KLETTE, Tor Jakob; JOHANSEN, Frode - In: Annales d'Economie et de Statistique (1998) 49-50, pp. 389-419
Considering the observed patterns of R&D investment, we argue that a model which allows for a positive feedback from already acquired knowledge to the productiveness of current research, fits the empirical evidence better than the standard model that treats knowledge accumulation symmetrically...