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Home > Statistics > Outline of Statistics and Statistical Release Schedule > Notices of Changes and Corrections 2002 > Modification of the Input-Output Price Index of Manufacturing Industry by Sector in accordance with the revision of the Wholesale Price Index(Switchover to the 2000 Base Corporate Goods Price Index <CGPI>)

Modification of the Input-Output Price Index of Manufacturing Industry by Sector in accordance with the revision of the Wholesale Price Index

(Switchover to the 2000 Base Corporate Goods Price Index <CGPI>)

December 9, 2002
Bank of Japan
Research and Statistics Department

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The Bank of Japan has revised the 1995 base Input-Output Price Index of Manufacturing industry by Sector (IOPI) in accordance with the revision of the Wholesale Price Index (WPI) from 1995 base to 2000 base (switchover of the 1995 base WPI into the 2000 base Corporate Goods Price Index <CGPI>).1 This revision will come into effect from the December 2002 IOPI.

The modification of the IOPI will be as follows:

  1. Price data (Selected commodities)
    The IOPI price data (selected commodities) will be altered to reflect the changes in Commodities under the switchover from the 1995 base WPI to the 2000 base CGPI.
  2. Publication schedule
    Since the CGPI has adopted a new publication system of releasing both preliminary and final figures, the release date of the IOPI monthly index will be two months after the index is compiled, which is one month later than the current publication schedule.
  1. For details, seeRevision of the Wholesale Price Index (Switchover to the 2000 Base Corporate Goods Price Index <CGPI>) released on December 9, 2002. This document is available at the statistics corner of theBank of Japan website.

1. Purpose of the modification

The Bank of Japan has been compiling and publishing the 1995 base IOPI. The IOPI is being modified in accordance with the revision of the WPI from 1995 base to 2000 base (switchover of the 1995 base WPI into the 2000 base CGPI). The IOPI modification affects the price data (selected commodities) and the publication schedule, and will come into effect from the December 2002 index.

Modification of price data (selected commodities)

The IOPI adopts the Commodity indexes of the WPI for its price data (selected commodities). With the switchover of the WPI into the CGPI, the Commodity indexes used for the price data (selected commodities) of the IOPI will also be changed from the WPI to the CGPI.

Under the July 2000 comprehensive revision of the IOPI, the IOPI was changed to compile the index solely based on the Commodity indexes of the WPI. With the switchover of the WPI into the CGPI, it has become necessary to modify the IOPI price data (selected commodities).2

  1. 2For an outline of the revision to the 1995 base, please refer to the following two publications released in July 2000:Revision of the Input-Output Price Index of Manufacturing Industry by Sector (IOPI) to 1995 base andExplanation of the 1995 Base Input-Output Price Index of Manufacturing Industry by Sector (the latter will be revised around January 2003). These documents are available at the statistics corner of the Bank of Japan website.

Change of publication schedule

Since the CGPI has adopted a new publication system of releasing both preliminary and final figures starting from January 2003, the IOPI will be compiled based on the CGPI final figures. This decision was reached because the user needs for preliminary IOPI figures are regarded as low. Accordingly, starting with the December 2002 index, in principle the IOPI release date will be moved to the "eighth working day of the second month after the index is compiled," (at the same time as the publication of the final CGPI figures), which is one month later than the current publication schedule. Up through the November 2002 IOPI, in principle the release date will be the "seventh working day of the following month after the index is compiled" (one day after the WPI publication).

The December 2002 IOPI, which will be the first publication after the switchover to the CGPI, will be released on Friday, February 14, 2003.

2. Details of price data (selected commodities) modifications3

2.1 Modification of correspondence between Commodity and Commodity group

The selected commodities (hereafter Commodities) in the Commodity groups, which are the minimum index compilation units of the IOPI, are being modified to reflect changes of Commodities in the CGPI (e.g., divided and combined commodities)

As a result of modifying the Commodities of the IOPI to reflect the changes in the CGPI, there are some cases where the definitions of certain Commodities inevitably will not exactly correspond to those of their IOPI Commodity groups. It will be necessary to carry out a comprehensive revision of the IOPI to achieve perfect correspondence between the Commodities and the Commodity groups.

Some Commodities that are abolished in the CGPI still remain in the IOPI. Starting with the December 2002 index, which is when the WPI will be switched over to the CGPI, the index of those Commodities will be treated as unchanged from the November 2002 IOPI, which is the last IOPI compiled under the 1995 base WPI. This means that the indexes of some Commodity groups will remain unchanged, but these Commodity groups account for only a minimal share of the overall IOPI.

2.2 Modification of Commodities' weights

The weights of Commodities in the IOPI will remain basically unchanged, except for those Commodities that will be divided or combined in the IOPI in accordance with the changes in the CGPI. Those weights will be changed to approximate the previous Commodities' weights.

2.3 Conversion of the base year and link of Commodity indexes

Starting with the December 2002 index, the Commodity indexes used for compiling the IOPI will shift from the WPI to CGPI. However, since the base year for the CGPI is the year 2000, the base year of the Commodity indexes of the CGPI will be converted from 2000 to 1995 and linked to the November 2002 IOPI of the 1995 base.

  1. 3For further details, see Appendices 1 and 2.

3. Publication schedule of the IOPI after the switchover to the CGPI

The details of the publication schedule of the IOPI are as follows:

Monthly index

In principle, the Monthly index will be released on the eighth working day of the second month after the index is compiled (at the same time as the publication of the final CGPI figures).*

  • Note: For the time being, the IOPI release date will be the "ninth working day of the second month after the index is compiled" to allow extra time for the system maintenance burden resulting from the CGPI revision.

Annual average index (calendar and fiscal year)

In principle, the Annual average index will be released on the day when the last Monthly index for the year is released (in December for the calendar year index and in March for the fiscal year index).

  1. (1) The major monthly index series of the IOPI (indexes of Manufacturing industry sector, Major sector and Aggregated major commodity group) will be released at 8:50 a.m. on the eighth working day of the second month after the index is compiled. This date will be announced in advance at the "releases scheduled for the next four weeks" section of the release schedule corner of the Bank of Japan website. The publication report of the major monthly index series of the IOPI is currently available only in Japanese.
  2. (2) The other detailed index series (indexes of Major commodity group and Commodity group) will be released at 1:00 p.m. on the day when the major monthly index series are released.
  3. (3) All index series, including detailed index series, will be available at the long-term time-series data section of the statistics corner of the Bank of Japan website at 8:50 a.m. on the day after the major monthly index series are released.

The IOPI will carry out periodic retroactive revisions of released indexes in April and October, when the CGPI is revised.

Refer inquiries to:

Price Statistics Division, Research and Statistics Department Bank of Japan

Tel. +81-3-3279-1111 Ext. 3808, 3824