934 research outputs found
The Education Premium in Canada and the United States
It is well known that in the United States the education premium--the ratio of the earnings of university graduates to the earnings of high school graduates--has risen sharply in the last twenty years. Some Canadian economists and policy makers presume the same fact holds in Canada. Since so much of modern growth theory and micro and macroecomomic policy turns on the education premium, it is important for social scientists and policy makers to know what has actually happened to the education premium. This paper argues that on the basis of available evidence over the last twenty years the premium has been constant or has fallen in Canada.education premium
WAGES in CANADA: SCF, SLID, LFS and the Skill Premium
For the years 1981 to 1997 the Survey of Consumer Finances served as the main source of information about the earnings of individuals, households and families. The Survey of Labour Income Dynamics, begun in 1993, was intended to replace and to improve upon the SCF. The Labour Force Survey which began releasing earnings information in 1997 (the last year of the SCF) is a second alternative for extending historical earnings data to the present day. This paper examines the extent to which either of these two surveys can be used to extend the SCF series to more recent times. Neither survey comes off as satisfactory in all respects as an extension of SCF earnings data though if one's purposes are more limited, such as studying the education premium, then merging results from the SCF and SLID seems a reasonable way to proceed. It is not possible here to assess the ability of SLID or LFS to extend the SCF for other applications. But this method could easily be adapted to address other similar questions.earnings; education premium; SLID; SCF
Cohort, Year and Age Effects in Canadian Wage Data
We use Canadian SCFs 1971-1993 to study the wages of full-time, full-year male and female workers. Median real wages of 24-year-old males without a university degree fell by 25% between 1978 and 1993. For 24-year-old females the decline was more modest and reversed in 1987, but real wages in 1993 were still significantly lower than they were in 1978. We investigate whether these changes are permanent “cohort” effects or more temporary “year” effects. Graphs of median wages against year and age indicate some periods where year effects are more prominent than cohort effects and other periods where the reverse is true. We then compare the results from two models, one assigning the trends to year effects, the other assigning them to cohort effects, and use these models to produce real wage projections.
The Education Premium in Canada and the United States
It is well known that in the United States the education premium--the ratio of the earnings of university graduates to the earnings of high school graduates--has risen sharply in the last twenty years. Some Canadian economists and policy makers presume the same fact holds in Canada. Since so much of modern growth theory and micro and macroecomomic policy turns on the education premium, it is important for social scientists and policy makers to know what has actually happened to the education premium. This paper argues that on the basis of available evidence over the last twenty years the premium has been constant or has fallen in Canada.education premium
Physical conditions in the primitive solar nebula
Physical conditions for model of primitive solar nebul
Pneumococcal conjugate vaccine given shortly after birth stimulates effective antibody concentrations and primes immunological memory for sustained infant protection.
BACKGROUND: In developing countries, newborn immunization with pneumococcal conjugate vaccines (PCVs) could protect young infants who are at high risk of invasive pneumococcal disease (IPD) but might lead to immune tolerance. METHODS: In a randomized trial, young infants received 7-valent PCV at 6, 10, and 14 weeks (Expanded Programme on Immunization [EPI] group) or 0, 10, and 14 weeks (newborn group). Safety was monitored actively at 2-7 days and then passively. Serum samples obtained at birth and 6, 10, 14, 18, 36, and 37 weeks were assayed by enzyme-linked immunosorbent assay for anticapsular immunoglobulin G concentration and avidity. Infants were boosted with either 7-valent PCV or one-fifth dose of pneumococcal polysaccharide vaccine at 36 weeks. Nasopharyngeal swab samples were obtained at 18 and 36 weeks. RESULTS: Three-hundred neonates and young infants were enrolled. Newborn vaccination was well tolerated. Adverse events occurred equally in each group; none was related to immunization. One infant, immunized at birth, died of unrelated neonatal sepsis. At 18 weeks, protective concentrations (≥0.35 μg/mL) were achieved against each serotype by ≥87% of infants with no significant differences between groups. Geometric mean concentrations were higher in the EPI group for serotypes 4, 9V, 18C, and 19F at 18 weeks and for serotype 4 at 36 weeks. Avidity was greater in the newborn group for serotypes 4, 6B, and 19F at 18 weeks and for serotype 19F at 36 weeks. Booster responses and vaccine-type/nonvaccine-type carriage prevalence did not differ between groups. CONCLUSIONS: PCV was safe, immunogenic, and primed for memory when given at birth. There was no evidence of immune tolerance. Vaccination beginning at birth offers an alternative to control IPD in vulnerable young infants
QSOs Associated with Messier 82
The starburst / AGN galaxy M82 was studied by Dahlem, Weaver and Heckman
using X-ray data from ROSAT and ASCA, as part of their X-ray survey of edge-on
starburst galaxies. They found seventeen unresolved hard-X-ray sources around
M82, in addition to its strong nuclear source, and other X-rays within the main
body of M82. We have measured optical point sources at these positions, and
have obtained redshifts of six candidates at the Keck I 10-m telescope, using
the low-resolution imaging spectrograph (LRIS). All six are highly compact
optical and X-ray objects with redshifts ranging from 0.111 to 1.086. They all
show emission lines. The three with the highest redshifts are clearly QSOs. The
others with lower redshifts may either be QSOs or compact emission-line
galaxies. In addition to these six there are nine QSOs lying very close to M82
which were discovered many years ago. There is no difference between optical
spectra of these latter QSOs, only two of which are known to be X-ray sources,
and the X-ray emitting QSOs. The redshifts of all fifteen range between 0.111
and 2.05. The large number of QSOs and their apparent association with ejected
matter from M82 suggest that they are physically associated with the galaxy,
and have large intrinsic redshift components. If this is correct, the absolute
magnitudes lie in the range -8 < M_v < -10. Also we speculate that the luminous
variable X-ray source which has been detected by Chandra in the main body of
M82 some 9 arcseconds from the center is another QSO in the process of ejection
from the nucleus, and propose some observational tests of this hypothesis.Comment: 16 pages aastex, 3 eps figures, accepted for publication on Ap
The Distribution of Redshifts in New Samples of Quasi-stellar Objects
Two new samples of QSOs have been constructed from recent surveys to test the
hypothesis that the redshift distribution of bright QSOs is periodic in
. The first of these comprises 57 different redshifts among all
known close pairs or multiple QSOs, with image separations 10\arcsec,
and the second consists of 39 QSOs selected through their X-ray emission and
their proximity to bright comparatively nearby active galaxies. The redshift
distributions of the samples are found to exhibit distinct peaks with a
periodic separation of in identical to that claimed
in earlier samples but now extended out to higher redshift peaks and 4.47, predicted by the formula but never seen before. The periodicity
is also seen in a third sample, the 78 QSOs of the 3C and 3CR catalogues. It is
present in these three datasets at an overall significance level -
, and appears not to be explicable by spectroscopic or similar
selection effects. Possible interpretations are briefly discussed.Comment: submitted for publication in the Astronomical Journal, 15 figure
Ejection of Matter and Energy from NGC 4258
It has been claimed that the megamaser observations of the nucleus of NGC
4258 show that a massive black hole is present in its center (Miyoshi et al.
1995, Greenhill et al. 1995). We show that the evidence of ejection of gas,
radio plasma, and X-ray emitting QSOs from this nucleus all show that the
ejection is coming from the center in a curving flow within a cone with angle
~40 degrees, centered at P.A. 100 degrees. This is close to the direction in
which the velocities from the megamaser have been measured, so that the
evidence taken as a whole suggests that the masering gas also is being ejected
in the same direction at velocities +/- 900 km/sec and not rotating about a
massive black hole. Thus it does not provide evidence for a black hole in the
center.
Subject headings: galaxies: nuclei: individual (NGC 4258) -- black holes --
masersComment: 7 pages, 1 Figure, LaTex using epsf.tex, submitted to Ap.J.Letter
Status of the profession
The number of astronomers has grown by about 40 percent over the past decade. The number of astronomers with jobs in industry, or with long-term, non-tenured, jobs has increased dramatically compared with traditional faculty positions. The increase in the number of astronomers and the declining share of the NSF budget going to astronomy has led to extreme difficulties in the NSF grant program and in support of the National Observatories. In 1989, direct NASA support of astronomers through the grants program exceeds that of NSF, although the total of the NSF grants program over decade far exceeds that of NASA. Access to major new telescopes will be important issue for the 1990s. US astronomers, who once had a monopoly on telescopes larger than 3 meters, will, by the year 2000, have access to just half of the world's optical telescope area
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