We propose a novel taxonomy for identifying circular patents, focusing on 75,667 patents filed by Italian firms and granted by the European Patent Office between 1997 and 2019. The methodology combines Cooperative Patent Classification and International Patent Classification codes with a keyword-search algorithm, which flags patents as circular if titles or abstracts contain three or more CE-related terms. The algorithm, refined using a sample of 1,000 patents, substantially broadens the scope of circular patents beyond the set of waste patents typically used as a proxy. We analyze the evolution of Italian circular patents, their sectoral, geographical, and technological distributions, and the network of keywords found in their titles and abstracts.

Keywords: Circular Economy, Circular Innovation, Patent classification systems, Keywords-search analysis, Italy