The paper presents a complete characterization of the local dynamics for optimal control problems of 4-dimensional systems of ordinary differential equations, by using geometrical methods. We prove that the particular structure of the Jacobian implies that the 8 th order characteristic...

We develop a multi-sector model of R&D-driven endogenous growth that merges the expanding-variety with the quality-ladders mechanism. The mechanism of expanding variety provides the flow of new firms (new product lines), whilst the mechanism of quality ladders provides the accumulation of...

In a Yaari-Blanchard overlapping generations endowment economy, and drawing on the equivalence between Radner (R) and Arrow-Debreu (AD) equi- libria, we prove that equilibrium AD prices have an explicit representation as a double integral equation. This allows for an analytic characterization of...

We present a continuous time overlapping generations model for an endowment Arrow-Debreu economy with an age-structured population. For an economy with a balanced growth path, we prove that Arrow-Debreu equilibrium prices exist, and their dynamic properties are age-dependent. Our model allows...

The major distinctive feature of cultural goods is that consumers must learn how to consume them, implying that preferences should be modelled as intertemporally dependent. The canonical model in the literature uses a habit formation analogy. In this paper, we discuss in detail, though in the...

This work focuses on assessing the potential for generation of biomass residues from agroforestry sources in a region of Portugal (Alto Alentejo), within the scope of energy valorization of the biomass by means of combustion technologies. The model uses a GIS-based method to estimate the...