Abstract: Support-for-agriculture efficiency serves as a critical metric for assessing how effectively policy-based agricultural credit guarantee institutions leverage fiscal funds to guide financial resource allocation.Utilizing panel data from 29 provincial-level institutions from 2018 to 2023 and employing an undesirable-output super-efficiency three-stage SBM-ML-Tobit model,this study yields the following empirical findings:(1) The average support-for-agriculture efficiency score across institutions is 0.680,indicating overall inefficiency.Decomposition of the score reveals pure technical efficiency of 0.810 and scale efficiency of 0.850,suggesting substantial potential for improvement in both dimensions.A notable regional disparity,with an efficiency gap of 1.389,underscores structural imbalances in resource allocation.(2) Total factor productivity experienced an average annual growth of 16.7%,exhibiting a distinct "high-growth initial phase followed by a moderated growth trend" pattern.With technological progress and technological efficiency change indices at 1.083 and 1.078 respectively,the lack of strong synergistic drive indicates that efficiency gains are increasingly challenged by diminishing policy dividends and intensifying market competition.(3) Institutional efficiency is significantly influenced by factors spanning five dimensions:operational foundation,governance mechanisms,product design,and risk management.Specifically,institutional independence and guarantee fee rates exhibit positive effects,whereas over-reliance on government-guarantor partnerships and average loan size demonstrate significant negative impacts.Consequently,policymakers and institutions should focus on enhancing independent governance mechanisms,refining collaborative government-guarantor models,developing differentiated product and pricing systems,and implementing comprehensive risk management frameworks to sustainably elevate support-for-agriculture efficiency and strengthen the rural fiscal-financial ecosystem.

Key words: agricultural credit guarantee, support-for-agriculture efficiency, SBM model, Malmquist-Luenberger index, Tobit model