Efficiency of hidden knowledge spillovers between firms and universities in Japan: An empirical analysis based on patent data

This paper investigates the effect of knowledge spillovers from academia to industry by focusing on patents transferred from universities to enterprises. In many studies, joint patent applications are utilized to measure the economic effects of academia-industry alliance, since such patents are considered to be one of the most significant research outputs. However, in reality, most important scientific or technological results of joint research are considered to be transferred from universities to companies for a fee before related patent applications are filed. On the basis of quantitative analysis of patent data in Japan, it is shown that, at least for enterprises, knowledge flows of transferred patents play a more significant role than those concerning joint applications. Since both the patent allowance rate and the Patent Cooperation Treaty (PCT) application rate of transferred patents are larger than those of joint applications, it is suggested that, on average, higher marks are given for transferred patents both by examiners and enterprises. In addition, we discuss how the detailed differences in open innovation strategies of each company can be depicted by utilizing the shares of transferred patents.