农机作业服务对农业生态效率的影响：本地效应与空间溢出

为探究农机作业服务对农业生态效率的影响，基于中国2004—2019年省级面板数据，采用规模报酬可变型非期望超效率SBM模型对中国农业生态效率进行测算，并运用双向固定效应模型和双固定空间杜宾模型分析了农机作业服务对农业生态效率的本地效应及空间溢出影响。结果表明：中国农业生态效率近年来呈现波动式下降趋势，东部地区生态水平较高，中、西部地区相对滞后；农机作业服务与农业生态效率间存在正向相关关系，农机作业服务对农业生态效率的直接效应、间接效应和总效应分别为0.006、0.017和0.024,间接效应约占总效应的75%,表明农机作业服务对农业生态效率影响将会是系统性的，这对推动中国农业高质量发展具有重要作用。

Impact of agricultural machinery services on agro-ecological efficiency: Local effects and spatial spillovers

In order to explore the impact of agricultural machinery services on agro-ecological efficiency. based on China''s provincial panel data from 2004 to 2019, this study used the variable return-to-scale non-expected super-efficiency SBM model to measure China''s agricultural ecological efficiency. The two-way fixed-effect model and double-fixed space Durbin model were also adopted to analyze how machinery services influence agro-ecological efficiency in local and other regions. The result show that: China''s agricultural ecological efficiency has shown a fluctuating downward trend in recent years, the ecological level in the eastern region is relatively high, and the central and western regions are relatively lagging; There is a positive correlation between agricultural machinery services and agricultural ecological efficiency, and agricultural machinery operation services have a positive impact on agricultural ecological efficiency. The direct effect, indirect effect and total effect are 0. 006, 0. 017 and 0. 024, respectively. The indirect effect accounts for about 75% of the total effect, indicating that the impact of productive services on agro-ecological efficiency will be systematic and the development of agricultural machinery services will play the key role in promoting high-quality agriculture in China.