How Can a Technology Manager Find a Technological Generality in Its Early Stage: Revisiting Backward-Forward Citation Analysis

This paper is a modest attempt to revisit linkages between backward and forward citations posed by Trajtenberg, Henderson and Jaffe. In their literature known as the leading study, they suggest that more original research, as well as research that draws from far removed technological areas, lead to innovations of wider technological applicability. It is still unclear, however, whether backward citations captures patent importance. Although it is becoming clear that forward citations are a good predictor of important inventions, it is imperative to take quite a wide time window in order to get significant coverage of forward citations, which makes it difficult to count all of the forward citations in early stage. This problem could be more remarkable in such countries as Japan with examination-on-demand system. On the other hand, patent examination has been accelerated after the Accelerated Examination System (AES) was implemented in Japan. This means that there is a high possibility among applications examined under AES that backward citations cited by such applications are visible in public in early stage (i.e. at the time of laying-open publication of the applications). This trend can be an important issue for practitioners who use patent information as a tool for innovation research.