1,446 research outputs found
The Impact of Public Guarantees on Bank Risk Taking: Evidence from a Natural Experiment
In 2001, government guarantees for savings banks in Germany were removed following a law suit. We use this natural experiment to examine the effect of government guarantees on bank risk taking, using a large data set of matched bank/borrower information. The results suggest that banks whose government guarantee was removed reduced credit risk by cutting off the riskiest borrowers from credit. At the same time, the banks also increased interest rates on their remaining borrowers. The effects are economically large: the Z-Score of average borrowers increased by 7% and the average loan size declined by 13%. Remaining borrowers paid 57 basis points higher interest rates, despite their higher quality. Using a difference-in-differences approach we show that the effect is larger for banks that ex ante benefitted more from the guarantee. We show that both the credit quality of new customers improved (screening) and that the loans of existing riskier borrowers were less likely to be renewed (monitoring), after the removal of public guarantees. Public guarantees seem to be associated with substantial moral hazard effects.banking;public guarantees;credit risk;moral hazard
Beyond XSPEC: Towards Highly Configurable Analysis
We present a quantitative comparison between software features of the defacto
standard X-ray spectral analysis tool, XSPEC, and ISIS, the Interactive
Spectral Interpretation System. Our emphasis is on customized analysis, with
ISIS offered as a strong example of configurable software. While noting that
XSPEC has been of immense value to astronomers, and that its scientific core is
moderately extensible--most commonly via the inclusion of user contributed
"local models"--we identify a series of limitations with its use beyond
conventional spectral modeling. We argue that from the viewpoint of the
astronomical user, the XSPEC internal structure presents a Black Box Problem,
with many of its important features hidden from the top-level interface, thus
discouraging user customization. Drawing from examples in custom modeling,
numerical analysis, parallel computation, visualization, data management, and
automated code generation, we show how a numerically scriptable, modular, and
extensible analysis platform such as ISIS facilitates many forms of advanced
astrophysical inquiry.Comment: Accepted by PASP, for July 2008 (15 pages
Quantum Monte Carlo Study of Strongly Correlated Electrons: Cellular Dynamical Mean-Field Theory
We study the Hubbard model using the Cellular Dynamical Mean-Field Theory
(CDMFT) with quantum Monte Carlo (QMC) simulations. We present the algorithmic
details of CDMFT with the Hirsch-Fye QMC method for the solution of the
self-consistently embedded quantum cluster problem. We use the one- and
two-dimensional half-filled Hubbard model to gauge the performance of CDMFT+QMC
particularly for small clusters by comparing with the exact results and also
with other quantum cluster methods. We calculate single-particle Green's
functions and self-energies on small clusters to study their size dependence in
one- and two-dimensions.Comment: 14 pages, 18 figure
Therapie bei Progression und Rezidiv des Ovarialkarzinoms
Secondary surgery after failure of primary treatment is a promising and reasonable option only for patients with a relapse-free interval of at least 6-12 months who should have ideally achieved a tumor-free status after primary therapy. As after primary surgery, size of residual tumor is the most significant predictor of survival after secondary surgery. Even in the case of multiple tumor sites, complete removal of the tumor can be achieved in nearly 30% of the patients. Treatment results are much better in specialized oncology centers with optimal interdisciplinary cooperation compared with smaller institutions. Chemotherapy can be used both for consolidation after successful secondary surgery and for palliation in patients with inoperable recurrent disease. Since paclitaxel has been integrated into first-line chemotherapy, there is no defined standard for second-line chemotherapy. Several cytotoxic agents have shown moderate activity in this setting, including treosulfan, epirubicin, and newer agents such as topotecan, gemcitabine, vinorelbine, and PEG(polyethylene glycol)-liposomal doxorubicin. Thus, the German Arbeitsgemeinschaft Gynakologische Onkologie (AGO) has initiated several randomized studies in patients with recurrent ovarian cancer in order to define new standards for second-line chemotherapy
Learning from the Success of MPI
The Message Passing Interface (MPI) has been extremely successful as a
portable way to program high-performance parallel computers. This success has
occurred in spite of the view of many that message passing is difficult and
that other approaches, including automatic parallelization and directive-based
parallelism, are easier to use. This paper argues that MPI has succeeded
because it addresses all of the important issues in providing a parallel
programming model.Comment: 12 pages, 1 figur
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