Abstract We propose a novel taxonomy for identifying circular patents. Our methodology identifies patents as circular if they satisfy at least one of the following conditions: (1) they pertain to waste management technologies, (2) their titles and abstracts combined contain at least three keywords related to the circular economy paradigm. The algorithm, refined using a sample of manually validated patents, substantially broadens the scope of circular patents beyond the set of waste patents typically used as a proxy. Drawing on 75,667 patents filed by Italian firms at the European Patent Office between 1997 and 2019, we examine the evolution of circular patents, their geographic and technological distribution, the main characteristics of their applicants, and the network of keywords found in their titles and abstracts.
Lanza et al. (Tue,) studied this question.