3,413 research outputs found
Analysing The Effects Of Tax Benefit Reforms On Income Distribution: A Decomposition Approach
To assess the impact of tax-benefit policy changes on income distribution over time, we suggest a methodology based on counterfactual simulations. We start by decomposing changes in inequality/poverty indices into three contributions: reforms of the tax-benefit structure (eligibility rules, tax rate structure, etc.); changes in nominal levels of both market incomes and tax-benefit parameters (e.g. benefit amounts, tax bands); and all other changes in the underlying population (including market income inequality and demographic composition). Then, the decomposition helps to extract an absolute measure of the impact of tax-benefit changes on inequality when evaluated against a distributionally-neutral benchmark, i.e. a situation where tax-benefit parameters are adjusted in line with income growth. We apply this measure to assess recent policy changes in twelve European countries. Finally, the full decomposition allows quantifying the relative role of policy changes compared to all other factors. We provide an illustration on France and Ireland and check the sensitivity of the results to the decomposition order.inequality, poverty, Tax-benefit policy, decomposition, microsimulation.
Female labour supply in farm households: Farm and off-farm participation
Female Workers;Farms;Labour Supply
CT-duality as a local property of the world-sheet
In the present article, we study the local features of the world-sheet in the
case when probe bosonic string moves in antisymmetric background field. We
generalize the geometry of surfaces embedded in space-time to the case when the
torsion is present. We define the mean extrinsic curvature for spaces with
Minkowski signature and introduce the concept of mean torsion. Its orthogonal
projection defines the dual mean extrinsic curvature. In this language, the
field equation is just the equality of mean extrinsic curvature and extrinsic
mean torsion, which we call CT-duality. To the world-sheet described by this
relation we will refer as CT-dual surface.Comment: Latex, 15 pages, 2 Figure
Quantum Black Holes
Static solutions of large- quantum dilaton gravity in dimensions are
analyzed and found to exhibit some unusual behavior. As expected from previous
work, infinite-mass solutions are found describing a black hole in equilibrium
with a bath of Hawking radiation. Surprisingly, the finite mass solutions are
found to approach zero coupling both at the horizon and spatial infinity, with
a ``bounce'' off of strong coupling in between. Several new zero mass solutions
-- candidate quantum vacua -- are also described.Comment: 14 pages + 6 figure
Measuring Up 2006: The National Report Card on Higher Education
Measures the performance of the U.S. and of each state in providing education and training beyond high school. Compares national and state higher education performance with other nations
Low-Lying Dirac Eigenmodes, Topological Charge Fluctuations and the Instanton Liquid Model
The local structure of low-lying eigenmodes of the overlap Dirac operator is
studied. It is found that these modes cannot be described as linear
combinations of 't Hooft "would-be" zeromodes associated with instanton
excitations that underly the Instanton Liquid Model. This implies that the
instanton liquid scenario for spontaneous chiral symmetry breaking in QCD is
not accurate. More generally, our data suggests that the vacuum fluctuations of
topological charge are not effectively dominated by localized lumps of unit
charge with which the topological "would-be" zeromodes could be associated.Comment: Presented by I. Horvath at the NATO Advanced Research Workshop
"Confinement, Topology, and other Non-Perturbative Aspects of QCD", January
21-27, 2002, Stara Lesna, Slovakia. 12 pages, 6 figures, uses crckapb.st
Scale Anomaly Induced Instanton Interaction
The binary interaction of large size instantons in a SU(2) Yang-Mills theory
is obtained from the one-loop effective action for the field strength. The
instanton interaction is calculated as a function of the instanton separation
and in dependence on radius and relative orientation of the instantons. Two
equally oriented instantons with radii large compared with the scale defined by
the gluon condensate have purely attractive interaction, whereas the
interaction of maximal disoriented instantons is repulsive. We argue that the
medium range attractive interaction of the instantons generally holds and is
solely due to the instability of the perturbative vacuum.Comment: 11 LaTex pages (3 figures available on request), in press by Physics
Letters B, UNITUE-THEP-4-199
Torons and black hole entropy
We consider a supersymmetric system of D-5-branes compactified on a 5-torus
with a self-dual background field strength on a 4-torus and carrying
left-moving momentum along a circle. The corresponding supergravity solution
describes a 5-dimensional black hole with a regular horizon. The entropy of
this black hole may be explained in terms of the Landau degeneracy for open
strings stretching between different branes. In the gauge theory approximation
this D-5-brane system is described by a super Yang-Mills theory with a t'Hooft
twist. By choosing a supersymmetric branch of the theory we obtain perfect
agreement with the entropy formula. The result relies on the number of massless
torons associated with the gauge field components that obey twisted boundary
conditions.Comment: 31 pages, latex. Some equations corrected. Final version to be
published in Nuclear Physics
S-Wave Scattering of Charged Fermions by a Magnetic Black Hole
We argue that, classically, -wave electrons incident on a magnetically
charged black hole are swallowed with probability one: the reflection
coefficient vanishes. However, quantum effects can lead to both electromagnetic
and gravitational backscattering. We show that, for the case of extremal,
magnetically charged, dilatonic black holes and a single flavor of low-energy
charged particles, this backscattering is described by a perturbatively
computable and unitary -matrix, and that the Hawking radiation in these
modes is suppressed near extremality. The interesting and much more difficult
case of several flavors is also discussed.Comment: 9p
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