3,101 research outputs found

    Using Linked Survey and Administrative Data to Better Measure Income: Implications for Poverty, Program Effectiveness and Holes in the Safety Net

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    We examine the consequences of underreporting of transfer programs in household survey data for several prototypical analyses of low-income populations. We focus on the Current Population Survey (CPS), the source of official poverty and inequality statistics, but provide evidence that our qualitative conclusions are likely to apply to other surveys. We link administrative data for food stamps, TANF, General Assistance, and subsidized housing from New York State to the CPS at the individual level. Program receipt in the CPS is missed for over one-third of housing assistance recipients, 40 percent of food stamp recipients, and 60 percent of TANF and General Assistance recipients. Dollars of benefits are also undercounted for reporting recipients, particularly for TANF, General Assistance and housing assistance. We find that the survey data sharply understate the income of poor households, as conjectured in past work by one of the authors. Underreporting in the survey data also greatly understates the effects of anti-poverty programs and changes our understanding of program targeting, often making it seem that welfare programs are less targeted to both the very poorest and middle income households than they are. Using the combined data rather than survey data alone, the poverty reducing effect of all programs together is nearly doubled while the effect of housing assistance is tripled. We also re-examine the coverage of the safety net, specifically the share of people without work or program receipt. Using the administrative measures of program receipt rather than the survey ones often reduces the share of single mothers falling through the safety net by one-half or more

    Quality assurance in higher education - meta-evaluationof multi-stage evaluation procedures in Germany

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    Systematic procedures for quality assurance and improvement through evaluation have been in place in Western Europe since the mid 1980s and in Germany since the mid 1990s. As studies in Europe and beyond show that multi-stage evaluation procedures as the main quality assurance instrument for evaluation of teaching and learning in higher education institutions have proved reliable and have gained acceptance, in Germany (as well as in other countries) the evaluation of teaching and learning through internal and external evaluations has long come under the fire of criticism. Our results of the first comprehensive and representative investigation of procedures for the evaluation of teaching and learning in Germany show that former participants in the evaluations (reviewers and those reviewed) are satisfied all in all with the multi-stage procedure. They are convinced that the goals of quality assurance and improvement were achieved. Suggestions for improving the procedures target individual aspects, such as, for example, the composition of the review panel. Against this background, it makes sense to perform regular quality assessments of the procedures for quality assurance and improvemen

    Fluctuation Theorem in Rachet System

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    Fluctuation Theorem(FT) has been studied as far from equilibrium theorem, which relates the symmetry of entropy production. To investigate the application of this theorem, especially to biological physics, we consider the FT for tilted rachet system. Under, natural assumption, FT for steady state is derived.Comment: 6 pages, 2 figure

    The grand canonical ABC model: a reflection asymmetric mean field Potts model

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    We investigate the phase diagram of a three-component system of particles on a one-dimensional filled lattice, or equivalently of a one-dimensional three-state Potts model, with reflection asymmetric mean field interactions. The three types of particles are designated as AA, BB, and CC. The system is described by a grand canonical ensemble with temperature TT and chemical potentials TλAT\lambda_A, TλBT\lambda_B, and TλCT\lambda_C. We find that for λA=λB=λC\lambda_A=\lambda_B=\lambda_C the system undergoes a phase transition from a uniform density to a continuum of phases at a critical temperature T^c=(2π/3)1\hat T_c=(2\pi/\sqrt3)^{-1}. For other values of the chemical potentials the system has a unique equilibrium state. As is the case for the canonical ensemble for this ABCABC model, the grand canonical ensemble is the stationary measure satisfying detailed balance for a natural dynamics. We note that T^c=3Tc\hat T_c=3T_c, where TcT_c is the critical temperature for a similar transition in the canonical ensemble at fixed equal densities rA=rB=rC=1/3r_A=r_B=r_C=1/3.Comment: 24 pages, 3 figure

    Perfect magnetohydrodynamics as a field theory

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    We propose the generally covariant action for the theory of a self-coupled complex scalar field and electromagnetism which by virtue of constraints is equivalent, in the regime of long wavelengths, to perfect magnetohydrodynamics (MHD). We recover from it the Euler equation with Lorentz force, and the thermodynamic relations for a prefect fluid. The equation of state of the latter is related to the scalar field's self potential. We introduce 1+3 notation to elucidate the relation between MHD and field variables. In our approach the requirement that the scalar field be single valued leads to the quantization of a certain circulation in steps of \hbar; this feature leads, in the classical limit, to the conservation of that circulation. The circulation is identical to that in Oron's generalization of Kelvin's circulation theorem to perfect MHD; we here characterize the new conserved helicity associated with it. We also demonstrate the existence for MHD of two Bernoulli-like theorems for each spacetime symmetry of the flow and geometry; one of these is pertinent to suitably defined potential flow. We exhibit the conserved quantities explicitly in the case that two symmetries are simultaneously present, and give examples. Also in this case we exhibit a new conserved MHD circulation distinct from Oron's, and provide an example.Comment: RevTeX, 16 pages, no figures; clarifications added and typos corrected; version to be published in Phys. Rev.

    Experimental demonstration of violations of the second law of thermodynamics for small systems and short time scales

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    We experimentally demonstrate the fluctuation theorem, which predicts appreciable and measurable violations of the second law of thermodynamics for small systems over short time scales, by following the trajectory of a colloidal particle captured in an optical trap that is translated relative to surrounding water molecules. From each particle trajectory, we calculate the entropy production/consumption over the duration of the trajectory and determine the fraction of second law–defying trajectories. Our results show entropy consumption can occur over colloidal length and time scales

    Time series of high resolution spectra of SN 2014J observed with the TIGRE telescope

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    We present a time series of high resolution spectra of the Type Ia supernova 2014J, which exploded in the nearby galaxy M82. The spectra were obtained with the HEROS echelle spectrograph installed at the 1.2 m TIGRE telescope. We present a series of 33 spectra with a resolution of R = 20, 000, which covers the important bright phases in the evolution of SN 2014J during the period from January 24 to April 1 of 2014. The spectral evolution of SN 2014J is derived empirically. The expansion velocities of the Si II P-Cygni features were measured and show the expected decreasing behaviour, beginning with a high velocity of 14,000 km/s on January 24. The Ca II infrared triplet feature shows a high velocity component with expansion velocities of > 20, 000 km/s during the early evolution apart from the normal component showing similar velocities as Si II. Further broad P-Cygni profiles are exhibited by the principal lines of Ca II, Mg II and Fe II. The TIGRE SN 2014J spectra also resolve several very sharp Na I D doublet absorption components. Our analysis suggests interesting substructures in the interstellar medium of the host galaxy M82, as well as in our Milky Way, confirming other work on this SN. We were able to identify the interstellar absorption of M82 in the lines of Ca II H & K at 3933 and 3968 A as well as K I at 7664 and 7698 A. Furthermore, we confirm several Diffuse Interstellar Bands, at wavelengths of 6196, 6283, 6376, 6379 and 6613 A and give their measured equivalent widths.Comment: 11 pages, 10 figures, accepted for publication in MNRA
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