劳动力价格上升、要素替代与要素投入结构变化——来自中国大豆生产的证据

Rising labor prices,input substitution,and input structure changes:Evidence from soybean production in China

为了探析劳动力价格上升背景下非三大主粮粮食作物要素投入结构的变化情况,文章采用1991—2018年中国大豆生产要素价格和要素投入的相关数据,基于超越对数成本函数,运用似不相关回归估计我国大豆生产成本份额方程,并测算要素需求弹性和替代关系。研究结果表明:在我国大豆生产中,劳动力和化肥需求缺乏弹性,机械需求富有弹性但有减弱趋势;机械、化肥和劳动力之间存在两两替代关系,其中机械与劳动替代关系最强,化肥与劳动替代关系最弱;机械对劳动的替代关系有下降趋势,化肥对劳动的替代关系有上升趋势。因此,建议通过以下方式优化我国大豆生产要素投入结构:1)通过农机具购置补贴等政策进一步促进大豆生产机械技术推广,降低生产成本;2)用地与养地相结合,统筹作物轮作和种植业结构调整,加强技术攻关,加大大豆生产机械技术研发和推广;3)兼顾化肥利用效率和生态收益,优化肥料施用种类,采用生物和物理方式来代替部分化学肥料,借助机械和“外包”服务优化施肥方式。

In order to analyze input structure changes of non-three staple grains under the background of rising labor prices,based on the data of input prices and quantities of soybean production from 1991 to 2018 and applying the trans-logarithmic cost function and the seemingly unrelated regression,this paper estimated the production cost share equation of China’s soybean and calculated the demand elasticity and substitution relationship of inputs.Results show that:in China’s soybean production,the demand elasticities for labor and fertilizer are inelastic,and the demand elasticity for machinery is flexible with a weakening trend.There is a pair-wise substitution relationship among machinery,fertilizer,and labor,of which the substitution relationship between machinery and labor is the strongest,and the substitution relationship between fertilizer and labor is the weakest.In addition,the substitution relationship between machinery and labor has a downward trend,and the substitution relationship between chemical fertilizer and labor has an upward trend.Therefore,this paper suggests to optimize the input structure of soybean production in China through the following methods:1)further promoting the adoption of soybean production machinery technology through agricultural machinery purchase subsidies to reduce soybean production costs;2)combining land use and land maintenance together,coordinating crop rotation and crop structure adjustment,and strengthening research and extension service of soybean production machinery technology;and 3)taking into account the utilization efficiency of chemical fertilizer and ecological benefits,optimizing the types of fertilizers,applying biological and physical methods to replace some chemical fertilizers,and optimizing the fertilization ways with machinery and outsourcing services.