粮食生产下滑真的源于农地产权边际效应递减吗?——来自1978～2010年中国省级数据的证据

Does Decline of Grain Production Stem from the Diminishing Marginal Effect of Land Tenure:Base on Chinese Provincial Data from 1978 to 2010

以往研究普遍将1984年之后我国粮食生产下滑归因于农地产权的边际效应递减,这一方面忽视了农地产权作用发挥依靠的是赋予农户决策自由这一事实;另一方面也使得农地产权持续强化与粮食生产下滑的悖论一直未被阐明。为此,本文利用1978～2010年省级面板数据,分析了农地产权和经营效益在不同历史阶段对粮食生产的影响。结果表明,1978～1984年,由于国家粮食生产管制和城乡人员的流动约束,粮食经营扩大与国家收购价格的增长具有逻辑一致性,农地产权的强化也就有助于激励粮食生产。1985年之后,由于农产品价格市场化和城乡户籍制度及劳动力流动的放开,农地产权的强化使得农户具有更多的自由按照比较效益进行种植结构调整。加之农户在产权稳定性不断提高的情况下更多地进行非农转移,造成粮食生产下滑。由此可见,粮食生产下滑并非来自农地产权边际效应递减,而是因为农户决策自由的扩展,由此造成他们在种植业结构调整和家庭要素部门配置中更有能力考虑比较收益问题。最后,文章从农业经营制度实施的情景约束,以及'交易装置”构建等方面,探讨了我国农业政策设计和实施的基本方向。

In the past, the decline of grain production in China after 1984 was attributed to the diminishing marginal effect of land tenure, which not only ignored the fact that the working of land tenure is dependent on the freedom given to farmers to make decisions, but also made the contradiction between the continuous strengthening of land tenure and the decline of grain production. The paper employs provincial panel data from 1978 to 2010 to analyze the impacts of land tenure and management benefit on grain production in different historical period. The research result indicates that, from 1978 to 1984, due to the regulation of national grain production and the restriction of urban-rural labor migration, the expansion of grain management and the increase of state purchasing price are logically consistent. After 1985,due to the liberalization of agricultural product price, the release of urban-rural registration system and the flow of labor force, the perfection of land tenure attribute farmers more freedom to adjust the planting structure according to the comparative income, which with the stability of land tenure encouraging farmers’ migration leads to decline of grain production. Thus, the decline of grain production is not from the diminishing marginal effect of land tenure, but because of expanding farmers’ action freedom which results in farmers have capability to consider comparative income during their adjustment of planting structure and the department allocation of family factors. At last, the paper discusses the basic direction of agricultural policy design and implementation in China from the aspects of the situation constraints of agricultural system implementation and the construction of "transaction device"