7,049 research outputs found
Can Managers Time the Market? Evidence Using Repurchase Price Data
Little is known about the price firms pay for stock repurchases. Using a dataset of all U.S. repurchases from 2004 to 2011, we compare the actual average price paid monthly in a repurchase to the average market price for the same stock over various horizons. We find that firms repurchase stock at a significantly lower price than the average market price in all sample years. Less frequent repurchasers, firms that repurchase when insiders buy on their own account, and firms that experience low stock returns prior to the repurchase obtain significantly lower prices. After controlling for risk factors, repurchasing firms earn positive returns; infrequent repurchasers earn a significantly higher return up to three years following the actual repurchase.http://deepblue.lib.umich.edu/bitstream/2027.42/106638/1/1234_Dittmar.pd
A preliminary comparison between the SR-6 propeller noise in flight and in a wind tunnel
High speed turboprops offer an attractive candidate for aircraft because of their high propulsive efficiency. However, one of the possible problems associated with these propellers is their high noise level at cruise condition that may create a cabin environment problem. Models of these propellers were tested for acoustics in the 8 by 6-foot wind tunnel and on the Jet Star airplane. Comparisons between the airplane and wind tunnel data for the SR-6 propeller are shown. The comparison of maximum blade passing tone variation with helical tip Mach number between the tunnel and flight data was good when corrected to the same test conditions. Directivity comparisons also showed fairly good agreement. These good comparisons indicate that the wind tunnel is a viable location for measuring the blade passage tone noise of these propellers
Does Capital Market Myopia Affect Plant Productivity? Evidence from Going Private Transactions
One influential criticism of the stock market oriented U.S. financial system is that its excessive focus on short term quarterly earnings forces public firms to behave in a myopic manner. We hypothesize that if capital markets pressure listed firms to be myopic in a way that impacts efficiency, then going private (when myopia is eliminated) should cause U.S. firms to improve their establishment level productivity relative to a peer control groups of firms. We find no evidence that this is the case. Our key finding is that while there is evidence for substantial within-establishment increases in productivity after going private, there is little evidence of difference-in-differences efficiency gains relative to peer groups of establishments constructed to control for industry, age, size at the time of going private, and the endogeneity of the going private decision effects. Also, we do not find evidence that myopic markets lead to under-investment at the establishment level. On the contrary, we find that after going private, firms shrink capital and employment, and close plants more quickly, relative to peer groups. Our findings cast doubt on the view that public markets cause listed firms to make sub-optimal, productivity-decreasing choices, or under-invest at the establishment level.http://deepblue.lib.umich.edu/bitstream/2027.42/78529/1/1153_JSivadasan.pd
The Dynamics of Cash
Little is known about how firms manage cash policy over time. This paper fills this gap by examining if and how firms manage cash toward a target cash ratio. Estimating partial adjustment models of cash, we find that firms actively adjust their cash toward a target; however, the speed of adjustment is slow and there is large dispersion in the speed of adjustment across firms. We investigate the causes for this and find evidence consistent with the presence of adjustment costs. We also examine the implications of these results for previous interpretations of cross-sectional results. To do this, we simulate firmsâ cash paths allowing for costly adjustment and find that the emerging patterns question the interpretation of some of the standard results in the empirical cash literaturehttp://deepblue.lib.umich.edu/bitstream/2027.42/65067/1/1138_Duchin.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/65067/3/1138_Duchin_may.pd
Towards a Precise Parton Luminosity Determination at the CERN LHC
A new approach to determine the LHC luminosity is investigated. Instead of
employing the proton-proton luminosity measurement, we suggest to measure
directly the parton-parton luminosity. It is shown that the electron and muon
pseudorapidity distributions, originating from the decay of W+, W- and Z0
bosons produced at 14 TeV pp collisions (LHC), constrain the x distributions of
sea and valence quarks and antiquarks in the range from about 3 x 10**-4 to
about 10**-1 at a Q**2 of about 10**4 GeV**2. Furthermore, it is demonstrated
that, once the quark and antiquark structure functions are constrained from the
W+,W- and Z0 production dynamics, other quark-antiquark related scattering
processes at the LHC like q-qbar --> W+W- can be predicted accurately. Thus,
the lepton pseudorapidity distributions provide the key to a precise parton
luminosity monitor at the LHC, with accuracies of about +-1% compared to the so
far considered goal of +-5%.Comment: plain tex, 14 pages, 5 figure
b-quark decay in the collinear approximation
The semileptonic decay of a b-quark, b--> c l nu, is considered in the
relativistic limit where the decay products are approximately collinear.
Analytic results for the double differential lepton energy distributions are
given for finite charm-quark mass. Their use for the fast simulation of
isolated lepton backgrounds from heavy quark decays is discussed.Comment: 7 pages, 1 figure, submitted to Phys.Rev.
Gluon-induced W-boson pair production at the LHC
Pair production of W bosons constitutes an important background to Higgs
boson and new physics searches at the Large Hadron Collider LHC. We have
calculated the loop-induced gluon-fusion process gg -> W*W* -> leptons,
including intermediate light and heavy quarks and allowing for arbitrary
invariant masses of the W bosons. While formally of next-to-next-to-leading
order, the gg -> W*W* -> leptons process is enhanced by the large gluon flux at
the LHC and by experimental Higgs search cuts, and increases the
next-to-leading order WW background estimate for Higgs searches by about 30%.
We have extended our previous calculation to include the contribution from the
intermediate top-bottom massive quark loop and the Higgs signal process. We
provide updated results for cross sections and differential distributions and
study the interference between the different gluon scattering contributions. We
describe important analytical and numerical aspects of our calculation and
present the public GG2WW event generator.Comment: 20 pages, 4 figure
Next-to-leading order QCD predictions for associated production at the CERN Large Hadron Collider
We present the calculations of the complete next-to-leading order (NLO) QCD
corrections (including supersymmetric QCD) to the inclusive total cross
sections of the associated production processes in the Minimal
Supersymmetric Standard Model at the CERN Large Hadron Collider. Both the
dimensional regularization scheme and the dimensional reduction scheme are used
to organize the calculations which yield the same NLO rates. The NLO correction
can either enhance or reduce the total cross sections, but it generally
efficiently reduces the dependence of the total cross sections on the
renormalization/factorization scale. We also examine the uncertainty of the
total cross sections due to the parton distribution function uncertainties.Comment: 53 pages, 20 figures; the alpha_s in Eq.(70) is now evaluated at
M_SUSY scale, not the \mu_r scale; numerical results updated, typos
corrected; version to appear in PR
The Chandra X-ray Observatory Resolves the X-ray Morphology and Spectra of a Jet in PKS 0637-752
The core-dominated radio-loud quasar PKS 0637-752 (z = 0.654) was the first
celestial object observed with the Chandra X-ray Observatory, offering the
early surprise of the detection of a remarkable X-ray jet. Several observations
with a variety of detector configurations contribute to a total exposure time
with the Chandra Advanced CCD Imaging Spectrometer (ACIS; Garmire et al. 2000,
in preparation) of about 100ks. A spatial analysis of all the available X-ray
data, making use of Chandra's spatial resolving power of about 0.4 arcsec,
reveals a jet that extends about 10 arcsec to the west of the nucleus. At least
four X-ray knots are resolved along the jet, which contains about 5% of the
overall X-ray luminosity of the source. Previous observations of PKS 0637-752
in the radio band (Tingay et al. 1998) had identified a kpc-scale radio jet
extending to the West of the quasar. The X-ray and radio jets are similar in
shape, intensity distribution, and angular structure out to about 9 arcsec,
after which the X-ray brightness decreases more rapidly and the radio jet turns
abruptly to the north. The X-ray luminosity of the total source is log Lx ~
45.8 erg/s (2 - 10keV), and appears not to have changed since it was observed
with ASCA in November 1996. We present the results of fitting a variety of
emission models to the observed spectral distribution, comment on the
non-existence of emission lines recently reported in the ASCA observations of
PKS 0637-752, and briefly discuss plausible X-ray emission mechanisms.Comment: 24 pages, includes 8 figures, Accepted for publication in Ap
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