Adaptive Smart-City Governance Under European Digital Regulation: A Comparative Systems Analysis of Madrid and Barcelona

Cities increasingly operate as complex adaptive systems in which institutional capacity, civic participation, environmental pressures, digital infrastructures, and regulation interact across multiple levels. Yet less is known about how these dimensions combine within alternative metropolitan governance configurations and how common European digital regulation becomes embedded in them. This study asks how the five analytical domains combine into distinct metropolitan smart-city governance configurations under a shared regulatory environment and how path-dependent institutional trajectories shape those combinations. A structured qualitative comparative case design was applied to 34 institutional documents from Madrid, Barcelona, Spain, and the European Union. Documents were coded through a theory-informed framework and examined through within-case analysis, pattern matching, documentary triangulation, and cross-case comparison. The findings identify two overlapping configurations: Madrid shows stronger digital-administrative integration, transversal coordination, and outward-facing strategic development, whereas Barcelona displays greater municipal–metropolitan articulation, policy-specific civic participation, and socio-ecological embedding. In both cases, the GDPR and EU AI Act operate as institutional boundary conditions whose local incorporation depends on existing governance trajectories. The study shows that similar regulatory and technological pressures can be absorbed through different governance configurations and proposes ecosystemic stewardship as an interpretive bridge between adaptive metropolitan governance and strategic place management.