365 research outputs found
An Analysis of Potential Tax Incentives to Increase Charitable Giving in Puerto Rico
Compares options for improving tax incentives for charitable giving, including lifting the ceiling on deductions as a percentage of adjusted gross income, and estimated effects on nonprofits in Puerto Rico, where average giving is high relative to AGI
Achieving Greater Homeland Security: Who Should Pay, and How?
The terrorist attacks of September 11, 2001 in the United States have broadened the public sector’s role in providing “protective goods and services” to include homeland security in addition to national security and public safety (e.g. police and fire protection). Although it is acknowledged that the federal government has a clear responsibility for taking the lead in shaping homeland security policies, the provision of greater homeland security involves significant participation by state and local governments, and the private sector, in addition to the national government.This paper briefly summarizes why private markets are likely to under-invest in homeland security, leading to a need for public action. It provides an overview of both the range of budgetary and non-budgetary tools used by the United States (U.S.) federal government to “finance” the provision of homeland security, and the budgetary and non-budgetary cost of these federal actions. The paper also identifies and discusses some of the principle challenges faced in ensuring federal homeland security dollars are “well-spent.” While the analysis focuses on the United States, the tools of government employed are applicable to all sovereign nations
Academic Rhetoric in the Policy Arena: The Case of Capital Gains Taxation
We investigate possible explanations for the rhetorical gap that divides producers and influential consumers of economic knowledge, academic economists and policymakers, respectively. We argue that economics lacks a developed theory of how academic research influences political decision making. This theoretical lacuna and the nature of the rhetorical gap have consequences for the effectiveness of academic ideas. We sketch three models, and argue for a process analysis as superior to conventional accounts. The debate on taxation of capital gains is our case study.Economics; Economists; Taxation
The Microarcsecond Sky and Cosmic Turbulence
Radio waves are imprinted with propagation effects from ionized media through
which they pass. Owing to electron density fluctuations, compact sources
(pulsars, masers, and compact extragalactic sources) can display a wide variety
of scattering effects. These scattering effects, particularly interstellar
scintillation, can be exploited to provide *superresolution*, with achievable
angular resolutions (<~ 1 microarcsecond) far in excess of what can be obtained
by very long baseline interferometry on terrestrial baselines. Scattering
effects also provide a powerful sub-AU probe of the microphysics of the
interstellar medium, potentially to spatial scales smaller than 100 km, as well
as a tracer of the Galactic distribution of energy input into the interstellar
medium through a variety of integrated measures. Coupled with future gamma-ray
observations, SKA observations also may provide a means of detecting fainter
compact gamma-ray sources. Though it is not yet clear that propagation effects
due to the intergalactic medium are significant, the SKA will either detect or
place stringent constraints on intergalactic scattering.Comment: 20 pages, 8 figures in 8 PostScript files, to appear in "Science with
the Square Kilometer Array," eds. C. Carilli and S. Rawlings, New Astronomy
Reviews (Elsevier: Amsterdam
The Radial Extent and Warp of the Ionized Galactic Disk. I. A VLBA Survey of Extragalactic Sources Toward the Anticenter
We report multifrequency Very Long Baseline Array observations of twelve
active galactic nuclei seen toward the Galactic anticenter. All of the sources
are at |b| < 10 degrees and seven have |b| < 0.5 degrees. Our VLBA observations
can detect an enhancement in the angular broadening of these sources due to an
extended H II disk, if the orientation of the H II disk in the outer Galaxy is
similar to that of the H I disk. Such an extended H II disk is suggested by the
C IV absorption in a quasar's spectrum, the appearance of H I disks of nearby
spiral galaxies, and models of Ly-alpha cloud absorbers and the Galactic
fountain. We detect eleven of the twelve sources at one or more frequencies;
nine of the sources are compact and suitable for an angular broadening
analysis. A preliminary analysis of the observed angular diameters suggests
that the H II disk does not display considerable warping or flaring and does
not extend to large Galactocentric distances (R >~ 100 kpc). A companion paper
(Lazio & Cordes 1997) combines these observations with those in the literature
and presents a more comprehensive analysis.Comment: 19 pages, LaTeX2e with AASTeX macro aaspp4, accepted for publication
in ApJS, Vol. 115, 1998 April; Figures 1, 3, and 4 included, for figures of
individual sources see
http://astrosun.tn.cornell.edu/students/lazio/Anticenter/anticenterI.htm
Galactic Center Pulsars with the ngVLA
Pulsars in the Galactic Center (GC) are important probes of General
Relativity, star formation, stellar dynamics, stellar evolution, and the
interstellar medium. Despite years of searching, only a handful of pulsars in
the central 0.5 deg are known. The high-frequency sensitivity of ngVLA will
open a new window for discovery and characterization of pulsars in the GC. A
pulsar in orbit around the GC black hole, Sgr A*, will provide an unprecedented
probe of black hole physics and General Relativity.Comment: To be published in the ASP Monograph Series, "Science with a
Next-Generation VLA", ed. E. J. Murphy (ASP, San Francisco, CA
Angular Broadening of Intraday Variable AGN. II. Interstellar and Intergalactic Scattering
We analyze a sample of 58 multi-wavelength, Very Long Baseline Array
observations of active galactic nuclei (AGN) to determine their scattering
properties. Approximately 75% of the sample consists of AGN that exhibit
centimeter-wavelength intraday variability (interstellar scintillation) while
the other 25% do not show intraday variability. We find that interstellar
scattering is measurable for most of these AGN, and the typical broadening
diameter is 2 mas at 1 GHz. We find that the scintillating AGN are typically at
lower Galactic latitudes than the non-scintillating AGN, consistent with the
scenario that intraday variability is a propagation effect from the Galactic
interstellar medium. The magnitude of the inferred interstellar broadening
measured toward the scintillating AGN, when scaled to higher frequencies, is
comparable to the diameters inferred from analyses of the light curves for the
more well-known intraday variable sources. However, we find no difference in
the amount of scattering measured toward the scintillating versus
non-scintillating AGN. A consistent picture is one in which the scintillation
results from localized regions ("clumps") distributed throughout the Galactic
disk, but which individually make little contribution to the angular
broadening. Of the 58 AGN observed, 37 (64%) have measured redshifts. At best,
a marginal trend is found for scintillating (non-scintillating) AGN to have
smaller (larger) angular diameters at higher redshifts. We also use our
observations to try to constrain the possibility of intergalactic scattering.
While broadly consistent with the scenario of a highly turbulent intergalactic
medium, our observations do not place significant constraints on its
properties.Comment: 13 pages, 4 figures; AASTeX format; ApJ in pres
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