891 research outputs found

    Teaching about teaching and instruction on instruction: A challenge for health sciences library education

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    Objective: This is a review of the master's-level curricula of the fifty-eight America Library Association-accredited library and information science programs and iSchools for evidence of coursework and content related to library instruction. Special emphasis is placed on the schools and programs that also offer coursework in medical or health sciences librarianship. Methods: Fifty-eight school and program websites were reviewed. Course titles and course descriptions for seventy-three separate classes were analyzed. Twenty-three syllabi were examined. Results: All North American library education programs offer at least one course in the general area of library instruction; some programs offer multiple courses. No courses on instruction, however, are focused directly on the specialized area of health sciences librarianship. Conclusions: Master's degree students can take appropriate classes on library instruction, but the medical library profession needs to offer continuing education opportunities for practitioners who want to have specific instruction for the specialized world of the health sciences

    Cartesianism and its Feminist Promise and Limits: The Case of Mary Astell

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    In this paper, I consider Mary Astell's contributions to the history of feminism, noting her grounding in and departure from Cartesianism and its relation to women

    Calibration Risk for Exotic Options

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    Option pricing models are calibrated to market data of plain vanillas by minimization of an error functional. From the economic viewpoint, there are several possibilities to measure the error between the market and the model. These different specifications of the error give rise to different sets of calibrated model parameters and the resulting prices of exotic options vary significantly. These price differences often exceed the usual profit margin of exotic options. We provide evidence for this calibration risk in a time series of DAX implied volatility surfaces from April 2003 to March 2004. We analyze in the Heston and in the Bates model factors influencing these price differences of exotic options and finally recommend an error functional. Moreover, we determine the model risk of these two stochastic volatility models for the time series and consider its relation to calibration risk.calibration risk, calibration, model risk, Heston model, Bates model, barrier option, cliquet option

    Conditional and Dynamic Convex Risk Measures

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    We extend the definition of a convex risk measure to a conditional framework where additional information is available. We characterize these risk measures through the associated acceptance sets and prove a representation result in terms of conditional expectations. As an example we consider the class of conditional entropic risk measures. A new regularity property of conditional risk measures is defined and discussed. Finally we introduce the concept of a dynamic convex risk measure as a family of successive conditional convex risk measures and characterize those satisfying some natural time consistency properties.Conditional convex risk measure, robust representation, regularity, entropic risk measure, dynamic convex risk measure, time consistency

    Forecasting the Term Structure of Variance Swaps

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    Recently, Diebold and Li (2003) obtained good forecasting results for yield curves in a reparametrized Nelson-Siegel framework. We analyze similar modeling approaches for price curves of variance swaps that serve nowadays as hedging instruments for options on realized variance. We consider the popular Heston model, reparametrize its variance swap price formula and model the entire variance swap curves by two exponential factors whose loadings evolve dynamically on a weekly basis. Generalizing this approach we consider a reparametrization of the three-dimensional Nelson-Siegel factor model. We show that these factors can be interpreted as level, slope and curvature and how they can be estimated directly from characteristic points of the curves. Moreover, we analyze a semiparametric factor model. Estimating autoregressive models for the factor loadings we get termstructure forecasts that we compare in addition to the random walk and the static Heston model that is often used in industry. In contrast to the results of Diebold and Li (2003) on yield curves, no model produces better forecasts of variance swap curves than the random walk but forecasting the Heston model improves the popular static Heston model. Moreover, the Heston model is better than the flexible semiparametric approach that outperforms the Nelson-Siegel model.Term structure, Variance swap curve, Heston model, Nelson-Siegel curve, Semiparametric factor model

    Calibration Design of Implied Volatility Surfaces

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    The calibration of option pricing models leads to the minimization of an error functional. We show that its usual specification as a root mean squared error implies fluctuating exotics prices and possibly wrong prices. We propose a simple and natural method to overcome these problems, illustrate drawbacks of the usual approach and show advantages of our method. To this end, we calibrate the Heston model to a time series of DAX implied volatility surfaces and then price cliquet options.calibration, data design, implied volatility surface, Heston model, cliquet option

    Empirical Pricing Kernels and Investor Preferences

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    This paper analyzes empirical market utility functions and pricing kernels derived from the DAX and DAX option data for three market regimes. A consistent parametric framework of stochastic volatility is used. All empirical market utility functions show a region of risk proclivity that is reproduced by adopting the hypothesis of heterogeneous individual investors whose utility functions have a switching point between bullish and bearish attitudes. The inverse problem of finding the distribution of individual switching points is formulated in the space of stock returns by discretization as a quadratic optimization problem. The resulting distributions vary over time and correspond to different market regimes.Utility function, Pricing Kernel, Behavioral Finance, Risk Aversion, Risk Proclivity, Heston model.

    Descartes on the Theory of Life and Methodology in the Life Sciences

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    As a practicing life scientist, Descartes must have a theory of what it means to be a living being. In this paper, I provide an account of what his theoretical conception of living bodies must be. I then show that this conception might well run afoul of his rejection of final causal explanations in natural philosophy. Nonetheless, I show how Descartes might have made use of such explanations as merely hypothetical, even though he explicitly blocks this move. I conclude by suggesting that there is no reason for him to have blocked the use of hypothetical final causes in this way

    Hilbert's "Verunglueckter Beweis," the first epsilon theorem, and consistency proofs

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    In the 1920s, Ackermann and von Neumann, in pursuit of Hilbert's Programme, were working on consistency proofs for arithmetical systems. One proposed method of giving such proofs is Hilbert's epsilon-substitution method. There was, however, a second approach which was not reflected in the publications of the Hilbert school in the 1920s, and which is a direct precursor of Hilbert's first epsilon theorem and a certain 'general consistency result' due to Bernays. An analysis of the form of this so-called 'failed proof' sheds further light on an interpretation of Hilbert's Programme as an instrumentalist enterprise with the aim of showing that whenever a `real' proposition can be proved by 'ideal' means, it can also be proved by 'real', finitary means.Comment: 18 pages, final versio
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