Following Jones and Williams (2000), we assume that R&D is simultaneously subject to positive and to negative external effects (e.g., the non rival nature of technology conflicts with congestion externalities). This observation allows to conceive an economy where two R&D sectors evolve without...

Technological progress produces both positive and negative economy wide externalities. Although positive spillovers seem to prevail most of the times, there is evidence and logical arguments revealing that investment in R&D can exceed the corresponding socially optimal level. Taking on board the...

The traditional assumption concerning endogenous labor supply in models of economic growth is that utility increases with leisure, independently of the specific time allocation of the representative agent observed at a given moment. In this note, we explore the consequences, over dynamic...

The new Keynesian monetary policy model studies the response of the inflation – output gap trade-off to policy decisions taken by the Central Bank, concerning the nominal interest rate time trajectory. Under an optimal setup, this model displays a saddle-path stable equilibrium and, if the...

This paper develops a non-equilibrium dynamic model (NEDyM) with Keynesian features (it allows for a disequilibrium between output and demand and it considers a constant marginal propensity to consume), but where production is undertaken under plain neoclassical conditions (a constant returns to...

The standard two-sector growth model with physical and human capital characterizes a process of material accumulation involving simple dynamics; constant long run growth is observable when assuming conventional Cobb-Douglas production functions in both sectors. This framework is developed under...

The paper develops an AK endogenous growth model with an endogenously determined rate of intertemporal preference. Following some of the related literature, we assume that the degree of impatience that is revealed by the representative agent, regarding future consumption, depends on income. To...

Economic phenomena are interrelated. From a growth perspective, time analysis concerning the choices of present and future consumption and the choices between the allocation of scientific resources should be combined with a space analysis regarding the dissemination of economic activity through...

The aim of the paper is to develop a discrete time version of a one-sector optimal growth model with endogenous time preference. The intertemporal discount rate is determined by social factors (i.e., factors that are external to the individual agent), namely the economy wide levels of...

Two sector growth models, with physical goods and human capital produced under distinct technologies, generally consider a process of knowledge obsolescence / depreciation that is similar to the depreciation process of physical goods. As a consequence, the long term rate of per capita growth of...