A methodology to position nations' efforts in a technology domain with a patent network analysis: case of the electric vehicle domain

When a nation is making strategies in a technology domain, it makes sense to know where the nation is currently in the domain and to know where other nations are as well. This paper presents a method to position nations' efforts in a technology domain. The method builds a network of International Patent Classifications (IPCs) based on their co-occurrence in patent applications and applies an index called the Revealed Patent Application Advantage (RPAA), which reflects where nations' efforts have been spent in a technology domain denoted as the IPC network. We applied the proposed method to position the efforts that have been spent in the electric vehicle (EV) technology domain by mainland China, Germany, Japan, and the United States.