核心通货膨胀：理论模型与经验分析

Core Inflation:Theoretical Model and Empirical Analysis

现有的核心通货膨胀计算方法假设各种商品和服务的价格变化可以表示为核心通货膨胀与异质性相对价格变化之和,然而这种价格变化的分解方式既缺乏理论基础又违背经济直觉。本文将经典的新凯恩斯模型推广到多部门情形,证明了多部门新凯恩斯菲利普斯曲线,提出了各部门商品价格变化的理论分解公式。以这个分解公式为理论基础,本文提出了估计核心通货膨胀的计量经济模型及其两阶段估计方法,给出了根据稳态权重估计核心通货膨胀的简便方法,估计出了我国的核心通货膨胀。有效性检验表明,根据两阶段估计方法和基于稳态权重的估计方法得到的核心通货膨胀都是有效的核心通货膨胀度量。

Existing measurement methods of core inflation assume that price change of each goods and serves be expressed as the sum of core inflation and idiosyncratic relative price change. However, this assumption has no theoretical base and violates economic intuition. This article generalizes the classical new Keynesian model into a multi-sector economy, proves new Keynesian Phillips curve in a multi-sector economy, puts forward a formula decomposing sectoral price changes based on firms＇ optimal decision. Based on this formula, this article puts forward an econometrics model of core inflation and its two-stage estimation method, gives a simple calculation method of core inflation using steady-state weights, estimates core inflation in China. Effectivity test shows that, using two-stage estimation method and method based on steady-state weights can get effective core inflation measurements.