We address in this paper the question of the existence of a Social Welfare Function that would be sustainable and would allow us to obtain solutions to optimal growth models. We define sustainability by two new axioms called Never-decisiveness of the present and Never-decisiveness of the future....

Properness of preferences are useful for proving existences of an equilibrium and of supporting prices in Banach Lattices. In this paper we characterize completely properness and uniform properness for separable concave functions defined in $L^{p}_{+}.$ We prove also that every separable concave...

This paper presents a discrete time version of the Romer 1986 model of endogenous growth. The purpose of this work is to propose detailed and simple proofs of existence of optimal solutions and of a competitive equilibrium. The framework implemented here reduces the complexity of the proofs...

Properness of preferences are useful for providing existences of an equilibrium and of supporting prices in Banach Lattices. In this paper we characterize completely properness and uniform properness for separable concave functions defined in L[subscript {plus}][superscript p]. We prove also...