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Explanation of Indices of Aggregated Sales

September 4, 2006
Bank of Japan
Research and Statistics Department

Table : Explanation of Indices of Aggregated Sales
Compilation section Economic Assessment and Projection, Research and Statistics Department
Frequency of compilation Monthly basis
Time of release Basically at the beginning of every month (two months later)
Method of release Bank of Japan Internet web site
Publications Financial and Economic Statistics Monthly
Commencement of data April 1993

Contents:

(1) Purpose and Functions

"Indices of Aggregated Sales" are the weighted average of major sales indicators, and capture developments in consumption from the side of retailers and service providers.

In detail, the following method is taken to integrate these five sales indicators: (i) Large-scale retail store sales value by type of business, by goods; (ii) New Passenger Car Registrations; (iii) Sales of Household Electrical Appliances; (iv) Outlays for Travel; and (v) Sales of Food Service Industry. The sales indicators are indexed with the base year as 100, and then are averaged with the weights based on spending of households. In order to exclude effects of price fluctuations on sales, each sales indicator is deflated by the Consumer Price Index (CPI).

The indices are convenient in the sense that the trend of these sales indicators can be observed in a single series. However, it should be noted that the indices do not cover a wide range of services consumption, and also do not necessarily incorporate all sales channels of goods.

(2) Released Series

Seasonally adjusted indices in real terms are released for the following two series:

  1. (i) Series including the effects of the increase in the number of stores: this series reflects fluctuations in sales due to changes in the number of stores caused by the opening and closing of businesses. This series includes sales of convenience stores.
  2. (ii) Series excluding the effects of the increase in the number of stores: this series aims to capture sales only in stores whose data can be obtained continuously. It is calculated by using published year-on-year changes of the sales indicators which are adjusted for the changes in the number of stores. Note that, however, it does not include sales of convenience stores due to data limitation.

Long term time-series data for Indices of Aggregated Sales are updated every month when new figures are released. We recommend using those up-to-date data on the web site. Figures for past and present months are preliminary, based on information available at the time of the release, and hence may be often revised due to revision of data for sales indicators.

(3) Methodology

According to the categories below, sales of each item are deflated by the corresponding deflators, except for "automobiles" where number of automobiles are directly used as figures in real terms. Then, each item is summed up by the categories and is indexed with the base year as 100. Finally, each category is averaged with the weights based on consumption spending in the Family Income and Expenditure Survey of 2005.

(4) Seasonal Adjustments

X-12-ARIMA is used for seasonal adjustments. Every year when figures for March are published, seasonally adjusted figures in the past periods are renewed. For the following year, monthly seasonally adjusted figures are calculated using expected seasonal factors.

<Reference tables on Items etc.>

1. Items
Category Items Reference Materials
Food Large-scale retail store sales value by type of business, by goods (Sales of food & drinks at department stores, supermarkets, and convenience stores) Current Survey of Commerce (Ministry of Economy, Trade and Industry)
Clothes Large-scale retail store sales value by type of business, by goods (Sales of clothes at department stores and supermarkets) Current Survey of Commerce (Ministry of Economy, Trade and Industry)
Furniture Large-scale retail store sales value by type of business, by goods (Sales of furniture at department stores and supermarkets) Current Survey of Commerce (Ministry of Economy, Trade and Industry)
Electric Appliances Sales of household machinery retail stores Current Survey of Commerce (Ministry of Economy, Trade and Industry)
Automobiles New Passenger Car Registrations excluding mini vehicles with sizes of 660 cc or less Domestic Sales of Automobiles (Japan Automobile Dealers Association)
Mini Vehicles New Passenger Car Registrations of mini vehicles Sales of Mini Vehicles (Japan Mini vehicles Association)
Eating Out Sales of Food Service Industry Gaishoku Sangyou Shijou Doukou Chousa <The Research of Food Service Industry> (Japan Food Service Association)
Travel Outlays for Travel (Domestic & Overseas) Major Travel Agents' Revenue (Ministry of Land, Infrastructure and Transport)
2. Deflator: "Consumer Price Index (CPI)" of the Ministry of Public Management, Home Affairs, Posts and Telecommunications is used for the items below. Within each category, items are basically summed taking simple weighted averages. For Electric Appliances, however, geometric means is used in order to prevent rapidly-decreasing prices of computers from giving aggregation bias to the deflator of the category.
Category Name of category and item in CPI
Food Food (excludes Eating out)
Note: deflator for sales of convenience stores is Food <excludes Eating out, Fresh fish & shellfish, Fresh meat, Fresh vegetables, and Fresh fruits>.
Clothes Clothes & footwear, Personal effects (excludes Wrist watches, Repair charges of wrist watches).
Furniture General furniture, Carpets, Curtains.
Electric Appliances Domestic durables, Heating & cooling appliances, Lighting apparatus, Fluorescent lamps, Bathroom scales, Thermometers, Sphygmomanometers, Telephone set, Cellular phones, TV sets (CRT), TV sets (LCD), Stereo phonograph sets, Mobile audio equipment, DVD recorders, Personal computers (desktop), Personal computers (notes), PC printers, Cameras, Video cameras, Films, Recordable DVD media, Dry batteries, Electric shavers.
Note: Consumer Price Index, Domestic Wholesale Price Indexes and Corporate Goods Price Index are used as a deflator for categories don't exist.
Eating Out General meals
Travel Hotel charges, Ordinary fares excluding "Shinkansen", Ordinary fares for "Shinkansen", Special fares excluding "Shinkansen", Special fares for "Shinkansen", Ordinary passengers, Airplane fares, Package tours to overseas (since 2000).
3. Weights: Expenditures (Year 2005) of "The Family Income and Expenditure Survey (All Households not including agricultural, forestry and fisheries households)" of the Ministry of Public Management, Home Affairs, Posts and Telecommunications used for the items below:
Category Name of category and item in
"The Family Income and Expenditure Survey"
Food Food (excludes Eating out)
Note: weight for sales of convenience stores is Food <excludes Eating out, Fresh fish & shellfish, Fresh meat, Fresh vegetables, and Fresh fruits>.
Clothes Clothes & footwear, Personal effects (excludes Wrist watches, Services related to personal effects).
Furniture General Furniture, Floor coverings.
Electric Appliances Domestic durables, Heating & cooling appliances, Lighting appliances, Electric bulbs & fluorescent lamps, Other medical supplies & appliances, Mobile telephone, Other communication equipments, TV sets, Stereo phonograph sets, Equipment for receiving, recording & play-back of sound & pictures (portable), Video recorders, Personal computer, Cameras, Video cameras, Films, Unrecorded recording media, Dry battery, Electric appliances for personal care.
Automobiles Automobiles
Eating Out General meals
Travel Package tours