EFECTOS ASIMÉTRICOS DE LA POLÍTICA MONETARIA

El objetivo de este documento es obtener evidencia empírica acerca de la existencia de efectos asimétricos de la política monetaria sobre el nivel de actividad económica, con base en el comportamiento de la tasa de interés. Se observa un efecto asimétrico de la política monetaria cuando tasas de interés por encima de su nivel fundamental tienen un efecto sobre la actividad económica significativamente distinto del que tendría una tasa de interés por debajo de su nivel fundamental.La identificación de cambios en la tasa de interés que reflejan cambios de política se realiza por mínimos cuadrados en dos etapas. En la primera etapa, el nivel fundamental de la tasa de interés se estima con una regla de Taylor modificada y sus residuos son utilizados para identificar el estado de la política. La segunda etapa consiste en una regresión del producto real sobre una constante y los valores rezagados de los residuos positivos y negativos obtenidos en la primera etapa. La asimetría vendría determinada por la significancia estadística de los coeficientes individuales de los residuos positivos y negativos y de la diferencia entre estos.La evidencia empírica, para el periodo 1994:01-2002:11, sugiere la existencia de una asimetría débil de la política monetaria. Lo anterior debido a que aunque los incrementos y disminuciones en la tasa de interés afectan el nivel de producción significativamente, la diferencia del impacto no resulta significativa.AbstractThe objective of this paper is to obtain empirical evidence about the existence of asymmetric effects of monetary policy over economic activity, based on interest rate behavior. Monetary policy shows an asymmetric effect when an interest rate over their fundamental level have an impact on economic activity that is significantly different from that when interest rate are below its fundamental level.Changes in interest rate that reflect changes of policy are identified using two stage least squares. In the first stage, the fundamental level of the interest rate is estimated with a modified Taylor rule and residuals are used to identify the state of the policy. The second stage consists of a regression of the real output on a constant and lagged values of the positive and negative residuals obtained in the first stage. The asymmetry would come determined by the statistical significance of individual coefficients of positive and negative residuals and the difference between them.The empirical evidence, over the 1994:01-2002:11 period, suggests the existence of weak asymmetry of monetary policy. Although increases and reductions in interest rate affect the production level significantly, the difference of the impact is not significant.

Three essays on liquidity

Doutoramento em Gestão.

Large unburnt areas, not small unburnt patches, are needed to conserve avian diversity in fire-prone landscapes

Mitigating the impacts of large-scale fires on biodiversity is becoming increasingly important as their frequency increases. In response, fire managers have engaged with the concept that retaining small unburnt residual areas of vegetation within extensively burnt landscapes may facilitate biodiversity conservation. However, it remains uncertain how the size and isolation of these unburnt residuals influence faunal distributions, persistence and recovery following fire. We used a replicated observation study to test bird responses to the size and isolation of unburnt residuals in a mallee woodland area recently burnt by a 28 000 ha wildfire in southern Australia. The scale of our study provided a rare opportunity to consider the responses of large mobile organisms to fire-induced habitat fragmentation. Within five replicated spatial blocks, we crossed two levels of isolation with large (5-7 ha) and small (1-3 ha) unburnt patches and matrix sites burnt 5 years previously. We compared these site types to six continuous (non-fragmented) unburnt sites. We surveyed each site on eight occasions. Most birds occurred more frequently in unburnt habitat beyond the extent of the fire. Bird responses to the availability and spatial distribution of unburnt remnants within the fire were largely influenced by their ability to use the recently burnt matrix. Occurrence of five species was higher in unburnt residuals when more of the landscape within 500 m was burnt. A fire refuge effect may be likely for two competitive species that occurred more frequently in unburnt residuals than in the burnt matrix or continuous unburnt habitat. For the weebill, recolonization following fire was likely to occur gradually over time from ex situ sources. Synthesis and applications. To maintain avian diversity in fire-prone landscapes, our results suggest a need to shift management focus from creating networks of small unburnt patches towards preserving large, intact areas of habitat. However, five species common to the burnt matrix preferentially selected residual patches when unburnt resources were locally scarce. Therefore, to benefit birds, land managers should limit the extent of applied burns and use narrow burns. When planning large burns, practitioners should consider that a number of species will remain absent from the landscape for several decades.

Cultural adaptation and validation of the Health Literacy Questionnaire (HLQ): robust nine-dimension Danish language confirmatory factor model

Health literacy is an important construct in population health and healthcare requiring rigorous measurement. The Health Literacy Questionnaire (HLQ), with nine scales, measures a broad perception of health literacy. This study aimed to adapt the HLQ to the Danish setting, and to examine the factor structure, homogeneity, reliability and discriminant validity. The HLQ was adapted using forward-backward translation, consensus conference and cognitive interviews (n = 15). Psychometric properties were examined based on data collected by face-to-face interview (n = 481). Tests included difficulty level, composite scale reliability and confirmatory factor analysis (CFA). Cognitive testing revealed that only minor re-wording was required. The easiest scale to respond to positively was 'Social support for health', and the hardest were 'Navigating the healthcare system' and 'Appraisal of health information'. CFA of the individual scales showed acceptably high loadings (range 0.49-0.93). CFA fit statistics after including correlated residuals were good for seven scales, acceptable for one. Composite reliability and Cronbach's α were >0.8 for all but one scale. A nine-factor CFA model was fitted to items with no cross-loadings or correlated residuals allowed. Given this restricted model, the fit was satisfactory. The HLQ appears robust for its intended application of assessing health literacy in a range of settings. Further work is required to demonstrate sensitivity to measure changes.