3,406 research outputs found

    Analysing The Effects Of Tax Benefit Reforms On Income Distribution: A Decomposition Approach

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    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.

    Family labour supply and taxes in Ireland

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    Taxation;Labour Supply

    CT-duality as a local property of the world-sheet

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    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

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    Static solutions of large-NN quantum dilaton gravity in 1+11+1 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

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    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

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    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

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    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

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    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

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    We argue that, classically, ss-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 SS-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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