12,546 research outputs found
Foreign aid and business bottlenecks : a study of aid effectiveness
This paper proposes a new framework to analyze aid effectiveness. Using World Bank firm survey data and OECD aid flow data, the authors analyze whether aid targets areas that firms in developing countries have identified as obstacles for their growth and whether aid actually improves firms'perceptions of those areas. The analysis finds that aid does target the areas that firms have identified as obstacles; aid funding trade related projects is particularly effective in targeting the correct countries. For the most part, aid has a positive impact on improving firms'perceptions, particularly in the business environment. And for each target area, smaller aid disbursements tend to be more effective at improving firm perceptions than larger disbursements.Environmental Economics&Policies,Development Economics&Aid Effectiveness,Disability,Gender and Health,School Health
Regional index of sustainable economic well-being development project: final report
This report presents results from a development project carried out by nef (the new economics foundation) on behalf of emda (the East Midlands Development Agency) and Natural England, to improve the methodologies used in the calculation of the R-ISEW (Regional Index of Sustainable Economic Well-Being)
Mu-tau neutrino refraction and collective three-flavor transformations in supernovae
We study three-flavor collective neutrino transformations in the
dense-neutrino region above the neutrino sphere of a supernova core. We find
that two-flavor conversions driven by the atmospheric mass difference and the
13-mixing angle capture the full effect if one neglects the second-order
difference between the muon and tau neutrino refractive index. Including this
"mu-tau matter term" provides a resonance at a density of approximately 3 x
10^7 g cm^-3 that typically causes significant modifications of the overall
electron neutrino and antineutrino survival probabilities. This effect is
surprisingly sensitive to deviations from maximal 23-mixing, being different
for each octant.Comment: 9 pages, 7 figures. New presentation of results, version to be
published in PR
Lateral downflows in sunspot penumbral filaments and their temporal evolution
We study the temporal evolution of downflows observed at the lateral edges of
penumbral filaments in a sunspot located very close to the disk center. Our
analysis is based on a sequence of nearly diffraction-limited scans of the Fe I
617.3 nm line taken with the CRisp Imaging Spectro-Polarimeter at the Swedish 1
m Solar Telescope. We compute Dopplergrams from the observed intensity profiles
using line bisectors and filter the resulting velocity maps for subsonic
oscillations. Lateral downflows appear everywhere in the center-side penumbra
as small, weak patches of redshifts next to or along the edges of blueshifted
flow channels. These patches have an intermittent life and undergo mergings and
fragmentations quite frequently. The lateral downflows move together with the
hosting filaments and react to their shape variations, very much resembling the
evolution of granular convection in the quiet Sun. There is a good relation
between brightness and velocity of the flow structures in the center-side
penumbra, with downflows being darker than upflows on average, which is again
reminiscent of quiet Sun convection. These results point to the existence of
overturning convection in sunspot penumbrae, with elongated cells forming
filaments where the flow is upward but very inclined, and weak lateral downward
flows. In general, the circular polarization profiles emerging from the lateral
downflows do not show sign reversals, although sometimes we detect three-lobed
profiles which are suggestive of opposite magnetic polarities in the pixel.Comment: 16 pages, 15 figures. Accepted for publication in ApJ. Movies are
available at http://spg.iaa.es/download
Nuevos datos sobre las helmintofaunas parasíticas de micromamíferos en las islas Pitiusas. I.
Abstract not availabl
Pricing policies for a two-part exhaustible resource cartel: The case of OPEC
Prepared in association with the Sloan School of Management and the Dept. of EconomicsThis paper examines pricing policies for OPEC under the assumption that
the cartel is composed of a block of spender countries with large cash
needs and a block of saver countries with little immediate need for cash
and a lower rate of discount. The decision problem for the two-part cartel
is embodied in a game-theoretic framework and the optimal bargaining solution
is computed using results from the theory of cooperative games developed by
Nash. The set of feasible bargaining points -- and the corresponding Nash
solution -- is computed under two assumptions on the behavior of output shares:
that they are subject to choice and that they are fixed at historical values.
Our results suggest that for fixed output shares, there is little room for
bargaining and the price path approximates the optimal monopoly price path.
If the shares are subject to control, optimal paths depend significantly on
the relative bargaining power of each block.National Science Foundation NSF Grant # GS 41519 and NSF Grant # SIA 75-0073
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Enhancement of Visual Field Predictions with Pointwise Exponential Regression (PER) and Pointwise Linear Regression (PLR).
PurposeThe study was conducted to evaluate threshold smoothing algorithms to enhance prediction of the rates of visual field (VF) worsening in glaucoma.MethodsWe studied 798 patients with primary open-angle glaucoma and 6 or more years of follow-up who underwent 8 or more VF examinations. Thresholds at each VF location for the first 4 years or first half of the follow-up time (whichever was greater) were smoothed with clusters defined by the nearest neighbor (NN), Garway-Heath, Glaucoma Hemifield Test (GHT), and weighting by the correlation of rates at all other VF locations. Thresholds were regressed with a pointwise exponential regression (PER) model and a pointwise linear regression (PLR) model. Smaller root mean square error (RMSE) values of the differences between the observed and the predicted thresholds at last two follow-ups indicated better model predictions.ResultsThe mean (SD) follow-up times for the smoothing and prediction phase were 5.3 (1.5) and 10.5 (3.9) years. The mean RMSE values for the PER and PLR models were unsmoothed data, 6.09 and 6.55; NN, 3.40 and 3.42; Garway-Heath, 3.47 and 3.48; GHT, 3.57 and 3.74; and correlation of rates, 3.59 and 3.64.ConclusionsSmoothed VF data predicted better than unsmoothed data. Nearest neighbor provided the best predictions; PER also predicted consistently more accurately than PLR. Smoothing algorithms should be used when forecasting VF results with PER or PLR.Translational relevanceThe application of smoothing algorithms on VF data can improve forecasting in VF points to assist in treatment decisions
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