全球经济政策不确定性对中国粮食价格波动的非线性影响

The nonlinear impact of global economic policy uncertainty on Chinese food price fluctuations

推动粮食价格保持在合理水平是稳步提升粮食综合生产能力并保障国家粮食安全的重要举措。该文将全球经济不确定性指数、国际原油价格和国际粮食价格等外部因素纳入经济政策不确定性的研究框架,构建时变参数自回归模型,实证分析全球经济政策不确定性对中国粮食价格波动的非线性影响。该研究表明:全球经济政策的不确定性对中国粮食价格产生了不同方向的影响,在经济增长期表现为价格上涨,在经济低迷期则导致价格下跌。此外,该不确定性还显示出一种不对称特征,即在经济形势较好时,主要影响玉米、小麦和大豆的价格;而在形势较差时,则更多地影响到大米的价格。国际石油和粮食价格在高位区制下对小麦、玉米和大豆的冲击更显著。对此,该文提出推进中国粮食市场供给侧结构性改革、制定差异化国家粮食宏观调控政策体系和构建全球视野下的国家粮食安全战略等政策建议。

This article incorporates external factors such as the global economic uncertainty index,international crude oil prices,and international food prices into the research framework of global eco-nomic policy uncertainty,and constructs a TVAR(time-varying autoregressive)model to empirically analyze the nonlinear impact of global economic policy uncertainty on China's food price fluctuations.Research shows that global economic policy uncertainty has a non-uniform impact on China's grain prices,with positive and negative effects under low and high level regimes,respectively.The asymmet-ric impact of global economic policy uncertainty is manifested as a significant impact on corn,wheat,and soybeans under the high-level zone system,and a significant impact on rice under the low-level zone system.The impact of international oil and food prices on wheat,corn,and soybeans is more significant under the high regional system.