The impact of the “Granularity” of ecological compensation policies on industrial structure upgrading in Yellow River Basin cities

The ecological protection and high-quality development of the Yellow River Basin constitute one of China's major national strategies. As a key institutional arrangement within the framework of ecological civilization, the ecological compensation policy plays a pivotal role in promoting regional green transformation and high-quality growth. However, existing research has primarily focused on the policy effects of ecological compensation, while systematic investigations into how the granularity of such policies influences industrial structure upgrading remain limited. To address this gap, this study systematically examines the impact of ecological compensation policy granularity on industrial structure upgrading, drawing on panel data from cities in the Yellow River Basin during 2011–2022 and the textual content of related policy documents. The results reveal that finer policy granularity significantly promotes industrial structure upgrading, with its effect becoming more pronounced as the level of granularity increases. Heterogeneity analysis indicates a spatial gradient in which the positive effect weakens from downstream to upstream cities, and it is relatively weaker in large cities compared with small and medium-sized ones. Mechanism analysis further shows that policy granularity facilitates industrial upgrading by fostering regional innovation and enhancing digital infrastructure development. Moreover, the moderating effect test suggests that regional industrial agglomeration amplifies the positive role of policy granularity. Finally, the productivity-enhancing effects of policy granularity are found to be strongest in the primary sector, followed by the secondary and tertiary sectors. These findings provide empirical evidence and policy insights for optimizing ecological compensation design and advancing high-quality development in the Yellow River Basin.