Bank of Japan's Research Department publishes new core CPI indicators

The Bank of Japan's Research and Statistics Department has launched the monthly publication of new 'Indicators for Core CPI' data.

This initiative aims to provide a more precise understanding of consumer price inflation by excluding various institutional factors that can distort official figures.

These factors, estimated by the Bank's staff, include changes in consumption tax rates, policies concerning free education, the 2021 reduction in mobile phone charges, travel subsidy programs, and measures to reduce energy costs (e.g., gasoline, electricity, gas).

The data will be presented across three series: 'all items less fresh food,' 'all items less fresh food and energy,' and 'all items less food and energy.'

The definition of these institutional factors may be subject to change without prior notice.

In addition to the newly introduced CPI excluding institutional factors, the Bank of Japan will continue to publish four other key indicators under the 'Indicators for Core CPI' page.

These include the trimmed mean, weighted median, mode, and a diffusion index of increasing/decreasing items.

These four indicators are the same as those previously released under the 'Measures of Underlying Inflation' series.

For a more detailed understanding of their methodologies and analytical applications, the Bank refers to its Review Series publications.

Specifically, 'Core Inflation and the Business Cycle' by Hogen, Kawamoto, and Nakahama (2015-E-6) and 'Performance of Core Indicators of Japan's Consumer Price Index' by Shiratsuka (2015-E-7) provide comprehensive background.