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...

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...

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...

Endogenous growth models are generally designed to address long term trends of growth. They explain how the economy converges to or diverges from a balanced growth path and they characterize aggregate behaviour given the optimization problem faced by a representative agent that maximizes...

This note develops a simple macro model where the pattern of wealth accumulation is determined by a credit multiplier and by the way households react to short run fluctuations. In this setup, long term wealth dynamics are eventually characterized by the presence of endogenous cycles.