Abstract
This paper quantitatively shows that RD expenditure is a major source to increase patent applications in the Japanese industry. The number of researchers is not a major source to increase patent applications because the number of patent applications per researcher increases when the number of paten applications increases rapidly. The strong positive correlation between RD expenditure and patent applications has been statistically proved at the industry level for the first time. Based on this statistical analysis, time-lag and RD cost to create a patent application are measured by industry. The chemical product industry including the pharmaceutical industry needs a longer time and bears higher RD cost to create a patent application than other industries. The paper also shows that the productivity of RD expenditure to create patent applications increased over time in Japan due to the change of managerial factors such as slim management.
