The principal aim of this paper is to demonstrate how the coordinate-free methods of linear statistical models may be adapted to the analysis of econometric models, and to explain why such methods are useful for teaching purposes. The application of coordinate-free methods to linear statistical models cast in Euclidean space was first introduced by Kruskal(1961). Later, the methodology was exte...

Abstract Inspired by the papers [2, 10] we will study, on 2-divisible groups that need not be abelian, alienation problem between Drygas’ and exponential Cauchy functional equations, which is expressed equation f ( x + y ) g...

Let $$(S,+)$$ be an abelian semigroup, let $$(H,+)$$ a uniquely 2-divisible, group and $$\sigma ,\tau $$ two endomorphisms of S. In this paper, we find the solutions $$f:S\rightarrow H$$ following Drygas type functional Eq. 1 $$\begin{aligned} f(x+\sigma (y))+f(x+\tau (y))=2f(x)+f(\sigma (y))+f(\tau (y)), \quad x,y\in S, \end{aligned}$$ in terms additive bi-additive maps. Further, solve partly ...