Circular Economy Research Between Concept and Practice: A Bibliometric Audit and Exploratory Practice-to-Talk Framework (1996–2025)

Circular economy (CE) research has expanded rapidly, but its thematic communities differ in how strongly abstracts emphasise explicit CE framing relative to material-operational actions. We audit 20,066 publications (filtered from 25,823 English-language DOI-bearing records retrieved from OpenAlex, 1996–2025), organised into five thematic mega-areas using Sentence-BERT embeddings and hierarchical agglomerative clustering. We introduce the practice-to-talk ratio, a lexical indicator comparing references to material-operational actions (recycling, remanufacturing, reuse, and life-cycle assessment) with explicit invocation of CE terminology. The ratio varies by approximately an order of magnitude across mega-areas, from 2.07 in Materials & Technical Recycling to 0.22 in Business, Policy & Governance. This difference describes thematic orientation in abstract language; it does not measure research quality, implementation effectiveness, societal impact, or the value of conceptual, educational, governance, and behavioural contributions. Geographic attribution ( $$n=16{,}812$$ , 83.8%) shows small differences in Global North/South composition across mega-areas (article-level Cramér’s $$V=0.066$$ ), but the geographic ordering is not monotonic with the practice-to-talk ranking. The thematic ordering is also observed in an Open Access full-text sensitivity sample of 205 papers and in a separately constructed structured cross-check. We interpret the ratio as a descriptive indicator of textual orientation; any evaluative application of the associated four-tier framework would require independent validation against expert assessment and non-textual outcomes.