2,160 research outputs found

    Real Exchange Rates and Time-Varying Trade Costs

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    Previous empirical work on the Purchasing Power Parity does not explicitly account for time-varying trade costs. Motivated by the recent gravity literature we incorporate a microfounded measure of trade costs into two nonlinear regression models for the real exchange rate. Using data for the dollar-sterling real exchange rate from 1830 to 2005, we provide significant evidence in favor of a positive relation between the level of trade costs and the degree of persistence of the real exchange rate.

    Economic Impacts of Restricted Animal Movements in Mexico Due to Increased Mexican Regional Bovine Health Criteria

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    Tuberculosis restrictions on animal movement have important implications for Mexican producers and consumers as well as the U.S. beef cattle industry. The restrictions cause decreased Mexican cattle exports, increased domestic fed beef production, and decreased fed beef imports. The Mexican beef industry incurs greater costs due to increased interregional cattle and meat shipments and changes in regional beef cattle production in Mexico.Livestock Production/Industries,

    Specifying Smooth Transition Regression Models in the Presence of Conditional Heteroskedasticity of Unknown Form

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    The specification of Smooth Transition Regression models consists of a sequence of tests, which are typically based on the assumption of i.i.d. errors. In this paper we examine the impact of conditional heteroskedasticity and investigate the performance of several heteroskedasticity robust versions. Simulation evidence indicates that conventional tests can frequently result in finding spurious nonlinearity. Conversely, when the true process is nonlinear in mean the tests appear to have low size adjusted power and can lead to the selection of misspecified models. The above deficiencies also hold for tests based on Heteroskedasticity Consistent Covariance Matrix Estimators but not for the Fixed Design Wild Bootstrap. We highlight the importance of robust inference through empirical applications.

    A fast full-search adaptive vector quantizer for video coding

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    This paper presents a novel VQ structure which provides very good quality encoding for video sequences and exploits the computational savings gained from a fast-search algorithm. It uses an adaptive-search, variable-length encoding method which allows for very fast matching of a wide range of transmission rates. Both the encoding quality and the computational benefits from the fast-search algorithm are presented. Simulations show that full-search tree residual VQ (FTRVQ) can provide up to 3 dB improvement over a similar RVQ encoder on video sequences

    Family Friendly? The Impact on Children of the Family Migration Rules: A Review of the Financial Requirements

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    This is the final version of the article. Available from the office of the Children's Commissioner via the link in this record.This report was commissioned by the Children’s Commissioner for England from Middlesex University and the Joint Council for the Welfare of Immigrants (JCWI).Children's Commissioner of Englan

    Risk and resilience: exploring the potential of LGBTQ third sector and academic partnership

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    The Risk and Resilience Explored [RaRE] Project (2010–2016) was a collaborative process involving a third sector agency, university partners and volunteers to better understand the risk and resilience factors associated with specific mental health issues among lesbian, gay, bisexual, trans, and queer (LGBTQ) people. In this article, we discuss the project’s collaborative ethos, based on a Community-Based Participatory Research (CBPR) approach. We explain how the CBPR approach benefitted from including academic partners from the onset of the project, as well as from the direct and indirect engagement of community volunteers. We then explore some of our experience of third sector and academic partner collaboration in more depth, highlighting topic summaries salient to this partnership: support and continuity, upskilling of staff and volunteers for mutual benefit, accessible communication across sectors, and aligning priorities. We conclude by setting out recommendations based on our experience for those interested in developing similarly collaborative projects

    An examination of the precipitation delivery mechanisms for Dolleman Island, eastern Antarctic Peninsula

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    Copyright @ 2004 Wiley-BlackwellThe variability of size and source of significant precipitation events were studied at an Antarctic ice core drilling site: Dolleman Island (DI), located on the eastern coast of the Antarctic Peninsula. Significant precipitation events that occur at DI were temporally located in the European Centre for Medium-Range Weather Forecasting (ECMWF) reanalysis data set, ERA-40. The annual and summer precipitation totals from ERA-40 at DI both show significant increases over the reanalysis period. Three-dimensional backwards air parcel trajectories were then run for 5 d using the ECMWF ERA-15 wind fields. Cluster analyses were performed on two sets of these backwards trajectories: all days in the range 1979–1992 (the climatological time-scale) and a subset of days when a significant precipitation event occurred. The principal air mass sources and delivery mechanisms were found to be the Weddell Sea via lee cyclogenesis, the South Atlantic when there was a weak circumpolar trough (CPT) and the South Pacific when the CPT was deep. The occurrence of precipitation bearing air masses arriving via a strong CPT was found to have a significant correlation with the southern annular mode (SAM); however, the arrival of air masses from the same region over the climatological time-scale showed no such correlation. Despite the dominance in both groups of back trajectories of the westerly circulation around Antarctica, some other key patterns were identified. Most notably there was a higher frequency of lee cyclogenesis events in the significant precipitation trajectories compared to the climatological time-scale. There was also a tendency for precipitation trajectories to come from more northerly latitudes, mostly from 50–70°S. The El Niño Southern Oscillation (ENSO) was found to have a strong influence on the mechanism by which the precipitation was delivered; the frequency of occurrence of precipitation from the east (west) of DI increased during El Niño (La Niña) events

    Adaptive-rate tree-structured residual vector quantization

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    Full-search vector quantization (VQ) provides optimal results only with high memory and computational cost. We describe the computational and memory requirements of tree-structured VQ, residual VQ (RVQ), and tree-structured RVQ. We present multiple-rate, adaptive-search implementations of these VQ structures, and simulation results with video sequences. Tree-structured RVQ provides up to 1.5 db PSNR quality improvements over RVQ, as well as significant perceptual improvement. These algorithms maintain many of the benefits of full-search VQ, while providing trade-offs between computational, storage, and performance requirements
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