A Monte Carlo simulation was used to generate data for a comparison of five robust regression estimation methods with ordinary least squares (OLS) under 36 different outlier data configurations. Two of the robust estimators, Least Absolute Value (LAV) estimation and MM estimation, are...

As disease spreads through a population, scientists want to know who gets sick, how bestto prevent a large outbreak, and if an epidemic may occur. For many years, mathematicians usedmodels to approximate answers to these questions; however, these older models used simplifyingassumptions about...

For seventy years ecologists have debated to what extent competition affects the composition of ecological communities. At one extreme, species have been proposed to assemble independently of each other, while at the other extreme, competition and other interspecific interactions have been...

Commodity and energy prices have exhibited an unprecedented increase between October 2006 and July 2008, only to fall sharply during the last months of 2008. Many explanations have been offered to this phenomenon, including steadily increasing demand from China and India, large mandated...

A Bayes net has qualitative and quantitative aspects: The qualitative aspect is its graphical structure that corresponds to correlations among the variables in the Bayes net. The quantitative aspects are the net parameters. This paper develops a hybrid criterion for learning Bayes net structures...

Power and effect size analysis are important methods in the psychological sciences. It is well known that classical statistical tests are not robust with respect to power and type II error. However, relatively little attention has been paid in the psychological literature to the effect that...

This essay considers decision-theoretic foundations for robust Bayesian statistics. We modify the approach of Ramsey, de Finetti, Savage and Anscombe and Aumann in giving axioms for a theory of robust preferences. We establish that preferences which satisfy axioms for robust preferences can be...

Nitrate pollution from agriculture is an important environmental problem, caused bythe excessive use of inorganic fertilizers. The internalization of this externality, via a tax onmineral nitrogen, could lead to a second best solution, reducing nitrate emissions. Severalauthors suggest that a...

We analyze the current state and future requirements of an agricultural income stabilization mechanism in a transition country – namely, the crop insurance system in Kazakhstan. Three objectives will be pursued: First, factors influencing the development of the crop insurance market will be...

A mathematical programming model is developed and associated to a spatial pattern index (Ripley L function) to analyse the optimal reserve design and implementation for the Little Bustard conservation in Plaine de Niort. The model structure corresponds to three spatial levels, fields, farm and...