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
| 188 | 4606 | 11461
|
Clothing and footwear
| 73 | 1014 | 5980
|
Rent
| ... | (515) | ...
|
Housing
| 75 | 1261 | 3876
|
Medical care
| 69 | 263 | 748
|
Transport and communications
| 41 | 1382 | 847
|
Education and recreation
| 29 | 412 | 1195
|
Tobacco
| 5 | 128 | 62
|
Other goods and services
| 31 | 419 | 1286
|
Total
| 511 | 10000 | 25455
|
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
.