This paper proposes a theory for the gradual evolution of knowl-edge diffusion and growth over the very long run. A feedback mechanismbetween capital accumulation and the ease of knowledge diffusion explains along epoch of (quasi-) stasis and an epoch of high growth linked by a grad-ual economic...

Previous research on optimal R&D subsidies has focussed on the long run.This paper characterizes the optimal time path of R&D subsidization in a semi-endogenous growth model, by exploiting a recently developed numerical method.Starting from the steady state under current R&D subsidization in the...