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Technology, Wages and Skill Shortages: Evidence from UK Micro Data
Why have skill shortages continue to persist despite increases in training and the skill levels of the
workforce? We argue that technical progress has raised the demand for skilled labour to mach the observed
increase in supply. We provide econometric evidence in support of this hypothesis, showing that skill shortages
are higher for establishments that use advanced technology in the production process. We also provide
econometric evidence that hiring difficulties are inversely related to the relative wage, as theory would suggest.
Our results have clear implications for policy. If technological progress continues to be skill biased, policies that
address skills deficiencies will only be successful if they produce a continual, rather than a temporary, increase in
levels of skills among the workforc
Minimum variance estimates of signal derivatives - A problem in instrument landing systems
Minimum variance estimates of signal derivatives with application to case of aircraft descent rate in instrument landing system
A geometrical picture for finite dimensional spin glasses
A controversial issue in spin glass theory is whether mean field correctly
describes 3-dimensional spin glasses. If it does, how can replica symmetry
breaking arise in terms of spin clusters in Euclidean space? Here we argue that
there exist system-size low energy excitations that are sponge-like, generating
multiple valleys separated by diverging energy barriers. The droplet model
should be valid for length scales smaller than the size of the system (theta >
0), but nevertheless there can be system-size excitations of constant energy
without destroying the spin glass phase. The picture we propose then combines
droplet-like behavior at finite length scales with a potentially mean field
behavior at the system-size scale.Comment: 7 pages; modified references, clarifications; to appear in EP
Reimagining the General Health Questionnaire as a measure of emotional wellbeing: A study of postpartum women in Malta
Background: Postpartum health has been subject to a focus on psychological morbidity, despite positive associations between postpartum recovery and maternal emotional wellbeing. There are currently many validated tools to measure wellbeing and related concepts, including non-psychiatric morbidity. The General Health Questionnaire, 12 items (GHQ-12) is one such instrument, widely used and validated in several languages. Its use in postpartum settings has been documented with disagreement about the instrument's utility in this population, particularly in relation to scoring method and threshold. The GHQ-12 has never been translated into Maltese. This study explored the psychometric properties of the GHQ-12 in a Maltese postpartum population to consider if the use of a different scoring method (visual analogue scale) in the GHQ-12 can determine postpartum wellbeing. Methods: One hundred and twenty-four postpartum women recruited from one hospital in Malta completed the translated and adapted GHQ-12 as a wellbeing measure (GHQ-12(WB)) at four postpartum time points. The psychometric properties of the GHQ-12(WB) were explored using confirmatory factor analysis, discriminant and divergent validity and reliability analysis. Results: The GHQ-12(WB) demonstrated good divergent and known-groups validity and internal consistency. No models offered a good fit to the data. The overall consistent best-fit to the data was an eight item, two factor model (GHQ-8). Model fit improved across all models in terms of CFI at 13 weeks. Conclusion: Findings generally support the reliability and validity of the Maltese version of the GHQ-12(WB). Model fit changes over time reflect the dynamic nature of postpartum recovery. Further evaluation of the GHQ-8(WB) is recommended. © 2013 Australian College of Midwives
Measuring the Higgs to Photon-Photon Branching Ratio at the Next Linear Collider
We examine the prospects for measuring the photon-photon branching ratio of a
Standard-Model-like Higgs boson () at the Next Linear Collider when
the Higgs boson is produced via --fusion: .
In particular, we study the accuracy of such a measurement and the statistical
significance of the associated signal as a function of the electromagnetic
calorimeter resolution and the Higgs boson mass. We compare results for the
--fusion production/measurement mode with the results obtained for the
production/measurement mode in a
parallel earlier study.Comment: 5 pages, full postscript file also available via anonymous ftp at
ftp://ucdhep.ucdavis.edu/gunion/htogamgam_sm96.ps To appear in ``Proceedings
of the 1996 DPF/DPB Summer Study on New Directions for High Energy Physics'
The Lives of Stars: Insights From the TGAS-RAVE-LAMOST Dataset
In this paper we investigate how the chemical and kinematic properties of
stars vary as a function of age. Using data from a variety of photometric,
astrometric and spectroscopic surveys, we calculate the ages, phase space
information and orbits for 125,000 stars covering a wide range of stellar
parameters.
We find indications that the inner regions of the disk reached high levels of
enrichment early, while the outer regions were more substantially enriched in
intermediate and recent epochs. We consider these enrichment histories through
comparison of the ages of stars, their metallicities, and kinematic properties,
such as their angular momentum in the solar neighborhood (which is a proxy for
orbital radius). We calculate rates at which the velocity dispersions evolve,
investigate the Oort constants for different aged populations (finding a
slightly negative and for all ages, being most negative for the oldest stars), as well as examine
the behavior of the velocity vertex deviation angle as a function of age (which
we find to fall from 15 degrees for the 2 Gyr aged population to 6
degrees at around 6.5 Gyr of age, after which it remains unchanged). We find
evidence for stellar churning, and find that the churned stars have a slightly
younger age distribution than the rest of the data.Comment: 18 Pages, 14 Figures, Accepted Ap
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