Corporate taxation within multidimensional sustainability profiles of European Union Member States

This study develops a multidimensional classification of sustainability-related profiles across the 27 European Union Member States over 2013–2023 using a balanced panel of 297 country-year observations. The baseline feature space combines real GDP per capita, greenhouse gas emissions, primary solid biofuel use, primary energy consumption, and the effective average corporate tax rate, with corporate taxation treated as a fiscal-context variable within the multivariate classification. Ward hierarchical clustering and k-means are applied to standardized data, while alternative solutions from k = 2 to k = 6 are evaluated using WCSS, silhouette, Calinski-Harabasz, Davies-Bouldin, cluster-size diagnostics, and Ward-k-means correspondence. The selected six-cluster solution records a silhouette coefficient of 0.485765 and is further assessed through repeated initialization, subsampling, annual membership trajectories, and two robustness specifications. The results reveal substantial heterogeneity in the joint economic, environmental, energy, and fiscal configurations of EU Member States. Twenty-two countries retain unchanged cluster membership throughout the study period, whereas five countries account for seven year-to-year transitions. Corporate taxation contributes to differentiation among the identified profiles without displaying a uniform association with environmental or energy conditions. Excluding Germany leaves the membership structure of the remaining observations almost unchanged (ARI = 0.995), while replacing aggregate environmental and energy variables with per-capita, proportional, and intensity-based measures produces a materially different partition (ARI = 0.513). The study contributes to sustainability-clustering research by integrating fiscal context, temporal membership, stability assessment, and specification sensitivity within a unified analytical framework. The resulting classification provides a structured basis for comparative benchmarking and context-sensitive assessment of heterogeneous sustainability transitions across the European Union.