中国粮食支持政策该向何处去?--来自商品储备模型量化政策评估的证据

粮食安全是社会稳定、经济发展和国家安全的重要基础,粮食支持政策是粮食安全国家战略的核心抓手。过去以托市收储为主要特征的粮食支持政策曾经有效提高了农民种粮积极性和粮食供应能力,但国内市场矛盾累积和多边贸易争端加剧将托市收储推到改革关口。在改革窗口期,跳出国内研究以经验判断、逻辑推演的传统,采用国际农业政策分析中普遍使用的量化评估方法,精确考察和预测粮食支持手段的政策效应,具有迫切必要性、理论和现实意义。基于此,借鉴Wright&William经典商品储备模型(Commodity Storage Model)分析框架,构建一个考虑社会福利动态最优的小麦市场模型,对调低托市价格/取消托市、实行生产者补贴、“托市+生产者补贴”双层政策和补贴私人储备四种改革措施进行了数值优化和模拟分析,从市场稳定、农民保护、粮食安全、财政成本和黄箱限制五维评价指标,详细刻画不同改革措施的改革效果和政策空间后发现:①取消托市、降低托市价格和补贴生产者均会不同程度冲击市场稳定、农民收益和粮食安全。②“托市+生产者补贴”能够以黄箱限制内的成本达到可观的增产增收效果,私人储备补贴高效率与低效果并存。③托市政策具有优良的稳市效果,双层政策则在产量、收入支撑上效果突出。这意味着不应贸然取消托市,改革取向也不应囿于非此即彼式的政策抉择,而应建立多层次粮食支持体系,收缩托市范围并将其后置,增加生产者补贴力度,适度引入私人民间收储以强化效果、降低成本、培育市场,从而在粮食安全保障能力不削弱的前提下,进一步释放市场活力、降低多边贸易争端风险。

Where should China’s grain support policy go?--evidence from the quantitative policy assessment of the Commodity Storage Model

Food security is an important foundation for social stability,economic development and national security,and grain support policy is the core of the national strategy for food security.For a long time,China’s grain support policy with the main feature of Minimum Procurement Price has effectively boosted farmers’enthusiasm for grain production and the capacity of national grain supply.However,the accumulation of conflicts in the domestic market and the intensification of multilateral trade disputes have pushed the policy on the threshold to reform.It is now time to replace the conventional domestic research methods with those that can provide empirical judgment and logical deduction,that is,to use quantitative evaluation methods commonly used in agricultural policy analysis in overseas research to accurately examine and predict the policy effects of grain support options.Based on Wright&William’s Commodity Storage Model,this paper constructed a wheat market model that considers the dynamic optimization of social welfares.This paper accessed four reform measures,namely lowering the Minimum Procurement Price(MPP)/cancellation of MPP,providing Producer Subsidies,implementing‘MPP+PS’policies and providing private storage subsidies(PSS)with numerical optimization and simulation methods.Each of them was evaluated from five-dimensional evaluation indicators:market stability,farmer protection,food security,fiscal cost and amber box constraint.We found that:①canceling MPP,lowering MPP and PSS would threaten market stability,farmers’income and food security to some degree;②‘MPP+PS’policies could achieve considerable increase in production and income by the cost within the WTO Amber box constraint.PSS’s high efficiency coexisted with normal performance;③MPP had a sound effect on market stabilization,and‘MPP+PS’had outstanding performance on production and income support.Therefore,this paper believes that the MPP should not be cancelled hastily.The government should introduce PS as main tool,put MPP at the bottom of agriculture safety nets and subsidize private storage to enhance the effect so as to reduce the costs and cultivate the market.