Urban digital twin governance: the efficiency-legitimacy trade-off

With the continuous aggregation of the global urban population and economic activities, the impact of digital technology on public governance has shifted from the tool level to the cognitive and logical levels. In this context, this study explores the evolution path and performance differences of urban digital twin (UDT) as a highly concentrated governance metaphor in different institutional environments. Objective: This article aims to explain the transnational differences between China and the EU in urban digital twin governance through the analytical perspective embedded in the system. The article examines how different institutional logics shape the allocation of the public sector's dynamic capabilities and explores the resulting trade-off between governance efficiency and legitimacy, particularly to provide strategic guidance for transition economies. Method: This study adopts the "Most Different Systems Design" (MDSD) method to compare and analyse the governance prototypes of China and the European Union. This study combines the institutional logic perspective (ILP) with the dynamic capabilities framework (DCF) to code policy texts and urban cases (for example, "city brain" and "citizen twins") to describe how system logic is transformed into the operational ability of "Sensing, Seizing, and Transforming". Results: This study found a structural "efficiency-legitimacy paradox": (1) The Chinese model, characterised by state-led vertical integration, minimises internal coordination costs and performs well in rapid closed-loop implementation ("output efficiency"), but faces challenges in accountability and diversity of innovative ecosystems. (2) The EU model, driven by rights protection and interoperability (for example, a multi-party information management system), ensures stronger "input legitimacy" and institutional resilience, but due to complex multi-stakeholder negotiations, it faces higher coordination friction and results in a slower diffusion rate. Conclusion: The governance performance of urban digital twin (UDT) depends not only on technical maturity, but also on institutional logic and the adaptability of organisational structure. The study shows that transition economies should avoid simply copying extreme models. On the contrary, they should build a hybrid governance architecture, dynamic balance between development pressure and rights constraints, and maintain a dynamic equilibrium between efficiency and legitimacy through hierarchical governance and interoperability mechanisms