规模经营补贴与粮食量质安全——来自规模经营农户的证据

Subsidy to Large-scale Farming and Food Quantity-Quality Security: Evidence from Large-scale Farmers

中国作为人口大国既要追求粮食总产量的稳定上升和农民增收,又要降低化肥和农药的使用以促进粮食生产的高质量发展。为了提升粮食安全和促进农户增收,中国2015年试点粮食规模经营补贴并逐步推广,但现有文献对这一政策的效果尚未做出全面评估。基于2013—2017年全国农村固定观察点调查数据,本文利用三重差分法研究发现该政策具有双面效果:它提高了粮食亩产量、劳动生产率、种粮收入和种粮利润,但却导致规模经营户更多地使用化肥和农药,这是因为补贴缓解了农户的信贷约束并提高了他们的要素投入积极性。基于全国地表水水质数据和空气成分数据的进一步研究发现,补贴政策显著提高了粮食作物生长季节的水源中氨氮以及空气中的二氧化氮含量,这为规模经营补贴导致规模经营户多用化肥提供了有力证据。本文揭示了规模经营补贴政策的增产增收正面效果以及多用化肥和农药的负面效果,为优化农业规模经营补贴政策促进粮食安全的数量和质量“双提升”提供了重要启示。

China needs to feed more than 1.4 billion population without importing too much grain from other countries.It also needs to provide more types of food with increasingly high quality to such a huge population.This has put forward high pressure and challenges on China’s grain planting and agricultural policy-making.However,China is the world’s largest user of chemical fertilizers and pesticides.Excessive use of chemical fertilizers and pesticides has led to soil acidification and compaction,as well as water and air pollution.Moreover,excessive use of pesticide can potentially endanger food safety in China.In this context,China’s agricultural policy should not only pursue both increase of total grain output and improvement of food security,but also reduce agricultural pollution to improve the quality and sustainability of grain planting.In order to improve the level of food security and sustainable development,following the policy framework of WTO,China launched a pilot project to subsidize large-scale farming(LSF)in 2015,which was promoted nationwide ever since.This policy focuses on providing support to new agricultural business entities such as large-scale grain growers,family farms,farmers’cooperatives and agricultural socialized service organizations to engage in scale management of grains.In 2017,the central government channeled CNY 23 billion to the project of LSF.This policy has been in place in China for several years,and the government expenditure on this project is large,however,the effects are yet fully understood or carefully evaluated by present economic literature.This paper is among the first which fills in this gap by providing a comprehensive evaluation of this policy.Based on nationally representative rural household data collected by the Ministry of Agriculture and Rural Affairs of China from 2013 to 2017,this paper finds that the subsidy policy for LSF has two-sided effects through the difference-in-difference-in-differences(DDD)method.First,LSF not only significantly improved the grain yield per mu,but also significantly improved the labor productivity,income from selling grain,and profits of grain planting.However,LSF unintentionally encouraged those large-scale farmers subsidized by the government to use more chemical fertilizers and pesticides.The mechanism behind these results is that LSF relaxes the credit constraint faced by farmers and consequently improve their incentive to invest more resources,including chemical fertilizers and pesticides,into grain planting.Furthermore,according to the national surface water quality data and air composition data,we find that LSF also improved the level of ammonia nitrogen in the water and nitrogen dioxide in the air in the growing season of food crop,which provides extra evidences for the increasing use of chemical fertilizers by large-scale farmers because of LSF.This paper puts forward the following policy implications for subsidies to LSF.Firstly,subsidy or bank loan support to LSF should exclude the purchase of agricultural materials like chemical fertilizers.It should focus on the purchase of agricultural machinery to improve their labor productivity.Secondly,it is necessary to channel subsides to the adoption of new varieties and green technologies to promote the replacement of traditional chemical fertilizers and pesticides by environment-friendly fertilizers and pesticides,such as slow and controlled release fertilizers,organic fertilizers,biological fertilizers and biological pesticides.Thirdly,mechanical fertilization and the integration of water and fertilizers are encouraged to improve the efficiency of fertilization based on the support of agricultural machinery and water conservancy facilities.The contributions of this paper are twofold.First,as one of literature comprehensively evaluating the effects of the LSF subsidy policy,this paper adopts the DDD method to identify the causal relationship between LSF subsidy and grain production,factor input,pollution of water quality and air due to the increasing use of chemical fertilizers by farmers who are subsidized by the government.It indicates that the LSF policy leads to quantity-quality trade-off on food security in China.The LSF policy not only improves China’s food security and farmers’income,but also significantly stimulates more use of fertilizers and pesticides.This paper sheds light on how to optimize the subside policies in China and other developing economies to achieve a win-win goal,that is,improving both grain yield and avoiding pollution from large-scale farmers’overuse of chemical fertilizers and pesticides.