中国CPI感知偏差再评估:新视角、新方法与新证据

A Reevaluation of China’s CPI Perceptual Bias: New Perspective, New Method and New Evidence

如何理解统计部门CPI与家庭通胀感知之间的背离现象始终是经济学研究的重点和难点。本文首先质疑了恩格尔曲线法核心假设,进而测度中国各省市感知偏差,最后从三个颇具争议且颇为有趣的角度探讨了感知偏差成因。实证结果显示:第一,中国耐用消费品的质量增速约为5.74%(其中,77%被误记为通胀),显著高于其他经济体。相比之下,食品质量增速仅为0.19%。因为耐用消费品占比较低,所以质量偏差对于感知偏差的影响有限。第二,与常规观点不同,利用较为规范的方法调整食品权重和居住权重固然会导致通胀低估,但是影响程度仅为1%左右。第三,感知偏差主要存在于无房家庭,对于多套房家庭,其感知偏差近乎为0,这意味着住房价格波动很可能是感知偏差的主要原因。本文认为,作为CPI的有益补充,积极编制反映家庭主观感知的生活成本指数恰逢其时。

How to understand the deviation between CPI and the perception of cost-of-living has always been the focus in economic research.This paper challenges the core assumption of traditional methods,re-measures the perceptual bias at the provincial level,and explores the causes of biases from three controversial and interesting perspectives.We find that:Firstly,the growth rate of the quality of durable goods is 5.74%(of which 77%is mistakenly recorded as inflation),which is relatively higher than that of other countries.In contrast,the growth rate of food quality is only 0.19%.Since durables account for a low proportion in the consumption basket,the impact of quality bias is limited.Secondly,countering conventional wisdom,the magnitudes of underestimation of CPI caused by the weight of food and housing items are just around 1%.Thirdly,the perceptual bias mainly exists in households without houses.For households with more than one houses,the perceptual bias is around 0,indicating that the fluctuation of asset price is the main cause of perceptual bias.As a useful supplement to CPI,we suggest compile an index of cost of living with households’perceptions.