Science linkages focused on star scientists in the life and medical sciences: The case of Japan

We analyze the distributions of paper-paper and paper-patent citations and estimate the relationship between them, based on a sample of 4,763 published papers for which the corresponding authors were among the top 100 researchers in the life and medical sciences in Japan. We find that paper-paper citations peak at an average of 4 years after the publication of a paper, while the corresponding lag for paper-patent citations is 6 years. Although there is a time lag before papers can be put to practical use, this lag has shortened in recent years. Moreover, the quality of a paper is important for being cited by a patent, and a paper’s quality increases the number of paper-patent citations. In addition, we show that an inverse U-shaped relationship exists between the amount of research grant funding and research quality, and we can derive the efficient amount of research grant funding that maximizes research quality. We find that the relationship between research quality and the total number of papers written by the researcher(s) is U-shaped, and we derive the number of papers that minimizes research quality.