同比价格指数与环比价格指数辨析

The Differences between Chain Price Index and Year-Based Price Index

同比价格指数与环比价格指数间有着重大的区别,同比指数反映了年度间的价格变化,环比指数反映了月(季)度间的价格变化。实证检验表明,同比价格指数序列与环比价格指数序列有着不同的单整阶数,两者之间不能互相替代。在利用多个宏观经济变量构建月度(或季度)经济计量模型时,不仅要注意各序列的单整性,而且要注意各序列的一致性。

There is a significant difference between year-based price index and chain price index. The year-based price index demonstrates price changes by year to year, while chain price index demonstrates price changes by month to month （or quarter to quarter）. The empirical test has shown that year-based price index has integration ranks different from chain price index, therefore these two price index cannot be replaced each other. When making up monthly （or quarterly） econometric models by means of macro-economic variables, it should be concerned not only their integration ranks but also their consistency.