食品价格、核心通货膨胀与货币政策目标

Food Price,Core Inflation and the Target of Monetary Policy

本文建立了一个多部门新凯恩斯模型来描述食品部门在需求价格弹性、价格粘性和供给冲击等方面的异质性,研究货币政策应该如何应对我国食品价格的较快上涨。本文的研究表明:(1)食品价格粘性较低和食品需求缺乏弹性是导致我国食品价格较快上涨的主要原因;(2)根据福利损失贡献加权法计算的核心通货膨胀是最优的,货币政策盯住这个最优核心通货膨胀能够显著降低外生冲击导致的福利损失;(3)食品价格在这个最优核心通货膨胀中的权重为8.8%,这意味着不应该由于食品具有较大的支出权重而对食品价格上涨过度反应,也不应该由于食品价格具有较高的波动性而对食品价格上涨无动于衷。

This article builds a multi-sector New Keynesian model to describe heterogeneous characters in food sector, including lower price stickiness, smaller price elasticity of demand, and stronger supply shock, and then studies how monetary policy should deal with the rapid rise of food price in China. Our studies show that, （ 1 ） lower price stickiness and smaller price elasticity of demand are main reasons leading to rapid rise of food price; （2） the optimal core inflation measurement is the one calculated by the weighted-average formula in which weights are chosen according to the influence of sectoral inflation on the welfare loss, and monetary policy targeting this core inflation measurement can reduce the welfare loss induced by exogenous shocks; （3） the weight of food price in this optimal core inflation measurement is 8.8% , which implies that, we should not overreact to rapid rise of food price because of its higher expenditure share and not underreact because of its higher volatility.