36,466 research outputs found
Determinants of Leverage and Agency problems
In this paper we empirically investigate the determinants of leverage and agency problems and we examine the relationships between leverage and agency problems. As in Titman and Wessels (1988) we use structural equations modeling with latent variables. In contrast to Titman and Wessels (1988), who employ data obtained from annual reports and capital markets, we use questionnaire data to measure firm characteristics. The questions concern the characteristics of the respondentsâ firms, including the presence of agency problems. We estimate the relations between these characteristics. The results confirm that the trade-off between tax advantages and bankruptcy costs determines leverage. We also find free cash flow and corporate governance characteristics as determinants of overinvestment. Despite findings that agency problems are present, direct relationships between leverage and four agency problems are absent.capital structure;agency costs
Option Formulas for Mean-Reverting Power Prices with Spikes
Electricity prices are known to be very volatile and subject tofrequent jumps due to system breakdown, demand shocks, and inelasticsupply. Appropriate pricing, portfolio, and risk management modelsshould incorporate these spikes. We develop a framework to priceEuropean-style options that are consistent with the possibility ofmarket spikes. The pricing framework is based on a regime jump modelthat disentangles mean-reversion from the spikes. In the model thespikes are truly time-specific events and therefore independent fromthe mean-reverting price process. This closely resembles thecharacteristics of electricity prices, as we show with Dutch APX spotprice data in the period January 2001 till June 2002. Thanks to theindependence of the two price processes in the model, we breakderivative prices down in a mean-reverting value and a spike value. Weuse this result to show how the model can be made consistent withforward prices in the market and present closed-form formulas forEuropean-style options.mean reversion;electricity price modelling;energy markets;option pricing;power spikes
From Skews to a Skewed-t
In this paper we present a new methodology to infer the implied risk-neutral distribution function from European-style options. We introduce a skewed version of the Student-t distribution, whose main advantage is that its shape depends on only four parameters, of which two directly control for the levels of skewness and kurtosis. We can thus easily vary parameters to compare different distributions and use the parameters as inputs to price other options. We explain the method, provide some empirical results and compare them with the results of alternative models. The results indicate that our model provides a better fit to market prices of options than the Shimko or implied tree models, and has a lower computation time than most other models. We conclude that the skewed Student-t method provides a good alternative for European-style options.implied distribution;implied volatility;options;skewness;student-t
Search for the magnetic field of the O7.5 III star xi Persei
Cyclical wind variability is an ubiquitous but as yet unexplained feature
among OB stars. The O7.5 III(n)((f)) star xi Persei is the brightest
representative of this class on the Northern hemisphere. As its prominent
cyclical wind properties vary on a rotational time scale (2 or 4 days) the star
has been already for a long time a serious magnetic candidate. As the cause of
this enigmatic behavior non-radial pulsations and/or a surface magnetic field
are suggested. We present a preliminary report on our attempts to detect a
magnetic field in this star with high-resolution measurements obtained with the
spectropolarimeter Narval at TBL, France during 2 observing runs of 5 nights in
2006 and 5 nights in 2007. Only upper limits could be obtained, even with the
longest possible exposure times. If the star hosts a magnetic field, its
surface strength should be less than about 300 G. This would still be enough to
disturb the stellar wind significantly. From our new data it seems that the
amplitude of the known non-radial pulsations has changed within less than a
year, which needs further investigation.Comment: 2 pages, 6 figures, contributed poster at IAU Symposium 259 "Cosmic
Magnetic Fields: from Planets, to Stars and Galaxies", Tenerife, Spain,
November 3-7, 200
Non score-dependency: Theory and assessment
Untrained listeners demonstrate implicit knowledge of syntactic patterns and principles. Untrained generative music ability, for example singing, humming, and whistling, is a largely unconscious or intuitive application of these patterns and principles. From the viewpoint of embodied cognition, listening to music should evoke an internal representation or motor image which, together with the perception of organized music, should form the basis of musical cognition. Indeed, that is what listeners demonstrate when they sing, hum, or whistle familiar and unfamiliar tunes or when they vocally or orally improvise continuations to interrupted phrases. Research on vocal improvisation using continuations sung to an interrupted musical phrase, has shown that oneâs cultural background influences the music generated. That should be the case for instrumentalists as well: when they play familiar or unfamiliar tunes by ear in different keys (transposition) or when they improvise variations, accompaniments, or continuations to interrupted phrases, the music they generate should reflect the same cognitive structures as their oral improvisations. This study is attempting to validate a test of (non) scoredependency that will enable assessment of the music studentâs implicit knowledge of these structures during performance on the principal instrument
A Look At Three Different Scenarios for Bulge Formation
In this paper, we present three qualitatively different scenarios for bulge
formation: a secular evolution model in which bulges form after disks and
undergo several central starbursts, a primordial collapse model in which bulges
and disks form simultaneously, and an early bulge formation model in which
bulges form prior to disks. We normalize our models to the local z=0
observations of de Jong & van der Kruit (1994) and Peletier & Balcells (1996)
and make comparisons with high redshift observations. We consider model
predictions relating directly to bulge-to-disk properties. As expected, smaller
bulge-to-disk ratios and bluer bulge colors are predicted by the secular
evolution model at all redshifts, although uncertainties in the data are
currently too large to differentiate strongly between the models.Comment: 19 pages, 6 figures, accepted for publication in the Astrophysical
Journa
Dynamics of rapidly rotating Bose-Einstein condensates in a harmonic plus quartic trap
A two-dimensional rapidly rotating Bose-Einstein condensate in a harmonic
plus quartic trap is expected to have unusual vortex states that do not occur
in a pure harmonic trap. At a critical rotation speed , a central
hole appears in the condensate, and at some faster rotation speed ,
the system undergoes a transition to a giant vortex state with pure
irrotational flow. Using a time-dependent variational analysis, we study the
behavior of an annular condensate with a single concentric ring of vortices.
The transition to a giant vortex state is investigated by comparing the energy
of the two equilibrium states (the ring of vortices and the giant vortex) and
also by studying the dynamical stability of small excitation modes of the ring
of vortices.Comment: 12pages, 4figure
A new catalog of photometric redshifts in the Hubble Deep Field
Using the newly available infrared images of the Hubble Deep Field in the J,
H, and K bands and an optimal photometric method, we have refined a technique
to estimate the redshifts of 1067 galaxies. A detailed comparison of our
results with the spectroscopic redshifts in those cases where the latter are
available shows that this technique gives very good results for bright enough
objects (AB(8140) < 26.0). From a study of the distribution of residuals
(Dz(rms)/(1+z) ~ 0.1 at all redshifts) we conclude that the observed errors are
mainly due to cosmic variance. This very important result allows for the
assessment of errors in quantities to be directly or indirectly measured from
the catalog. We present some of the statistical properties of the ensemble of
galaxies in the catalog, and finish by presenting a list of bright
high-redshift (z ~ 5) candidates extracted from our catalog, together with
recent spectroscopic redshift determinations confirming that two of them are at
z=5.34 and z=5.60.Comment: 28 pages, 12PS+4JPEG figures, aaspp style. Accepted for publication
in The Astrophysical Journal. The catalog, together with a clickable map of
the HDF, Tables 4 and 5 (HTML, LaTeX or ASCII format), and the figures, are
available at http://bat.phys.unsw.edu.au/~fsoto/hdfcat.htm
Aspects of competence-based education as footholds to improve the connectivity between learning in school and in the workplace
Recent developments in competence-based education have motivated institutions of vocational education and training (VET) to improve the links or connectivity between learning in school and learning in the workplace, which has been a problem for decades. In previous research, a theoretical framework describing the underlying aspects of competence-based education was developed. In this study, three aspects of this framework were used to analyse connectivity between learning in school and learning in the workplace. These aspects were: i) authenticity, ii) selfresponsibility, and iii) the role of the teacher as expert and coach. Three stakeholder groups (i.e., students, teachers, and workplace training supervisors) involved in secondary VET programs in the field of life sciences in the Netherlands were questioned on these aspects. Based on their interviews, it is concluded that these aspects provide information about the process of connectivity. Because stakeholder groups hold different conceptions of workplace learning and often do not communicate adequately about mutual responsibilities, the implementation of these aspects of competence-based education has not significantly improved the connectivity situation. Nevertheless, these aspects of competence-based education can guide stakeholder groups in making clearer agreements about mutual responsibilities, which may improve connectivity in the futur
- âŠ