Multidimensional efficiency and institutional scale heterogeneity in protected areas: Evidence from Italy

Protected areas play a central role in territorial governance and the provision of environmental public goods, yet their performance is typically evaluated through effectiveness-based frameworks rather than through efficiency analysis. This study provides a multidimensional assessment of 27 Italian National Parks, conceptualized as multi-mission public organizations operating within complex territorial and institutional contexts. Four mission-specific domains - ecological performance, tourism valorization, managerial administration, and governance capacity - are evaluated using Data Envelopment Analysis within a non-radial framework that captures asymmetric inefficiencies across functions. The analysis explicitly examines the role of institutional scale, distinguishing between pure technical inefficiency and structural scale effects. Results reveal differentiated performance regimes: ecological outcomes are largely anchored in territorial endowment, whereas tourism and managerial domains exhibit both slack-driven and scale-related inefficiencies. Governance performance appears strongly conditioned by the configuration of institutional scales. These findings highlight the importance of scale alignment and mission-specific benchmarking for improving the design and coordination of protected-area governance systems.