Circular intellectual capital and disclosure readiness in European port ecosystems

Purpose This study examines how public sustainability disclosures in European port ecosystems reveal the maturity of governance and measurement structures supporting circular intellectual capital (CIC) and credible circular transition claims. Rather than assuming carbon-insetting as an empirically established practice, this study uses insetting-like value chain decarbonisation initiatives as an analytical benchmark. Double materiality is interpreted as a governance maturity benchmark, avoided emissions (Scope 4) as a measurement maturity benchmark and knowledge decoupling as a lens for assessing the credibility of disclosure. Design/methodology/approach This study applies qualitative content analysis to sustainability reports, integrated reports and selected website disclosures from leading European ports. Automated analysis using Leximancer is combined with manual coding to examine how decarbonisation initiatives are disclosed and whether they are supported by observable governance, boundary-setting, measurement and verification cues. Findings The results reveal that European ports widely disclose value chain decarbonisation initiatives connected to human, structural and relational capital; however, the disclosure of advanced accountability elements remains uneven. Double materiality is only partially integrated, while avoided emissions (Scope 4) are rarely supported by explicit methodologies. This suggests that port disclosures are more developed at the level of operational decarbonisation narratives than at the level of governance and measurement architectures required for credible accountability. Originality/value This study contributes to intellectual capital and sustainability disclosure research by repositioning CIC as a capability whose credibility depends on the governance and measurement structures through which it becomes publicly visible. It also advances a diagnostic approach to port disclosures by using double materiality and avoided emissions as maturity benchmarks and knowledge decoupling as a lens for distinguishing aspirational claims from more bounded, structured and credible forms of disclosure.