Patents System and Negative Externalities of R&D - 특허제도와 R&D 외부효과 -

“Stepping on toes” effects are prevalent due to negative duplication externalities. These problems may be avoided by shortening patent duration. Short duration of patent protection increases legal knowledge dissemination, decreases the use of congested input resources(labor or money) for gaining the same patent rights and reduces duplication of R&D efforts. In addition, it has another advantage of reducing the inefficiency from monopoly pricing. Empirical tests show that European countries like Germany and France have less (negative) duplicative externalities than other countries. This may be due to two-tire patent system consisting of petty patents for three years and patent renewal system. In contrast to these countries, the US has longer renewal interval as 4 years, so our empirical result reveals large negative duplication externalities in the US. Finally, it is worth to note that narrowing the patent breadth may have the effect of promoting creativity, but the weakness of causing research duplication to occur.