Assessing Patents based on Their Structural Significance in Patent Citation Network

This study proposes a patent assessment method based on a patent's structural role within a patent citation network. The proposed method includes two major steps: (1) assigning a weight to each citation of the patent citation network according to its traversal count within the network, and (2) obtaining a pivotalness value for each patent by summing the weights of its citations. A patent's pivotalness value is, therefore, the patent's traversal count within the network. If a citation may be deemed as a flow of knowledge or a step of technology evolution from the cited to the citing, the pivotalness value reflects a patent's significance in knowledge dissemination or technology evolution within the field. To observe this measure, this study selects for empirical analysis patents in the field of carbon dioxide capture, storage, recovery, delivery, and regeneration and collects a total of 34,083 US utility patents issued between 1976/1/1 and 2017/3/31 by the United States Patent and Trademark Office database.