We contend that clusters of cases co-constitute statistical interactions among variables. Interactions among variables imply clusters of cases within which statistical effects differ. Regression coefficients may be productively viewed as sums across clusters of cases, and in this sense...

In this article, we characterize efficient portfolios, i.e. portfolios which are optimal for at least one rational agent, in a very general financial market model of foreign currencies with proportional transaction costs. In our setting, transaction costs may be random, time dependent, have...

Do Africans have a metaphysics that is unique to them? If they do, what differentiates it from Metaphysics of other continents? This is the task that this paper sets to investigate and evaluate. This paper, however, holds that denying the existence of African metaphysics based on its primal...

We sketch a subset of Professor F.Y. Wu's contributions in lattice statistical mechanics, solid state physics, graph theory, enumerative combinatorics and other domains of physics and mathematics. We will recall some of F.Y. Wu's most important and well-known classic results and we will also...

Many dynamic incentive problems have primal recursive formulations in which utility promises serve as state variables. We associate families of dual recursive problems with these by selectively dualizing constraints. We make transparent the connections between recursive primal and dual...

The geometry of the Hicks-Slutsky income and substitution effect is framed in terms of the consumers expenditure function and expenditure equation and thus can be studied with-out resorting to the indifference map of a direct utility function.