Mediating effect test.

This study explores the influencing factors and driving pathways of rural public cultural service supply effectiveness in Southwest China, addressing the core question, “How does supply effectiveness emerge?” Based on Parsons’ AGIL structural-functional theory, this paper constructs a systematic theoretical framework encompassing “Resource Allocation (A)—Policy Support (I)—Value Shaping (L)—Service Production (G)—Service Effectiveness.” Structural equation modeling was applied to empirically analyze 610 valid questionnaires collected from multiple rural areas in Sichuan Province. Findings reveal that resource allocation serves as the foundational driving force of the system, enhancing service effectiveness primarily through the mediating effects of policy support and service production. Policy support exerts a significant direct effect on value shaping and service effectiveness, but its direct impact on service production is insignificant. Although value shaping does not directly drive service production, it plays a crucial indirect role by enhancing service effectiveness. As the output component of the system, service production directly influences service effectiveness. This study reveals the structured, networked mechanisms that enhance the effectiveness of rural public cultural service supply, providing theoretical and empirical foundations for optimizing supply structures and implementing targeted interventions.