中国粮食产量变化的驱动效应及其空间分异研究

Driving effects of grain production change and its spatial differences in China

粮食安全是一个国家和地区经济和社会稳定发展的基础,而粮食产量则是衡量粮食安全的最为重要指标,研究粮食产量变化的驱动效应对于实现其持续稳定增长具有重要意义。综合考虑种植业结构、农林牧渔业结构、农业生产经济收益、农业劳动力等各因素对粮食产量的影响,从农业经济学的视角出发,构建了粮食产量分解的理论框架。基于这一框架,将粮食产量变化分解为种植经济的粮食安全效应、农业结构调整效应、农业劳动力农业经济收益效应、农业劳动力当量效应等4种。采用对数平均迪氏分解模型(LMDI)和粮食生产的空间转移系数,揭示了4种效应对1978—2014年中国粮食产量的时序变化以及2000—2013年全国31省(市、区)粮食产量的空间变化的影响程度。研究结果表明:无论从时间还是空间变化方面,农业劳动力农业经济收益效应都是驱动粮食增产的首要因素,种植经济的粮食安全效应则是抑制粮食增产的首要因素。在政府主导模式下,农业结构调整对粮食增产的负面影响较小,而在农户主导模式下,农业结构调整对粮食产量的负面影响明显增强,这一结果在粮食主产区表现尤为明显。1978—2014年,中国劳动力当量效应对粮食产量变化由正向驱动作用不断向负向抑制作用转变,且其对粮食增产的抑制作用不断增强,这一现象在粮食主产区表现也尤为突出。因此,为促进中国粮食产量持续增长,尤其需要发挥政府在粮食主产区农业结构调整中的主导作用,在确保农民生产粮食基本收益的基础上,加快延伸粮食生产产业链,进一步增加农民收入来源,促进劳动力资源在城乡之间的有效配置。

Food security is the basis of national and regional economic development and social stability, and total grain output is its key measuring index, therefore measuring the driving effect of total grain output change is of great importance to achieve its sustainable growth. Taking the four factors, cropping structure adjustment, agricultural structure adjustment, economic benefit of agricultural production and amount of agricultural labors, into synthetical consideration, a theoretical analytical structure has been constructed to analyze China＇ s grain production change from the perspective of agricultural economics. Based on this structure, grain production change can be decomposed of four driving effects which are food security effects of cropping economy, agricuhural structure adjustment effect, economic benefits effect of agricultural labors and changing effect of agricultural labor amounts. Using Logarithmic Mean Divisia Index model （LMDI） and spatial transfer index of grain production, we analyzed the four driving effects of China＇ s grain production change from 1978 to 2014 and its provincial differences from 2000 to 2013. The results showed that whether from temporal or spatial perspective, increasing of economic benefit effect of agricultural labors was the most important positive factor to grain production growth, and the key negative factor was food security effects of cropping economy in China. When it was dominated by the Chinese governments, agricultural structure adjustment only had small negative effects on grain production; however greater negative effects would occur while it was dominated by farming households, particularly in major grain production areas. From 1978 to 2014, changing effect of agricultural labor amounts to grain production turned from positive into negative, and its limiting strength to grain production growth became stronger with time, particularly in major grain production areas. In order to achieve sustainable growth of grain output, Chinese government should be dominated in agricultural structure adjustment especially in major grain production areas. On the basis of insuring basic benefits of grain producing, grain industry chain should be extended to further boost the revenue of peasants, and labors should be allocated effectively between urban and rural areas.