Entry and growth in a perfectly competitive vintage model

A perfectly competitive vintage-knowledge model of Schumpeterian growth is introduced to study the relation between growth, technology-lifetime, entry, and productivity-dispersion. The incentive to innovate is generated by the productivity-dispersion (latent in traditional vintage models) between new and old plants, rather than by monopoly rents. The model has a unique steady-state REE with endogenous growth. The endogenous extent of entry constitutes a buffer, dampening the effect of research-efficiency and completely neutralizing the effect of population size or population growth rates on per-capita income levels and growth rates. Variations of research-efficiency lead to a negative relation between growth and vintage-lifetime and a non-monotonic relation between growth and productivity-dispersion.