adequades per a aguantar les extremes càrregues de radiació de les fonts de raigs X més brillants. Particularment, això és molt important per a les aplicacions a les pròximes generacions de fonts de raigs X, com els Làsers d’Electrons Lliures (FEL, de la denominació anglesa “Free Electron Laser”). El silici també garanteix que no hi hagi cap banda d’absorció en el rang d’energies de la finestra de l’aigua (200-520 eV), fent aquestes lents ideals per a fer imatges de mostres biològiques. En aquest informe, hi ha una descripció detallada de tots els passos involucrats en la fabricació de les Lents Zonals de Fresnel de silici. En resum, les estructures de FZP es modelen sobre una resina utilitzant litografia per feix d’electrons i llavors el patró es transmet al silici mitjançant un gravat d’ions reactius (RIE, de la denominació anglesa ‘Reactive Ion Etching’) utilitzant una fina (20 nm) màscara de Crintermitja. Les membranes de silici es poden aprimar després de la fabricació de les estructures per a garantir una transmissió suficient fins i tot a baixes energies. Aquest informe també inclou l’anàlisi i la discussió d’alguns experiments preliminars per avaluar el rendiment de les Si FZPs fets a la línia de llum PolLux del Swiss Ligth Source amb l’ajuda dels Dr. Jörg Raabe i Dr. George Tzvetkov.
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By staining females of Anopheles cruzi with fluorescent coloured powders in a forest in the State of Santa Catarina, we showed that they move from canopy to ground and vice-versa to feed. This suggests that in areas where this mosquito is a vector of human and simian malarias sporadic infections of man with monkey plasmodia might be expected.
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El presente trabajo pretende implantar un proyecto de formación ambiental y, a la vez, crear el marco físico y social para que así sea. De esta forma, se darán a conocer y mejorarán los conocimientos ambientales en la población del municipio de Concepción Las Minas, con el fin de que puedan mejorar sus técnicas a la hora de gestionar su territorio y, a la vez, ampliar sus conocimientos ambientales, útiles en el campo de la educación. Para realizar estas capacitaciones fue necesaria una descripción del territorio junto con un análisis de las principales problemáticas ambientales municipales. Se realizaron sondeos a la población para valorar su nivel de conocimientos ambientales. Con toda la información recogida, se planificaron una serie de sesiones formativas destinadas a maestros, niños y técnicos ambientales. Las sesiones trataban de formar y a la vez concienciar sobre temas generadores tales como el recurso hídrico, forestal, gestión de residuos, etc. Estas capacitaciones se dieron tanto a nivel teórico como a nivel práctico. La valoración global de las capacitaciones es positiva. Cabe destacar un alto grado de participación por parte de los maestros y los alumnos de las escuelas municipales, mostrando una gran implicación en las distintas sesiones. Contrariamente, no se obtuvo el mismo resultado con el colectivo de técnicos municipales, ya que faltó tiempo y planificación.
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Economic development goes hand in hand with an increase in the consumption of natural resources. Some analysts use material flows to describe such relationship [Eurostat 2001, Weisz et al., 2006], or exergy [Ayres et al., 2003]. Instead this paper will use a characterisation of the exosomatic energy metabolism based on expected benchmark values to describe possible constraints to economic development posed by available human time and energy. The aim of the paper is to identify types of exosomatic energy metabolism of different societies to interpret its consequences for economic development. This is done with the application of the accounting methodology called Multi-Scale Integrated Analysis of Societal Metabolism (MSIASM) to the particular case of energy metabolism for the analysis of the economies of Brazil, Chile and Venezuela.
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One of the main implications of the efficient market hypothesis (EMH) is that expected future returns on financial assets are not predictable if investors are risk neutral. In this paper we argue that financial time series offer more information than that this hypothesis seems to supply. In particular we postulate that runs of very large returns can be predictable for small time periods. In order to prove this we propose a TAR(3,1)-GARCH(1,1) model that is able to describe two different types of extreme events: a first type generated by large uncertainty regimes where runs of extremes are not predictable and a second type where extremes come from isolated dread/joy events. This model is new in the literature in nonlinear processes. Its novelty resides on two features of the model that make it different from previous TAR methodologies. The regimes are motivated by the occurrence of extreme values and the threshold variable is defined by the shock affecting the process in the preceding period. In this way this model is able to uncover dependence and clustering of extremes in high as well as in low volatility periods. This model is tested with data from General Motors stocks prices corresponding to two crises that had a substantial impact in financial markets worldwide; the Black Monday of October 1987 and September 11th, 2001. By analyzing the periods around these crises we find evidence of statistical significance of our model and thereby of predictability of extremes for September 11th but not for Black Monday. These findings support the hypotheses of a big negative event producing runs of negative returns in the first case, and of the burst of a worldwide stock market bubble in the second example. JEL classification: C12; C15; C22; C51 Keywords and Phrases: asymmetries, crises, extreme values, hypothesis testing, leverage effect, nonlinearities, threshold models
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Aquest és un projecte que tracta sobre la indexació automàtica de continguts televisius. És una tasca que guanyarà importància amb els imminents canvis que hi haurà en la televisió que coneixem. L'entrada de la nova televisió digital farà que hi hagi una interacció molt més fluida entre l'espectador i la cadena, a més de grans quantitats de canals, cada un amb programes de tipus totalment diferents. Tot això farà que tenir mètodes de cerca basats en els continguts d'aquests programes sigui del tot imprescindible. Així doncs, el nostre projecte està basat plenament en poder extreure alguns d'aquests descriptors que faran possible la categorització dels diferents programes televisius.
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Aquest article presenta els resultats d'una enquesta Delphi internacional i interdisciplinària sobre el desenvolupament futur de les revistes electròniques. El quadre d'experts constà de 45 científics, editors, bibliotecaris, agents de revistes i consultors. L'enquesta cobria cinc àrees d'interès sobre revistes electròniques: el futur rol de la literatura erudita en suport revista, escenaris per a les revistes del futur; crisi en les publicacions en sèrie; arxiu de revistes electròniques i nous models en l'adquisició i l'accés. L'enquesta Delphi va estudiar els canvis esperats durant els propers cinc a deu anys. Els resultats són analitzats i indiquen que, durant els seus 300 anys d'història, les revistes mai no han afrontat tants de canvis com els que experimenten ara, o els que s'esperen durant els propers cinc a deu anys.
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The purpose of this paper is to provide new evidence on the issue of the effect on public enterprises economic performance of the introduction of some given changes in organisational status and management practices, while keeping the enterprises under public control. Our approach is case study type and relies on comparative efficiency literature. We identify relevant changes on the organisational status of a State owned large hotel group along a period of twenty years, next we measure its annual efficiency indicators, and then evaluate to which extent the observed changes in economic performance can be attributable to the corresponding management reforms carried out. As a result we find that the formally more relevant change in organisational status (the enterprise passing to be a Limited Company), which implied a substantial increase in the enterprise autonomy, did not produce a significant improvement in its economic performance; a finding contrary to what we expected according to agency theory. However, a second relevant organisational change –five years later- when both the principal (government) and the agent (firm’s CEO) changed is consistently related to a significant improvement in economic performance. As a research implication we abide for use more precise agency theory statements; and as a practical implication we argue here that potentialities of improvement brought about by a formal-legal change in the status of the enterprise may require also –in order to actually improve firm’s efficiency- some changes in the firm’s key personal positions: supervisor (principal) and CEO (agent), in the sense that a change to a greater-autonomy for the enterprise it seems should come together a parallel new ‘management culture’. Practical implications Management good practises to apply to other public enterprise’s restructuring in order to improve their efficiency. It’s the first study on organizational changes and efficiency for an important Spanish public enterprise.
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A growing literature integrates theories of debt management into models of optimal fiscal policy. One promising theory argues that the composition of government debt should be chosen so that fluctuations in the market value of debt offset changes in expected future deficits. This complete market approach to debt management is valid even when the government only issues non-contingent bonds. A number of authors conclude from this approach that governments should issue long term debt and invest in short term assets. We argue that the conclusions of this approach are too fragile to serve as a basis for policy recommendations. This is because bonds at different maturities have highly correlated returns, causing the determination of the optimal portfolio to be ill-conditioned. To make this point concrete we examine the implications of this approach to debt management in various models, both analytically and using numerical methods calibrated to the US economy. We find the complete market approach recommends asset positions which are huge multiples of GDP. Introducing persistent shocks or capital accumulation only worsens this problem. Increasing the volatility of interest rates through habits partly reduces the size of these simulations we find no presumption that governments should issue long term debt ? policy recommendations can be easily reversed through small perturbations in the specification of shocks or small variations in the maturity of bonds issued. We further extend the literature by removing the assumption that governments every period costlessly repurchase all outstanding debt. This exacerbates the size of the required positions, worsens their volatility and in some cases produces instability in debt holdings. We conclude that it is very difficult to insulate fiscal policy from shocks by using the complete markets approach to debt management. Given the limited variability of the yield curve using maturities is a poor way to substitute for state contingent debt. The result is the positions recommended by this approach conflict with a number of features that we believe are important in making bond markets incomplete e.g allowing for transaction costs, liquidity effects, etc.. Until these features are all fully incorporated we remain in search of a theory of debt management capable of providing robust policy insights.