64,767 research outputs found
Race and Home Ownership from the End of the Civil War to the Present
We present new estimates of home ownership for black and white households from 1870 to 2007. Black ownership increased by 46 percentage points, whereas white ownership increased by 20 points. Remarkably, 25 of the 26 point narrowing occurred between 1870 and 1910. Part of this early convergence is accounted for by falling white ownership due to movement out of agriculture, but most is accounted for by post-emancipation gains among blacks. After 1910, white and black households increased ownership, but the racial gap barely changed. We discuss the influence of residential segregation, public policy, and permanent income on the ownership gap.
QCD Factorization for Semi-Inclusive Deep-Inelastic Scattering at Low Transverse Momentum
We demonstrate a factorization formula for semi-inclusive deep-inelastic
scattering with hadrons in the current fragmentation region detected at low
transverse momentum. To facilitate the factorization, we introduce the
transverse-momentum dependent parton distributions and fragmentation functions
with gauge links slightly off the light-cone, and with soft-gluon radiations
subtracted. We verify the factorization to one-loop order in perturbative
quantum chromodynamics and argue that it is valid to all orders in perturbation
theory.Comment: 28 pages, figures include
Derivation of the Gauge Link in Light Cone Gauge
In light cone gauge, a gauge link at light cone infinity is necessary for
transverse momentum-dependent parton distribution to restore the gauge
invariance in some specific boundary conditions. We derive such transverse
gauge link in a more regular and general method. We find the gauge link at
light cone infinity naturally arises from the contribution of the pinched
poles: one is from the quark propagator and the other is hidden in the gauge
vector field in light cone gauge. Actually, in the amplitude level, we have
obtained a more general gauge link over the hypersurface at light cone infinity
which is beyond the transverse direction. The difference of such gauge link
between semi-inclusive deep inelastic scattering and Drell-Yan processes can
also be obtained directly and clearly in our derivation.Comment: 18 pages, 5 figures, published versio
Renormalization-group anatomy of transverse-momentum dependent parton distribution functions in QCD
The ultraviolet and rapidity divergences of transverse-momentum dependent
parton distribution functions with lightlike and transverse gauge links is
studied, also incorporating a soft eikonal factor. We find that in the
light-cone gauge with -independent pole prescriptions extra divergences
appear which amount, at one-loop, to a cusp-like anomalous dimension. We show
that such contributions are absent when the Mandelstam-Leibbrandt prescription
is used. In the first case, the soft factor cancels the anomalous-dimension
defect, while in the second case its ultraviolet-divergent part reduces to
unity.Comment: 10 pages, 3 figures; needs ws-mpla-hep.cls (supplied). Talk presented
by the first author at Workshop on "Recent Advances in Perturbative QCD and
Hadronic Physics", 20--25 July 2009, ECT*, Trento, Italy, in Honor of Prof.
Anatoly Efremov's 75th birthda
The Labor Market Effects of the 1960s Riots
Between 1964 and 1971, hundreds of riots erupted in American cities, resulting in large numbers of injuries, deaths, and arrests, as well as in considerable property damage that was concentrated in predominantly black neighborhoods. There have been few studies of a systematic, econometric nature that examine the impact of the riots on the relative economic status of African Americans, or on the cities and neighborhoods in which the riots took. We present two complementary empirical analyses. The first uses aggregate, city-level data on income, employment, unemployment, and the area’s racial composition from the published volumes of the federal censuses. We estimate the “riot effect” by both ordinary least squares and two-stage least squares. The second empirical approach uses individual-level census data from the Integrated Public Use Microdata Series for 1950, 1970, and 1980. The findings suggest that the riots had negative effects on blacks’ income and employment that were economically significant and that may have been larger in the long run (1960-1980) than in the short run (1960- 1970). We view these findings as suggestive rather than definitive for two reasons. First, the data are not detailed enough to identify the precise mechanisms at work. Second, the wave of riots may have had negative spillover effects to cities that did not experience severe riots; if so, we would tend to underestimate the riots’ overall effect.
Race and the Value of Owner-Occupied Housing, 1940-1990
The racial gap in the value of owner occupied housing has narrowed substantially since 1940, but this narrowing has not been even over time or across space. The 1970s stand out as an unusual decade in which the value gap did not narrow despite continued convergence in the observed characteristics of housing. A decline in the relative value of black-owned homes in central cities appears to have offset gains elsewhere during the 1970s, and this central city decline continued into the 1980s. In further exploration of the 1970s, we find evidence of a rising propensity for higher-income blacks to live in the suburbs. We also find a positive correlation between riots in the 1960s and widening of the value gap during the 1970s in a panel of cities.
"Race and the Value of Owner-Occupied Housing, 1940-1990"
The racial gap in the value of owner-occupied housing has narrowed substantially since 1940, but this narrowing has not been even over time or across space. The 1970s stand out as an unusual decade in which the value gap did not narrow despite continued convergence in the observed characteristics of housing. A decline in the relative value of black-owned homes in central cities appears to have offset gains elsewhere during the 1970s, and this central city decline continued into the 1980s. In further exploration of the 1970s, evidence is found of a rising propensity for higher-income blacks to live in the suburbs. A positive correlation between riots in the 1960s and widening of the value gap during the 1970s in a panel of cities also is found.
Global analysis of fragmentation functions for pions and kaons and their uncertainties
We present new sets of pion and kaon fragmentation functions obtained in NLO
combined analyses of single-inclusive hadron production in electron-positron
annihilation, proton-proton collisions, and deep-inelastic lepton-proton
scattering with either pions or kaons identified in the final state. At
variance with all previous fits, the present analyses take into account data
where hadrons of different electrical charge are identified, which allow to
discriminate quark from anti-quark fragmentation functions without the need of
non trivial flavor symmetry assumptions. The resulting sets are in good
agreement with all data analyzed, which cover a much wider kinematical range
than in previous fits. An extensive use of the Lagrange multiplier technique is
made in order to assess the uncertainties in the extraction of the
fragmentation functions and the synergy from the complementary data sets in our
global analysis.Comment: 28 pages, 25 figure
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