Skip to main content

Measures of Underlying Inflation


Measures of underlying inflation (the so-called core inflation measures) -- obtained by removing transitory disturbances from the actual movements observed in the consumer prices -- are frequently used for inflation analysis. Instead of focusing on a specific core inflation measure, a comprehensive examination of various core inflation measures enables us to identify the trends of price movements in a more accurate manner.

The Bank of Japan's Research and Statistics Department releases the following four estimates in line with the monthly release of the official CPI for Japan: the diffusion index of increasing/decreasing items; the trimmed mean; the mode; and the weighted median.

These estimates are, in principle, released at 2:00 p.m., two business days after the release of the official CPI for Japan.

For more information on the estimation procedures and characteristics of these core inflation measures, please see the Bank of Japan Review Series below.

Research Data

Table : Research Data
Date Title Data
June 25, 2024 Charts  [PDF 17KB]
June 25, 2024 Data  [XLSX 55KB]

Explanation and Related Materials

Bank of Japan Review Series

Adjustment for Changes in the Consumption Tax Rate

The consumption tax adjusted CPI is released as reference data by the Statistics Bureau of the Ministry of Internal Affairs and Communications on the following external links.

Notices of Changes

Feb.  9, 2017
Changes in the Data Series and Release Schedule of the Research Data "Measures of Underlying Inflation" 


Charts and data available here are provided to inform some of the Bank of Japan's research and analysis to a wide range of users with interests in economic and financial developments.
Please note that these charts and data are subject to unscheduled changes, revisions, and terminations.
Please contact the Bank of Japan's Research and Statistics Department to request permission when reproducing or copying the content of these charts and data for commercial purposes.
Please credit the source when quoting, reproducing, or copying the content of these charts and data.


Economic Assessment and Projection Group,
Economic Research Division, Research and Statistics Department

Tel : +81-3-3279-1111