我国食品价格对CPI的非线性冲击及其政策启示——基于STR模型的实证研究

The Nonlinear Impact of Food Price on the CPI in China and Its Policy Implications——An Empirical Study Based on STR Model

文章基于2002年2月至2016年5月的食品价格和CPI数据,利用平滑转换回归模型刻画我国食品价格对CPI冲击的非线性特征。结论表明:食品价格对CPI的冲击具有非线性性,即当食品价格变动小于门槛值-1.2157或大于门槛值1.1031时,当月食品价格对当月的CPI将产生更强的同向推动作用;CPI受到食品价格影响容易从低水平快速攀升;我国通货膨胀具有一定的惯性,通货膨胀具有自我强化的作用。研究结果的政策启示在于:政策制定者应关注食品价格对CPI冲击效应的门槛值,把握主动权;当CPI上涨过快时,更要果断采取措施,预防食品价格上涨对CPI的快速扩散;决策部门应密切关注食品价格对CPI影响的累积效应。

Based on the data of food price and CPI from February 2002 to May 2016, this paper attempts to use the STR model to research the nonlinear impact of food price on the CPI in China. The results show that： The impact of food price on CPI is nonlinear, namely when the change in food price is less than the threshold value- 1.2157 or greater than the threshold value 1.1031, food price will produce a stronger promoting effect on CPI in the same month; CPI easily and quickly climbs up from a low level when affected by food price; Inflation has a certain inertia in China, it also has a self-reinforcing effect. The policy implications of this study are： the policy makers should pay attention to the threshold value of the shock effect of food price on CPI, grasp the initiative; When CPI is rising too fast, the policy makers should take decisive measures quickly to prevent the negative effect of rising food price on the overall price level; The policy makers should pay close attention to the cumulative effect of rising food prices on CPI.