Fiscal Pressure of Ecological Compensation in Anhui Province Under the Yangtze River Delta’s Joint Ecological Protection: Regional Disparities, Causes, and Sharing Mechanisms

Within the trans-regional ecological governance framework of the Yangtze River Delta (YRD), Anhui Province acts as a critical ecological barrier. Yet, intra-provincial disparities in the fiscal pressure of ecological compensation remain underexplored. Drawing on panel data from 16 prefecture-level cities in Anhui (2018–2024), we develop a hierarchy–region dual-dimensional framework. This framework measures fiscal pressure by integrating cost–benefit and opportunity–cost methods. A two-way fixed-effects model exhibits a distinct spatial gradient: fiscal pressure decreases in the order of Southern (19.58%) > Northern (13.45%) > Central Anhui (5.24%). Mechanism tests support the “Triple Systemic Mismatch” as a coherent interpretive lens: fiscal pressure is positively associated with ecological contribution and negatively associated with fiscal capacity and industrial structure. Furthermore, regional integration policy significantly alleviates such fiscal pressure. Accordingly, this study puts forward a three-dimensional sharing mechanism that integrates government coordination, market empowerment, and social participation to support equitable cross-regional governance.