1,721,111 research outputs found
Technological Choice under Organizational Diseconomies of Scale
Full text linkWith adverse selection, diseconomies of scale associated with hierarchies may induce the implementation of a second-best technology. This occurs whenever rents to lower tiers of the hierarchy increase faster than total surplus. This is more likely with longer hierarchies.Adverse Selection, Hierarchies, Technology
Governance: Who Controls Matters
Full text linkIn this paper, we provide an outlook for further research on the topic of governance. We review four different approaches on the theory of the firm and discuss implications for governance, namely; nexus of contracts / agency theory, property rights / incomplete contracts, adaptation, and nexus of specific investments.governance, property rights, adaptation, nexus of contracts
On the Difficulty to Design Arabic E-learning System in Statistics
Full text linkIn this paper, we present a case study, which describe the development of the Statistic e-learning-course in Arabic language –``Arabic MM*STAT´´. The basic frame forthis E-book, the system MM*STAT was developed at the School for Business and Economics of Humboldt-Universität zu Berlin. Arabic MM*STAT uses a HTML - based filing card structure. We discuss the difficulties of the implementation of such a system in to the standard WWW formats and present the solutions needed for Arab educational institutions and the Arabic user. Those solutions are consistent with the Arabic language, and include the modern trend in the e-learning environment.electronic books, Arabtex, MM*STAT, Statistical software
Exploratory Graphics of a Financial Dataset
Full text linkcompany rating, default probability, support vector machines, colour coding
Adaptive Simulation Algorithms for Pricing American and Bermudian Options by Local Analysis of Financial Market
Full text linkHere we develop an approach for efficient pricing discrete-time American and Bermudan options which employs the fact that such options are equivalent to the European ones with a consumption, combined with analysis of the market model over a small number of steps ahead. This approach allows constructing both upper and low bounds for the true price by Monte Carlo simulations. An adaptive choice of local low bounds and use of the kernel interpolation technique enhance efficiency of the whole procedure, which is supported by numerical experiments.American and Bermudan options, Lower and Upper bounds, Monte Carlo simulation, Variance reduction
Discounted Optimal Stopping for Maxima in Diffusion Models with Finite Horizon
Full text linkWe present a solution to some discounted optimal stopping problem for the maximum of a geometric Brownian motion on a finite time interval. The method of proof is based on reducing the initial optimal stopping problem with the continuation region determined by an increasing continuous boundary surface to a parabolic free-boundary problem. Using the change-of-variable formula with local time on surfaces we show that the optimal boundary can be characterized as a unique solution of a nonlinear integral equation. The result can be interpreted as pricing American fixed-strike lookback option in a diffusion model with finite time horizon.Discounted optimal stopping problem, finite horizon, geometric Brownian motion, maximum process, parabolic free-boundary problem, smooth fit, normal reflection, a nonlinear Volterra integral equation of the second kind, boundary surface, a change-of-variable formula with local time on surfaces, American lookback option problem
Spectral calibration of exponential Lévy Models [2]
Full text linkThe calibration of financial models has become rather important topic in recent years mainly because of the need to price increasingly complex options in a consistent way. The choice of the underlying model is crucial for the good performance of any calibration procedure. Recent empirical evidences suggest that more complex models taking into account such phenomenons as jumps in the stock prices, smiles in implied volatilities and so on should be considered. Among most popular such models are Levy ones which are on the one hand able to produce complex behavior of the stock time series including jumps, heavy tails and on other hand remain tractable with respect to option pricing. The work on calibration methods for financial models based on Lévy processes has mainly focused on certain parametrisations of the underlying Lévy process with the notable exception of Cont and Tankov (2004). Since the characteristic triplet of a Lévy process is a priori an infinite-dimensional object, the parametric approach is always exposed to the problem of misspecification, in particular when there is no inherent economic foundation of the parameters and they are only used to generate different shapes of possible jump distributions. In this work we propose and test a non-parametric calibration algorithm which is based on the inversion of the explicit pricing formula via Fourier transforms and a regularisation in the spectral domain. Using the Fast Fourier Transformation, the procedure is fast, easy to implement and yields good results in simulations in view of the severe ill-posedness of the underlying inverse problem.European option, jump diffusion, minimax rates, severely ill-posed, nonlinear inverse problem, spectral cut-off
Tail Conditional Expectation for vector-valued Risks
Full text linkIn his paper we introduce a quantile-based risk measure for multivariate financial positions "the vector-valued Tail-conditional-expectation (TCE)". We adopt the framework proposed by Jouini, Meddeb, and Touzi [9] to deal with multi-assets portfolios when one accounts for frictions in the financial market. In this framework, the space of risks formed by essentially bounded random vectors, is endowed with some partial vector preorder >= accounting for market frictions. In a first step we provide a definition for quantiles of vector-valued risks which is compatible with the preorder >=. The TCE is then introduced as a natural extension of the "classical" real-valued tail-conditional-expectation. Our main result states that for continuous distributions TCE is equal to a coherent vector-valued risk measure. We also provide a numerical algorithm for computing vector-valued quantiles and TCE.Risk measures, vector-valued risk measures, coherent risk-measures, quantiles, tail-conditional-expectation
Spectral calibration of exponential Lévy Models [1]
Full text linkWe investigate the problem of calibrating an exponential Lévy model based on market prices of vanilla options. We show that this inverse problem is in general severely ill-posed and we derive exact minimax rates of convergence. The estimation procedure we propose is based on the explicit inversion of the option price formula in the spectral domain and a cut-off scheme for high frequencies as regularisation.European option, jump diffusion, minimax rates, severely ill-posed, nonlinear inverse problem, spectral cut-off
A Control Approach to Robust Utility Maximization with Logarithmic Utility and Time-Consistent Penalties
Full text linkWe propose a stochastic control approach to the dynamic maximization of robust utility functionals that are defined in terms of logarithmic utility and a dynamically consistent convex risk measure. The underlying market is modeled by a diffusion process whose coefficients are driven by an external stochastic factor process. In particular, the market model is incomplete. Our main results give conditions on the minimal penalty function of the robust utility functional under which the value function of our problem can be identified with the unique classical solution of a quasilinear PDE within a class of functions satisfying certain growth conditions. The fact that we obtain classical solutions rather than viscosity solutions is important for the use of numerical algorithms, whose applicability is demonstrated in examples.Optimal investment, model uncertainty, incomplete markets, stochastic volatility, coherent risk measure, convex risk measure, optimal control, convex duality
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