Scale Effects in Idea-Based Growth Models: a Critical Survey

This paper gives an overview on the topic of scale effects in idea-based growth models in a closed economy. I deal with weak and strong scale effects and with the crucial distinctive features of the three strata of idea-based models. I comment third-generation models emphasizing their fragile framework because of treating the potential R&D spillover space in a too simplified way. Finally I argue according to this and other shortcomings of third-generation models that a definite mapping of the relationship between population size and economic growth requires further research: strong scale effect is still on agenda!