Linkage between patents and papers: An interim EPO/US comparison

A unification of more than one million non-patent references (NPR's) on the front pages of U.S. and EPO patents has been carried out, with a subsequent match to the Science Citation Index (SCI), in order to investigate the citation linkage between patented technology and the scientific research literature. The U.S. system shows an extremely rapid increase in linkage, with citations from U.S. patents to U.S. authored papers increasing more than three-fold over the last decade. The EPO system does not show any increase; the occurrence of non-patent references appears to be relatively constant in the EPO system over the last decade. In both systems the cited papers are in relatively basic journals, especially in biomedicine. In the U.S. system approximately 75 percent of the cited papers originate in public science institutions, showing large dependence of patented industrial technology on public science. We expect to find similar result in the EPO system.