871 research outputs found
The “Great Moderation” and the Monetary Transmission Mechanism in Chile
This paper analyzes the significant reduction in the volatility of output growth and inflation seen in the Chilean economy in the present decade. This reduced volatility, sometimes called the “great moderation,” coincides with several important changes to the Chilean macroeconomic framework, including the establishment of a full-fledged inflation targeting regime for monetary policy and a rule based on a target for the structural fiscal surplus. The paper examines the impact of these changes on the monetary transmission mechanism and explores how the “great moderation” has been affected by economic shocks and by the endogenous response of policy as reflected in the monetary transmission mechanism. The paper also reports results of a monetary vector autoregression model that finds important changes in the way shocks are transmitted to the Chilean economy.
Why do we smile? On the determinants of the implied volatility function.
We report simple regressions and Granger causality tests in order to understand the pattern of implied volatilities across exercise prices. We employ all calls and puts transacted between 16:00 and 16:45 on the Spanish IBEX-35 index from January 1994 to April 1996. Transaction costs, proxied by the bid–ask spread, seem to be a key determinant of the curvature of the volatility smile. Moreover, time to expiration, the uncertainty associated with the market and the relative market momentum are also important variables in explaining the smile.Smiles; Bid–ask spread; Volatility; Causality;
Smiles, Bid-ask Spreads and Option pricing.
Given the evidence provided by Longstaff (1995), and Peña, Rubio and Serna (1999) a serious candidate to explain the pronounced pattern of volatility estimates across exercise prices might be related to liquidity costs. Using all calls and puts transacted between 16:00 and 16:45 on the Spanish IBEX‐35 index futures from January 1994 to October 1998 we extend previous papers to study the influence of liquidity costs, as proxied by the relative bid‐ask spread, on the pricing of options. Surprisingly, alternative parametric option pricing models incorporating the bid‐ask spread seem to perform poorly relative to Black‐Scholes.smiles; bid-ask spread; implied volatility function; option pricing;
El paisaje urbano histórico de la "Ciudad Vieja" de Salamanca, claves para un plan de gestión
El Plan de Gestión de la Ciudad Vieja de Salamanca, encargado por la Junta de Castilla y León, responde a las recientes directivas de la Organización de las Naciones Unidas para la Educación, la Ciencia y la Cultura -UNESCO- que buscan introducir nuevas herramientas de gestión adaptadas a las condiciones singulares de cada caso. Sin embargo la experiencia sobre estos planes es casi inexistente. En este contexto el plan orienta su objetivo principal, proteger y poner en valor con eficacia el "valor universal excepcional" que justifica la inclusión de Salamanca en la lista de Patrimonio Mundial, con un desarrollo novedoso del concepto de "paisaje urbano histórico", enfocado desde tres perspectivas: el territorio, el paisaje interior de la ciudad y el paisaje intangible. Este escrito enuncia los contenidos principales de dicho documento en proceso de aprobación y que incluye la revisión del Plan Especial del Conjunto Histórico. Pero, sobre todo, se centra en mostrar un modelo abierto de comprensión espacial de los elementos que componen el patrimonio urbano, modelo que fundamenta y dirige los criterios de conservación activa aplicables.The Management Plan for the Old City of Salamanca, assigned by the Castilla y León Government, is the result of the current UNESCO directives oriented to introduce new management tools fitted for any case. However practically does not exist experience. In this context the plan guides its main scope, the efficiency in the "outstanding universal value" protection and revalorization for justifying the Salamanca inclusion in the World List, with an innovative development of the "historical urban landscape" concept. This is focused from three perspectives: the territory, the inner city landscape and the intangible landscape. This paper explains the elements of the proposal -now involved in its approval process-, the Management Plan and the plan for the Urban Conservation Area included in it. But, over all, this paper shows an open model for understanding the urban heritage components, model which is in the basis of the improvement principles applied
New design parameters for biparabolic beach profiles (SW Cadiz, Spain)
165 profiles of seventy-one beaches along the Gulf of Cadiz (SW, Spain) were studied to improve the formulation of the beach profile in tidal seas. Maritime climate, degree of energy exposure and size of the sand grains were taken into account to study the two sections of the biparabolic profile. The objective of the study was the determination of more accurate formulations of the design parameters for the equilibrium profile that involves tidal seas. These formulations were modelled and validated based on existing profiles to quantify the error existing between the real profile and the modelling. This comparative analysis was extended by considering the formulations proposed by other authors. The best results were obtained with the proposal presented herein
Congenital Pulmonary Sequestration Supplied by the Right Coronary Artery
A 67-year-old patient, with no respiratory symptoms, underwent coronary catheterization for revascularization of stenosis in the right coronary artery, during which we observed a large caliber artery, apparently bronchial, extending toward the left lung base..
Why do we smile? On the determinants of the implied volatility function
We report simple regressions and Granger causality tests in order to understand the pattern of implied volatilities across exercise prices. We employ all calls and puts transacted between 16:00 and 16:45 on the Spanish IBEX-35 index from January 1994 to April 1996. Transaction costs, proxied by the bid–ask spread, seem to be a key determinant of the curvature of the volatility smile. Moreover, time to expiration, the uncertainty associated with the market and the relative market momentum are also important variables in explaining the smile.Publicad
A Design Parameter for Reef Beach Profiles—A Methodology Applied to Cadiz, Spain
The southwestern coast of Spain is in a tidal zone (mesotidal) which causes the equilibrium profile to be developed in two different sections: the breakage section and the swash section. These two sections give rise to the typical bi-parabolic profile existing in tidal seas. The existence of areas with reefs/rocks which interrupt the normal development of the typical bi-parabolic profile causes different types of beach profiles. The objective of this article is designing an easy methodology for determining new formulations for the design parameters of the equilibrium profile of beaches with reefs in tidal seas. These formulations are applied on 16 profiles to quantify the error between the real profile data and the modelling results. A comparative analysis is extended to the formulations proposed by other authors, from which it is found that better results are obtained with the new formulations
- …