食品价格冲击与“二轮效应”:基于5种核心CPI的比较研究

Food Price Shock and Second-Round Effects:Competitive Research on 5 Measures of Core CPI

食品价格冲击是否形成"二轮效应"是货币政策是否应该对食品价格冲击做出反应的基础。基于2001—2015年的月度数据,实证分析标题CPI与5种核心CPI之间的动态关系,结果显示:中国标题CPI仅部分回归至核心CPI,这既表明核心CPI不是标题CPI的无偏预测量,也说明食品价格冲击影响了价格设定和通胀预期,形成了一定的"二轮效应"。考虑内生性结构突变后,2009年金融危机之后中国标题CPI回归至核心CPI的速度加快,表明食品价格冲击带来的"二轮效应"影响逐渐减小。但在当前食品占CPI的权重依然很大、食品消费支出占比高等现实背景下,中国货币政策应继续积极应对食品价格波动带来的冲击。

Whether food price shock causes the second- round effects is the fundament of monetary policy should respond or not. This paper uses the monthly data from 2001 to 2015 to analyze the dynamic relationship of heading CPI with 5 core CPIs. The study has found that only part of heading CPI had reverted to core CPI,which means the core CPI is a bias predictor of heading CPI,also it means food price shock has impact on price＇s setting and inflation expectation,and food price shock has informed part of second- round effects. Considering the endogenous structure change,after financial crisis of 2009,the speed of heading CPI revered to core CPI become faster,which means the impact of food price shock become smaller. However,because of the high weight of food in composition of CPI,and the high ratio of food consumption expenditure in household consumption expenditure,the monetary policy should continue to actively respond to food price shock.