[Analysis of the relation of research and development and patents].

Although there exists a close causal relationship between R&D and patents the attempt to establish a real connection suffers from certain difficulties. By means of specific methods a correlation between patent applications and R&D expenditure could be achieved at the national economic level. A previously developed concordance between the International Patent Classification and the systematics of sectors of the economy opens the possibility for a more differentiated analysis of the relationship between R&D and patents.