True Wealth of Nations: Valuing Resources Beyond GDP as a Framework for Sustainable and Inclusive Economic Policy in the European Union

Moving beyond Gross Domestic Product (GDP) as the sole measure of economic performance is increasingly critical for addressing the complex challenges of sustainable development. The Inclusive Wealth Index (IWI) offers a more comprehensive framework for assessing long-term sustainability by accounting for changes in produced, human, and natural capital. This paper contributes to this debate by examining the comparative dynamics of these three forms of capital in Greece in relation to European Union averages. Specifically, we employ a repeated-measures design and the mixed ANOVA method to analyse their interactions over time (1990–2020) and across regional contexts. The novelty is to cover the research gap on how the different capitals interact, with Greece serving as a critical case given its environmental vulnerabilities, economic challenges, and position within the European sustainability agenda. The empirical results demonstrate a consistent hierarchy (human > produced > natural), significant growth over time, and pronounced regional disparities, with Western and Northern Europe outperforming Eastern and Southern Europe in overall capital stocks. Moreover, human, produced, and natural capital differed significantly ( η p 2 = 0.967 ) , with the EU-27 dominated by human and produced capital, while Greece lagged substantially ( η p 2 = 0.71 ). A robust interaction effect indicated structural divergence ( η p 2 = 0.811 ). The pairwise comparisons confirmed these results with very large effect sizes (Cohen’s d = 2.3–11.2 in the 95% CI). These findings underscore the importance of moving beyond GDP and highlight the policy relevance of inclusive wealth accounting for ensuring resilience and intergenerational equity.