Patenting and inventive activity on synthetic fibre intermediates

The demand-pull theory of invention and innovation has drawn much of its support from the work of Jacob Schmookler on patent time series. In this work, Schmookler found no evidence that scientific discoveries or major inventions had provided the stimulus for important inventions. However, it is argued here that his method was not well designed to detect such effects.Any effect of a particular scientific or technological development is likely to occur in a rather narrow area of technology, so that detection of science-push and technology-push will be favoured by the examination of narrow areas of inventive activity. Manufacturing processes for groups of chemical products subject to similar demand-side factors provide convenient such areas.In this study time series of patents on processes for eight intermediates for synthetic fibres have been examined. They are not consistent with a simple demand-pull theory, but rather with the view that inventive activity is affected both by demand and by technological opportunity. Two of the intermediates have been examined in detail, and evidence has been presented that in one case a major invention arose from science-push and in the other one arose from technology-push.