11,826 research outputs found
Fund managers - why the best might be the worst: On the evolutionary vigor of risk-seeking behavior
This article explores the influence of competitive conditions on the evolutionary fitness of different risk preferences. As a practical example, the professional competition between fund managers is considered. To explore how different settings of competition parameters, the exclusion rate and the exclusion interval, affect individual investment behavior, an evolutionary model based on a genetic algorithm is developed. The simulation experiments indicate that the influence of competitve conditions on investment behavior and attitudes towards risk is significant. What is alarming is that intense competitive pressure generates riskseeking behavior and undermines the predominance of the most skilled. --risk preferences,competition,genetic programming,fund managers,portfolio theory
The SIMRAND methodology: Theory and application for the simulation of research and development projects
A research and development (R&D) project often involves a number of decisions that must be made concerning which subset of systems or tasks are to be undertaken to achieve the goal of the R&D project. To help in this decision making, SIMRAND (SIMulation of Research ANd Development Projects) is a methodology for the selection of the optimal subset of systems or tasks to be undertaken on an R&D project. Using alternative networks, the SIMRAND methodology models the alternative subsets of systems or tasks under consideration. Each path through an alternative network represents one way of satisfying the project goals. Equations are developed that relate the system or task variables to the measure of reference. Uncertainty is incorporated by treating the variables of the equations probabilistically as random variables, with cumulative distribution functions assessed by technical experts. Analytical techniques of probability theory are used to reduce the complexity of the alternative networks. Cardinal utility functions over the measure of preference are assessed for the decision makers. A run of the SIMRAND Computer I Program combines, in a Monte Carlo simulation model, the network structure, the equations, the cumulative distribution functions, and the utility functions
Portfolio selection models: A review and new directions
Modern Portfolio Theory (MPT) is based upon the classical Markowitz model which uses variance as a risk measure. A generalization of this approach leads to mean-risk models, in which a return distribution is characterized by the expected value of return (desired to be large) and a risk value (desired to be kept small). Portfolio choice is made by solving an optimization problem, in which the portfolio risk is minimized and a desired level of expected return is specified as a constraint. The need to penalize different undesirable aspects of the return distribution led to the proposal of alternative risk measures, notably those penalizing only the downside part (adverse) and not the upside (potential). The downside risk considerations constitute the basis of the Post Modern Portfolio Theory (PMPT). Examples of such risk measures are lower partial moments, Value-at-Risk (VaR) and Conditional Value-at-Risk (CVaR). We revisit these risk measures and the resulting mean-risk models. We discuss alternative models for portfolio selection, their choice criteria and the evolution of MPT to PMPT which incorporates: utility maximization and stochastic dominance
Data-driven Approximation of Distributionally Robust Chance Constraints using Bayesian Credible Intervals
The non-convexity and intractability of distributionally robust chance
constraints make them challenging to cope with. From a data-driven perspective,
we propose formulating it as a robust optimization problem to ensure that the
distributionally robust chance constraint is satisfied with high probability.
To incorporate available data and prior distribution knowledge, we construct
ambiguity sets for the distributionally robust chance constraint using Bayesian
credible intervals. We establish the congruent relationship between the
ambiguity set in Bayesian distributionally robust chance constraints and the
uncertainty set in a specific robust optimization. In contrast to most existent
uncertainty set construction methods which are only applicable for particular
settings, our approach provides a unified framework for constructing
uncertainty sets under different marginal distribution assumptions, thus making
it more flexible and widely applicable. Additionally, under the concavity
assumption, our method provides strong finite sample probability guarantees for
optimal solutions. The practicality and effectiveness of our approach are
illustrated with numerical experiments on portfolio management and queuing
system problems. Overall, our approach offers a promising solution to
distributionally robust chance constrained problems and has potential
applications in other fields
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