The Gini index and the Gini mean difference of a univariate distribution are extended to measure the disparity of a general d-variate distribution. We propose and investigate two approaches, one based on the distance of the distribution from itself, the other on the volume of a convex set in (d...

We develop a product market theory that explains why firms invest in general training of their workers. We consider a model where firms first decide whether to invest in general human capital, then make wage offers for each others' trained employees and finally engage in imperfect product market...