Intellectual capital reporting in sustainability reports

Purpose The purpose of this paper is to analyse voluntary disclosures of intellectual capital (IC) items in the sustainability reports of Portuguese companies. The paper aims to highlight the level, pattern and determinants of IC disclosures in those sustainability reports; and the potential for sustainability reports to be a medium for IC disclosures. Design/methodology/approach An index of voluntary disclosure of intangibles is constructed and deployed to analyse IC disclosures in the sustainability reports for 2006 of Portuguese firms, published on the web site of the Portugal's Business Council for Sustainability Development. Four hypotheses are tested about associations between that disclosure index and firm‐specific variables. Findings Disclosure of information about IC is more likely in sustainability reports of firms that have a higher level of application of the Global Reporting Initiative framework, and are listed companies. Research limitations/implications This study is cross‐sectional. Subjective judgment is involved in constructing the disclosure index. Practical implications The observed level and pattern of disclosure of IC information suggests that the preparation of a sustainability report is an opportune starting point for the development of IC reporting. Originality/value The study highlights the determinants of IC disclosures in sustainability reports; the high incidence of such disclosures; and points to the enhancement of legitimacy and reputation as potential incentives for firms to engage in such practice.