15,516 research outputs found
Empire-Builders and Shirkers: Investment, Firm Performance, and Managerial Incentives
Do firms systematically over- or underinvest as a result of agency problems? We develop a contracting model between shareholders and managers in which managers have private benefits or private costs of investment. Managers overinvest when they have private benefits and underinvest when they have private costs. Optimal incentive contracts mitigate the over- or underinvestment problem. We derive comparative static predictions for the equilibrium relationships between incentives from compensation, investment, and firm performance for both cases. The relationship between firm performance and managerial incentives, in isolation, is insufficient to identify whether managers have private benefits or private costs of investment. In order to identify whether managers have private benefits or costs, we estimate the joint relationships between incentives and firm performance and between incentives and investment. Our empirical results show that both firm performance and investment are increasing in managerial incentives. These results are consistent with managers having private costs of investment. We find no support for overinvestment based on private benefits.
Performance Incentives Within Firms: The Effect of Managerial Responsibility
Empirical research on executive compensation has focused almost exclusively on the incentives provided to chief executive officers. However, firms are run by teams of managers, and a theory of the firm should also explain the distribution of incentives and responsibilities for other members of the top management team. An extension of the standard principal-agent model to allow for multiple signals of effort predicts that executives who have other, more precise signals of their effort than firm performance will have compensation that is less sensitive to the overall performance of the firm. We test this prediction in a comprehensive panel dataset of executives at large corporations by comparing executives with explicit divisional responsibilities to those with broad oversight authority over the firm and to CEOs. Controlling for executive fixed effects and the level of compensation, we find that CEOs have pay-performance incentives that are 1.26 per thousand higher than those of executives with divisional responsibility. The aggregate pay-performance sensitivity of the top management team is quite substantial, at $30.24 per thousand dollar increase in shareholder wealth for the median firm in our sample. Our work sheds light on the alignment of responsibility and incentives within firms and suggests that the principal-agent model provides an appropriate characterization of the internal organization of the firm.
Event-by-Event Search for Charged Neutral Fluctuations in Pb - Pb Collisions at 158-A-GeV
Results from the analysis of data obtained from the WA98 experiment at the
CERN SPS have been presented. Some events have been filtered which show photon
excess in limited zones within the overlap region of the charged
particle and photon multiplicity detectors.Comment: 6 pages, 4 figure
Radiative rates and electron impact excitation rates for transitions in He II
We report calculations of energy levels, radiative rates, collision
strengths, and effective collision strengths for transitions among the lowest
25 levels of the n <= 5 configurations of He~II. The general-purpose
relativistic atomic structure package (GRASP) and Dirac atomic R-matrix code
(DARC) are adopted for the calculations. Radiative rates, oscillator strengths,
and line strengths are reported for all electric dipole (E1), magnetic dipole
(M1), electric quadrupole (E2), and magnetic quadrupole (M2) transitions among
the 25 levels. Furthermore, collision strengths and effective collision
strengths are listed for all 300 transitions among the above 25 levels over a
wide energy (temperature) range up to 9 Ryd (10**5.4 K). Comparisons are made
with earlier available results and the accuracy of the data is assessed.Comment: 30 pages of text including 12 figures and 5 Tables will appear in
ATOMS 5 (2017
Electron Impact Excitation Cross Sections for Hydrogen-Like Ions
We present cross sections for electron-impact-induced transitions n --> n' in
hydrogen-like ions C 5+, Ne 9+, Al 12+, and Ar 17+. The cross sections are
computed by Coulomb-Born with exchange and normalization (CBE) method for all
transitions with n < n' < 7 and by convergent close-coupling (CCC) method for
transitions with n 2s and 1s
--> 2p are presented as well. The CCC and CBE cross sections agree to better
than 10% with each other and with earlier close-coupling results (available for
transition 1 --> 2 only). Analytical expression for n --> n' cross sections and
semiempirical formulae are discussed.Comment: RevTeX, 5 pages, 13 PostScript figures, submitted to Phys. Rev.
Structure of confined laminar spray diffusion flames: Numerical investigation
The structure of confined laminar spray diffusion flames is investigated numerically by solving the gas-phase conservation equations for mass species, continuity, momentum, and energy and the liquid-phase equations for droplet position, velocity, size, and temperature. A one-step global reaction scheme along with six equilibrium reactions are employed to model the flame chemistry. Monodisperse as well as polydisperse sprays are considered. The numerical results demonstrate that liquid spray flames substantially differ from gaseous flames in their structure, i.e., temperature, concentration, and velocity fields, shape, and dimensions under the same conditions. Spray flames are predicted to be taller and narrower than their counterpart gaseous ones and their shapes are almost cylindrical. This is in agreement with experimental observations. The numerical computations also show that the use of the equilibrium reactions with the one-step reaction scheme decreases the flame temperature compared to the one-step reaction scheme without the equilibrium reactions and more importantly increases the surface area of the flame zone due to a phenomenon termed 'equilibrium broadening.' The spray flames also possess a finite thickness with minimal overlap of the fuel and oxygen species. A case for which a fuel-mixture consisting of 20 to 80 percent gas-liquid by mass is introduced into the combustor is also investigated and compared with predictions using only gaseous or liquid fuel
Empirical Evaluation of the Parallel Distribution Sweeping Framework on Multicore Architectures
In this paper, we perform an empirical evaluation of the Parallel External
Memory (PEM) model in the context of geometric problems. In particular, we
implement the parallel distribution sweeping framework of Ajwani, Sitchinava
and Zeh to solve batched 1-dimensional stabbing max problem. While modern
processors consist of sophisticated memory systems (multiple levels of caches,
set associativity, TLB, prefetching), we empirically show that algorithms
designed in simple models, that focus on minimizing the I/O transfers between
shared memory and single level cache, can lead to efficient software on current
multicore architectures. Our implementation exhibits significantly fewer
accesses to slow DRAM and, therefore, outperforms traditional approaches based
on plane sweep and two-way divide and conquer.Comment: Longer version of ESA'13 pape
An investigation of Fe XV emission lines in solar flare spectra
Previously, large discrepancies have been found between theory and
observation for Fe XV emission line ratios in solar flare spectra covering the
224-327 A wavelength range, obtained by the Naval Research Laboratory's S082A
instrument on board Skylab. These discrepancies have been attributed to either
errors in the adopted atomic data or the presence of additional atomic
processes not included in the modelling, such as fluorescence. However our
analysis of these plus other S082A flare observations (the latter containing Fe
XV transitions between 321-482 A), performed using the most recent Fe XV atomic
physics calculations in conjunction with a CHIANTI synthetic flare spectrum,
indicate that blending of the lines is primarily responsible for the
discrepancies. As a result, most Fe XV lines cannot be employed as electron
density diagnostics for solar flares, at least at the spectral resolution of
S082A and similar instruments (i.e. ~ 0.1 A). An exception is the intensity
ratio I(321.8 A)/I(327.0 A), which appears to provide good estimates of the
electron density at this spectral resolution.Comment: 6 pages, 3 figures, Astronomy & Astrophysics, in pres
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