Long waves,inventions, and innovations

It is argued that aggregate R and D and patenting activity, while generally less volatile than short term economic activity, is more closely related to the latter in the longer term. Second, ‘fundamental’ or ‘basic’ inventions exhibit a clustering behaviour, although there appears to be no clear-cut relationship with the overall level of economic activity. Third, we find no support for Mensch's argument that lead times between invention and innovation contracted in the 1930s. Fourth, we find some evidence for a bunching of innovations in the 1930s, but this does not appear due to depression-induced acceleration. Fifth, in the particular case of plastics, where the 1930s clustering is particularly clear, the forces at work were primarily related to ‘science push’ and the particular requirements of the German economy.