In this paper we propose a unifying approach to study optimal growth models with bounded or unbounded returns. We prove existence of optimal solutions. We prove also, without using contraction method, that the value function is the unique solution to the Bellman equation in some classes of...

This paper analyzes optimal paths in a one-sector growth model when the technology is not convex. In such a case, we prove that optimal paths converge to the upper steady state iff the initial wealth is above a critical level. Then we first show that thanks to debt and/or R&D the poverty trap...

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...

In this paper we first prove an equilibrium existe theorem for finite dimensional economies with unbounded below consumption sets. We only assume that the individually rational utility set is compact and use the demand approach instead of the standard Negishi's approach. We next compare the...

This paper describes the multisectoral macroeconomic model of a small developing economy in transition, in order to highlight linkages between agriculture and the rest of the economy, and consequences of external opening up. Agriculture is a supply sector, sticky in the short range with market...