The present Volume 1 of Sources and Methods: Labour Statistics provides methodological descriptions of national consumer price indices published by the ILO in the 1992 editions of the Year Book of Labour Statistics and the Bulletin of Labour Statistics. It is a revised, enlarged and updated version of the second edition of Statistical Sources and Methods issued in 1987.

This volume contains descriptions of 171 consumer price series in respect of 157 countries. Most of the descriptions were prepared from the official replies from national statistical offices to a specifically designed questionnaire and/or from national publications on consumer price indices. In certain cases, the descriptions presented may relate only to new series published in the Bulletin pending the availability of annual averages to be published in a later issue of the Year Book.

The volume has two main purposes: (i) to provide basic information on the sources and methods used in each country in compiling the consumer price indices published by the ILO, so as to enhance their usefulness for different purposes; and (ii) to indicate the differences between the various national series with regard to their scope, coverage, sources of data, definitions, classifications, the treatment of selected special problems and the formula used for computation. The descriptions have been structured and presented using 14 standard headings for the different characteristics in order to facilitate comparisons. These headings are as follows.

Official title

The title of the consumer price index in the language used in official correspondence between the country and the ILO and, if necessary, its English translation.

Scope

Information is given on the periodicity of the series (monthly, quarterly, half-yearly or yearly); the types of household covered in terms of households within a given income or expenditure class or households of a specific size; the population groups covered, which may refer to the whole population or specific socio-economic groups such as industrial workers, non-manual employees, etc.; and the geographical areas covered, such as the whole country, urban centres, the capital city, specific towns or a group of towns.

Official base

The base year or period used in the original computation of the index, and its presentation in national publications.

Source of weights

The source(s) and the reference period of the weights used for the index, e.g. a household expenditure survey, national accounts, etc. If the reference period for the weights differs from the base period of the index, the adjustments made to the weights to take account of the price changes between the two periods are described.

If the weights were derived from a household expenditure survey, information is provided about the types of household, population groups and geographic areas covered, the duration of the survey, the reference period for expenditure data and the sample size. If the weights were obtained from the national accounts or other sources, the methods of deriving them are given, wherever possible. The criteria and the method used for selecting index items or for dealing with items not priced (imputation of weights) are also described.

Weights and composition

The number of items and the weights used to compute the index are given according to expenditure group. The term "item" is used here to mean the smallest grouping of goods and services for which a specific weight is given. For example, beef might be an item represented by several varieties such as round steak, sirloin steak, etc., for which separate weights are not available. The following major groups are distinguished: food; fuel and light; clothing; housing; and miscellaneous. However, if the national classification does not conform with the above groupings, the actual classification used by the country is given. Where possible, the approximate number of price quotations used for computing the index is indicated.

Household consumption expenditure

Household consumption expenditure is generally defined as the expenditure incurred by private households on consumer goods and services. It may refer to actual purchases or to actual consumption. The descriptions explain, wherever possible, the treatment of home-produced goods consumed by the household, home ownership, durable goods credit purchases, second-hand purchases, contributions to social insurance and pension funds, licence fees, insurance associated with specific consumer goods, health care, income and other direct taxes, life insurance payments, remittances, gifts and other similar disbursements.

Method of data collection

The methods used for selecting localities and outlets; the frequency with which prices are collected for different categories of goods and services; the treatment of discounts, sale prices, black-market prices, hire-purchase or credit terms, second-hand purchases, import prices and indirect taxes; the methods of collecting prices for different types of item (visits to outlets, mail questionnaires, official tariffs, actual purchases); and special techniques used for price collection in respect of such items as electricity, gas and water, medical care, education or transport and communication.

Housing

The methods used to obtain data on rents, as well as the treatment of owner-occupied dwellings. The treatment of disbursements such as rates, insurance, mortgage interest, repairs, etc., and the methods and frequency of collecting the data are indicated when information is available.

Specification of varieties

Specifications are the criteria used to describe precisely the variety being priced. These could be in terms of quality, make, brand, unit, etc. The procedure used to identify the varieties when there are no detailed and tight specifications is indicated.

Substitution, quality change, etc.

The appearance of a new product on the market, and the disappearance of an item or quality changes affect the index. The methods used by countries to deal with these problems are described briefly.

Seasonal items

If the index includes items such as fresh fruit and vegetables which experience seasonal fluctuations in their prices or availability, the procedures used to deal with these seasonal influences are briefly noted.

Computation

The price data for the different items included in the computation of the index are normally weighted in order to take into account the relative importance of each item with respect to total consumption expenditure. In most countries, the indices are computed in a derived form such as weighted arithmetic averages of price relatives for a selected number of representative items between the period under consideration and the base period, using one or other forms of Laspeyres' formula. The descriptions explain the exact methods used by the countries wherever these are known. A few countries use a Laspeyres' chain index with yearly links or Paasche's formula for computing their indices. These are indicated in the descriptions.

The methods of calculating the average prices and price relatives, as well as whether the index is computed directly or as an aggregation of local or regional indices, are also described.

Other information

Where available, complementary information is furnished concerning the publication by the country of various sub-groups of the index, or the computation of series for other population or income groups or other geographical areas.

Organisation and publication

The statistical authority responsible for computing and publishing the index, as well as the titles of the major current national publications in which the index appears, are given under this heading. Wherever possible, the titles and sources of national publications providing detailed methodological descriptions of the series are also indicated.

List of tables published by the ILO

A. Year Book of Labour Statistics:

Consumer Prices:

23 General indices

24 General indices, excluding shelter

25 Food indices

26 Fuel and light indices

27 Clothing indices

28 Rent indices

B. Bulletin of Labour Statistics:

9A General indices

9B Food indices

Remarks

As the original base period of the series varies between countries, a uniform base period has been adopted for the presentation of the data in ILO publications. Since 1986 this base period has been changed to the year 1980. (If data are available only for periods subsequent to 1980, the indices are generally shown with the first calendar year for which the figures are available as the base period and are printed in italics.) This operation involves no change in the weighting system used for the computation of the series.

Signs and symbols used

.

Not applicable

...

Not available

-

Nil or less than half of unit employed

(a)

Footnote to table

In the tables, decimal points are indicated by a full stop.