Volume 1: Consumer Price Indices

Portugal

Official title

Indice de preços no consumidor - series A - Continente General (Consumer Price Index).

Scope

The index is compiled monthly and covers all urban and rural households.

Official base

1983 = 100.

Source of weights

The weights and selected items were derived from a household expenditure survey conducted from March 1980 to February 1981 among a random sample of 8,000 households. The weights were adjusted to reflect price changes between the survey period and 1983.

:hp4.Weights and composition:ehp4.
Major groups Number of items Weights Approximate number of price quotations
Food 188460611461
Clothing and footwear 7310145980
Rent ...(515)...
Housing 7512613876
Medical care 69263748
Transport and communications 411382847
Education and recreation 294121195
Tobacco 512862
Other goods and services 314191286
Total 5111000025455

Household consumption expenditure

This includes goods produced by the household for its own consumption, as well as income in kind. It excludes direct taxes and statutory contributions, unless they can be considered as service fees (e.g. radio and television fees).

Method of data collection

Prices for food items, tobacco and everyday items are collected each day during the last full week of the month. The prices for other items or services are collected each quarter; they are divided into three groups and collected each month on a rotating basis. Education data are obtained once a year, and officially set tariffs are adjusted whenever they change. Prices are collected from 4,800 markets, supermarkets, retail outlets and services in 25 agglomerations. The prices used are those paid directly in the outlets. Special and promotional prices are not included.

Housing

Rent is not used in the monthly computation of the index, although it was taken into account in determining the weights. Rent data are collected by rotation during the second and third quarters of each year for 32,000 dwellings. The rent index is incorporated in the annual index once a year.

Specification of varieties

The characteristics of goods and services are described as fully as possible as regards quality and other physical characteristics, to ensure consistency of data from other establishments.

Substitution, quality change, etc.

If there is a change in quantity, a proportional adjustment coefficient is calculated. If there is a change in quality, the price is estimated by means of a quality coefficient. If there is a change of both quantity and quality, an econometric method is used. When a new item is introduced into the index, its base price is estimated by reference to the price trends of similar items.

Seasonal items

Seasonal variations in the prices of fresh fruit and vegetables are taken into account by varying the items and their weights within a monthly basket, whose overall weight remains constant and by using a 12-month moving average in the final computation of the index.

Computation

The index is computed according to the Laspeyres formula as a weighted arithmetic average with fixed base, using weights corresponding to the base period.

The relative price of each item is computed by dividing the average price for the current period by the average price for the base period. The general index for the continent is a weighted arithmetic average of indices, using as weights the population of each agglomeration, according the 1981 census.

Other information

The A series: Continent Général (published by the ILO) excludes rent; the annual average, including rent, is published by the Instituto nacional de estadistica in Anuario estadistico (Lisbon). The B series refers to the urban populations of Lisbon and Porto.

A new series for the Mainland and a National series (base 1991 = 100) are now computed but the relevant methodological information was not available in the ILO at the time the present volume was published

Organisation and publication

Instituto nacional de estadistica: Annuario estadistico (Lisbon).

Idem: Boletim mensal de estadistica.