The purpose of this paper is to derive a Rao's efficient score statistic for testing for heteroscedasticity in an error components model with only individual effects. We assume that the individual effect exists and therefore do not test for it. In addition, we assume that the individual effects,...

The aim of this paper is to model a liberal profession, in this case physicians. We propose a model in which the physician acts in the same way as an agent who maximises his utility function subject to his budget constraint, while at the same time being able to affect his rate of remuneration....

In this paper, we develop a new numerical method to estimate a multivariate probit model. To this end, we derive a new decomposition of normal multivariate integrals that has two appealing properties. First, the decomposition may be written as the sum of normal multivariate integrals, in which...