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Outline of Corporate Service Price Index (CSPI, 1995 base)


July 2004
Bank of Japan
Research and Statistics Department

1. Purpose and uses

The CSPI focuses on the prices of services traded among companies. The CSPI can be regarded as a counterpart of the CGPI, which focuses on the prices of goods traded among companies. The main purpose of the index is to investigate price movements that reflect most sensitively the supply and demand conditions in the services market, with a view to facilitating analyses of macro-economic conditions. The indexes of less-aggregated levels (e.g., item) also have a "deflator" function that transforms nominal output values into real quantities.

2. Classification and weights

The CSPI covers domestic and imported services provided for companies,*1 and excludes services provided for consumers.*2, *3 The weights of the index are based on the transaction values of services during the base year 1995 within the total intermediate sectors of the Input-Output Tables (I-O Tables), published by the Management and Coordination Agency (the Ministry of Public Management, Home Affairs, Posts and Telecommunications since January 2001). The CSPI is classified into 8 Major groups and further classified into 17 Groups.

  1. *1Some reference index series cover exported services.
  2. *2Services for which it is difficult to conduct reliable continuous price surveys and whose weights should not be imputed to other services selected in the index because of the absence of similar services in terms of characteristics or price developments are excluded (e.g., financial services <imputed interest>, wholesale and retail trade, education and research, public administration).
  3. *3Services mainly provided for consumers are included in the CSPI when they are demanded not only by consumers but also by companies (e.g., telephone calls, postal services).

3. Base year for the index and the weight calculation

The base year is 1995 for both the index calculation and the weight calculation.

4. Selection of items

First, services in Basic sectors of the I-O Tables whose transaction values of total intermediate sectors are no less than 500 billion yen (about 0.5% of the "transaction values of the index" during the base year 1995), are selected as Subgroups. Second, in each Subgroup individual services, for which value data for calculating index weights are available and for which adequate sample prices can be collected continuously, are selected as Items. The CSPI covers a total of 102 Items.

5. Sample prices

In principle, sample prices are surveyed at the time of contract. In conducting price surveys, the foremost consideration is given to the following points: 1) Prices most sensitively reflecting the supply and demand conditions of the service transactions should be chosen as sample prices. 2) The price movements of surveyed services need to be as genuine as possible. They should be free from price changes caused by changes in the services' quality or contract conditions. The number of sample prices is 2,942 (as of December 2001).

When sample prices are contracted in foreign currencies, they are converted to a yen basis for the yen-basis index compilation using monthly average spot exchange rates (foreign currency selling rates for imports and buying rates for exports and domestic transactions) as quoted by banks to customers in each corresponding month. For details, refer to column 6, "Sample prices for the CGPI."

The CSPI includes the consumption tax.

6. Index formula

The index formula is the fix-weighted Laspeyres formula. For details, refer to column 7, "Index formula for the CGPI."

7. Publication

In principle, the CSPI is released on the 18th working day of the following month after the surveyed month of the index. The release date will be shifted a few working days earlier, when the number of working days in the month is small. Periodic retroactive revisions of published indexes are implemented twice a year in April and October, when the March and September indexes are released. The published indexes are revised for the past one year in principle. Apart from these periodic retroactive revisions, the CSPI will be revised immediately if a large enough error (such as one resulting in changes at the index level of All items) is found in the published indexes.