Expanding the use of Big Data for CPI in Japan

The Statistics Bureau of Japan (SBJ) has been utilizing big data to calculate the consumer price index (CPI) and has greatly expanded the scope since the 2020-base year. In the 2015-base year, the index was calculated using scanner data for four items: “personal computers (laptop)”, “personal computers (desktop)”, “tablet computers” and “cameras”. From the 2020-base, three items, “video recorders”, “PC printers” and “TV sets” were added to the index using scanner data. The SBJ has been conducting experimental studies and pilot tests for the use of web scraping since 2015, and from the 2020-base, began actually producing indices for travel services (“airplane fares”, “hotel charges” and “charges for package tours to overseas”). By expanding coverage, the use of big data has made it possible to produce more appropriate indices, with the number of prices increased significantly compared to previous field surveys, and to reduce the burden on local governments and price collectors. This paper introduces a comparison of the 2020-base results using big data and the 2015-base results using field surveys for the same items, as well as the current status of studies aimed at expanding the use of big data.