Effect of Collaboration on Patent Maintenance Length

Although the number of collaborative patents is small and the rate of patent collaboration is low, the average citation rate of collaborative patents is substantially high. Among the collaborative patents with various validity terms, the collaborative patents with 12-year validity terms have the highest average number of citations. The explanation for this has yet to be determined. The average number of citations of collaborative patents with 4- and 8-year validity terms was similar; however, their collaboration rates differed significantly. A comparison of the two technological fields revealed fewer collaborative patents and a lower collaboration rate across the four validity terms in the ME technological field than in the EE technological field; the average number of citations across the four validity terms was higher in the ME technological field than in the EE technological field. The results indicate that collaborative patents have a significant effect across the four validity terms.