COMPUTING ROBUST STYLIZED FACTS ON COMOVEMENT

We propose an alternative method of obtaining stylized facts on comovement, based on the cross-correlation function of the prewhitened time series, which only depends on the purely stochastic components of the series and the cross efects between them. This approach has the property of being robust to the filtering procedure and hence to the cicle definition. The usual approach consists of obtaining the cross-correlation function of filtered variables, which reflect a mixture of both the existing cross-correlation between the variables and the autocorrelation structure of each of them. The autocorrelation structure, in turn, crucially depends on the filtering procedure. The relevance of such an approach is tested by revisiting some of the facts reported by Kydland and Prescott (1990).Prewhitening, Business Cycle, Stylized Facts, Comovement.

Retirement incentives, individual heterogeneity and labour transitions of employed and unemployed workers

In this paper we analyze the sensitivity of the labour market decisions of workers close to retirement with respect to the incentives created by public regulations. We improve upon the extensive prior literature on the effect of pension incentives on retirement in two ways. First, by modeling the transitions between employment, unemployment and retirement in a simultaneous manner, paying special attention to the transition from unemployment to retirement (which is particularly important in Spain). Second, by considering the influence of unobserved heterogeneity in the estimation of the effect of our (carefully constructed) incentive variables. Using administrative data, we find that, when properly defined, economic incentives have a strong impact on labour market decisions in Spain. Unemployment regulations are shown to be particularly influential for retirement behaviour, along with the more traditional determinants linked to the pension system. Pension variables also have a major bearing on both workers’ reemployment decisions and on the strategic actions of employers. The quantitative impact of the incentives, however, is greatly affected by the existence of unobserved heterogeneity among workers. Its omission leads to sizable biases in the assessment of the sensitivity to economic incentives, a finding that has clear consequences for the credibility of any model-based policy analysis. We confirm the importance of this potential problem in one especially interesting instance: the reform of early retirement provisions undertaken in Spain in 2002. We use a difference-in-difference approach to measure the behavioural reaction to this change, finding a large overestimation when unobserved heterogeneity is not taken into account.Retirement, unemployment, incentives, Pension system, Unobserved, heterogeneity, Spain.

Social Security and the search behaviour of workers approaching retirement

This paper explores the links between unemployment, retirement and their associated public insurance programs. It is a contribution to a growing body of literature focused on a better understanding of the labor behavior of advanced-age workers, which has gained importance as the pension crisis looms. It also contributes to the literature of optimal unemployment insurance by exploring the interaction of unemployment benefits and retirement pensions. The analysis combines the development of a new theoretical model and a detailed exploration of the empirical regularities using the Spanish Muestra Continua de Vidas Laborales (MCVL) dataset. The model is an extension of the standard search model, designed to reproduce the non-stationary environment faced by workers of advanced ages (in the age range 50/65). Via calibrated simulations we show that the basic empirical re-employment and retirement patterns can be considered as rational responses to both the labor market conditions and the institutional incentives. Generous Unemployment Benefits (for durations of up to two years) together with very significant early retirement penalties, make optimal to stay unemployed without searching for large groups of unemployed workers. This moral hazard problem can be substantially alleviated through institutional reform. We explore several potential reforms and find that changing the details of early retirement pensions seems more promising than changing the Unemployment Benefit system.Unemployment, Retirement, Search models

The effects of employment uncertainty and wealth shocks on the labor supply and claiming behavior of older American workers

Unemployment rates in developed countries have recently reached levels not seen in a generation, and workers of all ages are facing increasing probabilities of losing their jobs and considerable losses in accumulated assets. These events likely increase the reliance that most older workers will have on public social insurance programs, exactly at a time that public finances are suffering from a large drop in contributions. Our paper explicitly accounts for employment uncertainty and unexpected wealth shocks, something that has been relatively overlooked in the literature, but that has grown in importance in recent years. Using administrative and household level data we empirically characterize a life-cycle model of retirement and claiming decisions in terms of the employment, wage, health, and mortality uncertainty faced by individuals. Our benchmark model explains with great accuracy the strikingly high proportion of individuals who claim benefits exactly at the Early Retirement Age, while still explaining the increased claiming hazard at the Normal Retirement Age. We also discuss some policy experiments and their interplay with employment uncertainty. Additionally, we analyze the effects of negative wealth shocks on the labor supply and claiming decisions of older Americans. Our results can explain why early claiming has remained very high in the last years even as the early retirement penalties have increased substantially compared with previous periods, and why labor force participation has remained quite high for older workers even in the midst of the worse employment crisis in decades.employment uncertainty, wealth shocks, retirement, labor supply, life-cycle models

LA CONSTRUCCIÓN DE LA ARQUITECTURA ORGANIZATIVA EN LAS ENTIDADES SIN FINES DE LUCRO. EL CASO DE LAS ONGD EN ESPAÑA

RESUMENEl objetivo del presente trabajo es valorar el equilibrio de las fuerzas organizativas en la construcción de una arquitectura organizativa eficiente y, todo ello, bajo un enfoque de agencia. Los resultados del análisis empírico, llevado a cabo en las más importantes ONGD españolas durante el año 2003, ponen de relieve la gran importancia de la influencia mutua de la delegación de derechos de decisión, sistemas de incentivos y el uso de medidas de evaluación del rendimiento en el logro del equilibrio organizativo, lo que nos permite afirmar que, para el caso estudiado, la teoría se confirma.ABSTRACTThe aim of this paper is to evaluate the balance of organizational components in the design of an efficient organizational architecture from an agency perspective. The results of the empirical analysis, performed in the most prominent Spanish NGDO throughout the year 2003, show the great importance of the mutual influence among the delegation of decision rights, the incentive systems and the use of performance measurements in the achievement of organizational equilibrium

A Practical Example for Model-Driven Web Requirements

The number of approaches for Web environments has grown very fast in the last years: HDM, OOHDM, and WSDM were among the first, and now a large number can be found in the literature. With the definition of MDA (Model- Driven Architecture) and the acceptance of MDE (Model-Driven Engineering) techniques in this environment, some groups are working in the use of metamodels and transformations to make their approaches more powerful. UWE (UMLBased Web Engineering) or OOWS (Object-Oriented Web Solutions) are only some examples. However, there are few real experiences with Web Engineering in the enterprise environment, and very few real applications of metamodels and MDE techniques. In this chapter the practical experience of a Web Engineering approach, NDT, in a big project developed in Andalusia is presented. Besides, it shows the usability of metamodels in real environments

Effect of long range spatial correlations on the lifetime statistics of an emitter in a two-dimensional disordered lattice

The effect of spatial correlations on the Purcell effect in a bidimensional dispersion of resonant nanoparticles is analyzed. We perform extensive calculations on the fluorescence decay rate of a point emitter embedded in a system of nanoparticles statistically distributed according to a simple 2D lattice-gas model near the critical point. For short-range correlations (high temperature thermalization) the Purcell factors present a long-tailed statistic which evolves towards a bimodal distribution when approaching the critical point where the spatial correlation length diverges. Our results suggest long-range correlations as a possible origin of the large fluctuations of experimental decay rates in disordered metal films.Comment: 6 pages, 5 figure

Quality of Life in Spanish Patients with Liver Transplant

Background: Liver transplantation is the optimal method of treatment in patients with end-stage liver failure. Transplantation medicine has significantly progressed in the last time, but some psychology and psychosomatic problems still remain unsolved. Health-Related Quality of Life (HRQL) in liver transplant is considered a useful measure of evolutionary process of the illness. Objective: The authors analyzed the evolution of HRQL in pre-transplant (waiting-list patients) and post-transplant (first year after liver transplant) periods of liver transplant Spanish patients. Methods: A prospective and longitudinal study was carried out among patients who received a liver transplant from a deceased donor. They were assessed in four phases: at the time of inclusion on the transplant waiting-list, and 3, 6, and 12 months after receiving the graft. We used a structured interview and SF-36 and Euroqol-5D (EQ-5D) Health Questionnaires. Results: The greater differences were found between pre-transplant and post-transplant stages with less well-being in the stage before the transplant. No significantly differences were observed when comparing the 3, 6 and 12 months from posttransplant stage. Conclusion: The HQRL of liver patients improved after the transplant, being appreciated a tendency to the stabilization from three months onwards. We suggest that the psychological intervention, in liver patients, should be conducted in waiting- list patients and in the first 3 months post-transplant, periods with a poor mental health (anxiety, depression, and stress by fear to the unknown thing) and a low adhesion to the treatment that can generate a smaller graft and/or patient survival.Transplant Research Network RETIC FIS C03/03Junta de Andalucí

¿Es posible la clasificación de individuos perinatales a partir de caracteres objetivos?

X Congreso Nacional de Paleopatología. Univesidad Autónoma de Madrid, septiembre de 200