We introduce a notion of median uncorrelation that is a natural extension of mean (linear) uncorrelation. A scalar random variable Y is median uncorrelated with a kdimensional random vector X if and only if the slope from an LAD regression of Y on X is zero. Using this simple definition, we...

We introduce a notion of median uncorrelation that is a natural extension of mean (linear) uncorrelation. A scalar random variable Y is median uncorrelated with a kdimensional random vector X if and only if the slope from an LAD regression of Y on X is zero. Using this simple definition, we...

In a parametric model the maximum likelihood estimator of a parameter of interest &psgr; may be viewed as the solution to the equation l′-sub-p(&psgr;) &equals; 0, where l-sub-p denotes the profile <?Pub Caret>loglikelihood function. It is well known that the estimating function l′-sub-p(&psgr;) is not unbiased and that this...</?pub>