Institute of Economics University of Copenhagen Innovation and Grow from

The recurrent issues of “non-robustness” and “scale e¤ects” are discussed within a uni…ed framework for the presentation of di¤erent generations of innovationbased growth models. With a certain proviso robust innovation-based growth models tend to end up with the long-run per capita growth rate pinned down by population growth. That is, the long-run prospect seems to be semi-endogenous growth. This is so also when essential non-renewable resources are taken into account. Semi-endogenous growth need not imply policy-invariant growth. Nonrenewable resources may imply instability problems of an unfamiliar kind. The projected slowdown of population growth is likely to decrease future per capita growth as well as the discount rate relevant for evaluation of long-term environmental projects. Keywords: Endogenous growth; non-renewable resources; instability; limits to growth; discounting the distant future. JEL Classi…cation: O4, Q3. — — This paper is an extended version of a keynote lecture given at the “Sustainable Resource Use and Economic Dynamics” conference held in Ascona June 7-10, 2004. I would like to thank, but not implicate, Carl-Johan Dalgaard, Poul Schou and Holger Strulik as well as participants at the SURED conference, in particular Sjak Smulders, for helpful comments.