The Effects of Smoothing of the Renewal Fees on Patent Option Value(in Japanese)

This paper aims to construct a patent option model suitable for the Japanese patent system, and then to explore empirically the economic effects caused by the significant revision of the Japanese patent maintenance fees in 1998. The revision of patent law in 1998 fundamentally changed the fee schedule so that payments peaked in ten to twelve year after patent registration, followed by a level off, which resulted in major fee reductions. This was a very bold change in the patent fee structure compared to historical structures of patent fee maintenance in Japan and other major countries. The leveling-off of patent maintenance fees was aimed to reduce cost burden on patent owners and to give incentives to their R&D activities. In addition, it served to contain the special patent account's rising surplus. The simulation results based on the patent option model show that the introduction of the leveling-off maintenance fees enables the patent to hold the patent term longer, while minimizing the influence on the patent option value. However, it is confirmed to have a relatively substantial effect on reducing patent fee revenues.