TAMADA Schumpeter (Faculty Fellow, RIETI) /NAITO Yusuke/GEMBA Kiminori/KODAMA Fumio (Faculty Fellow, RIETI) /SUZUKI Jun/GOTO Akira (Faculty Fellow, RIETI)
We constructed an original database concerning science linkages based on text of Japanese Patent Gazette published since 1994. We discovered that Japanese inventers cite many academic papers in the texts of the patent applications in the Japanese Patent System. Based on this finding, we constructed science citation index by data mining the texts of Japanese patent system for the first time. First, more than 880,000 patent data classified into about 600 categories. Then, we extracted non-patent references from all the granted patents and counted the number of them. This number shows the strength of the linkage between science and technology and therefore is called "science linkage index." The science linkage indexes among different patent classifications differ significantly from each other. The technologies related to bio -technology were by far the closest to science. It suggests that the process of creating new technology differs from technology to technology.