中国消费价格指数季节变动的函数性数据分析

Research on the Seasonal Fluctuation in CPI of China by Functional Data Analysis

运用函数性数据分析方法对中国从1990年1月到2009年12月期间的消费价格指数的季节变动特征进行了分析,结果发现中国消费价格指数存在季节性,一般年份对应的相平面图呈现相似的几何结构;基于傅里叶基函数组合给出的拟合函数较好地刻画了消费价格指数的季节变动特征。另外,中国物价水平具有惯性特征,其在受到一个结构性冲击的影响偏离正常水平之后,大约在一个季度回复到正常水平。

With functional data analysis,this paper has analyzed the seasonal fluctuation in CPI of china from January 1990to December 2009.The results obtained are that the seasonal fluctuation does exist in CPI of china and the phase plots takes on similar geometric structure.The fitted function defined by Fourier base functions depicts the seasonal fluctuation better.In addition,the price level of china possess inertial characteristic.It will return to normal level within one quarter when the price level shocked by a structural shock and departs from its normal level.