Smart Cities, Policy Interactions, and Urban Land Use Efficiency: Evidence from China

With the acceleration of digitalization, smart cities have emerged as a key institutional practice reshaping urban governance and spatial development. However, the impact of smart cities on land use efficiency and the conditions under which these effects are shaped by interactions among different policy tools remain insufficiently understood. This study adopts a policy mix perspective, situating smart city pilots within an institutional environment shaped by regulatory, incentive-based, and enabling policy tools, and systematically examines their impact on land use efficiency and underlying mechanisms. Based on data of 285 Chinese prefecture-level cities over 2000–2021, the study treats smart city pilot as a quasi-natural experiment and applies a staggered difference-in-differences (DID) design, supplemented by moderation and triple-difference models. The results indicate that the smart city pilot significantly enhances land use efficiency overall, although the effects vary across regions and topographical conditions. Further analysis reveals that policy tools with different functional attributes exert differential moderating effects: regulatory policy tools, represented by environmental regulation intensity, negatively moderate the land use efficiency gains of smart cities, while incentive-based tools, such as science and technology fiscal incentives, positively amplify these effects. Additionally, cities implementing both smart city pilots and the “Broadband China” Strategy pilot experience significantly greater improvements, highlighting the enabling policy tools in amplifying smart city performance. Overall, the impact of the smart city pilot on land use efficiency is not isolated but highly contingent on the surrounding policy mix. Interactions among policy tools systematically shape land use outcomes under digital urban governance, offering actionable insights for coordinated policy design.