This paper provides an empirical analysis of the relationship between R&D intensity, rate of innovation and the growth rate of output in four manufacturing sectors from 17 OECD countries. The findings suggest that the knowledge stock is the main determinant of innovation in all four manufacturing sectors and that R&D intensity increases innovation in the chemicals and the electrical and electronics sector. In addition, the rate of innovation has a positive effect on the growth rate of output in all sectors except for the drugs and medical sector. These results lend strong support for the non-scale endogenous growth models. *I am grateful to Adam Jaffe for his invaluable suggestions and comments.