Réunion
Official title
Indice des prix à la consommation des ménages urbains de
condition moyenne (Consumer Price Index for Middle-Income Urban
Households).
Scope
The index is computed monthly and covers middle-income
households of all sizes living in Saint-Denis. Middle-income
households are those whose head is a wage earner or salaried
employee in the private or public sector.
Official base
1978 = 100.
Source of weights
The weights and selected items were determined from the results of a
household expenditure survey undertaken in 1986 and 1987 covering the
whole population of Réunion. The consumption used for determining the
weights related only to urban households whose head was a wage earner or
salaried employee.
Weights and composition
| Major groups
| Number of items
| Weights
| Approximate number of price quotations
|
| Food
| 87 | 27.93 | ...
|
| Clothing and footwear
| 49 | 8.60 | ...
|
| Fuel and light
| 6 | 7.16 | ...
|
| Rent
| 1 | 6.27 | ...
|
| Other manufactured goods (furniture, furnishings and other household goods, cleaning materials, etc.)
| 75 | 35.32 | ...
|
| Other services (transport, personal and medical care, etc.)
| 50 | 14.72 | ...
|
| Total
| 268 | 100.00 | 8000
|
Household consumption expenditure
Consumption expenditure for the purpose of the index comprises
most of the payments for goods and services purchased for
consumption by the index population. It includes medical care
and vehicle repairs valued at the actual cost to the household,
as well as car insurance premiums. It excludes direct taxes,
building costs considered as investment, home-produced goods
consumed by households, the value of owner-occupied dwellings and
benefits in kind, which are non-consumption expenditure in
terms of economic accounts.
Method of data collection
The price data are collected by the field staff of INSEE, Direction
Régionale de la Réunion, from 224 retail outlets and service
establishments in Saint-Denis.
The prices are those actually paid, but no account is taken of sale
prices. Prices of meat, eggs, fresh fruit and vegetables are collected
each week, rent data every three months and prices for other goods and
services each monthly. The selection of outlets took into account the
different types of areas in the town of Saint-Denis, of commerce
(such as supermarkets, independent businesses, markets, etc.) and of
purchasing habits.
Housing
Rent data are obtained through a quarterly survey
of a sample of 284 rented dwellings.
Specification of varieties
The list of varieties is modified to take into account
changes in consumption habits, which may be frequent in the case
of food. Items are selected if they are representative of one of
the 268 expenditure headings.
Substitution, quality change, etc.
Three methods are used to take into account quantity or quality changes
in the items priced, the disappearance of old items or the appearance of
new ones: (i) when the new item differs from the old one in terms of
quantity only, the price is adjusted proportionately; (ii) when both
its quality and quantity are different from those of the old one, a
closely-related item is substituted on the assumption that the new item
has the same past price trend as the old one; and (iii) the field staff
themselves make on-the-spot estimates of the price differences resulting
from a quality change.
Seasonal items
Account is taken of the seasonal fluctuations of fresh fruit and
vegetables by varying the items in the sub-group each month while
keeping the overall weights constant. The index compares the
cost of the basket for the current month with that for the same
month of the base year. The base price for a variety is
the weighted annual average for the previous year, which is then used
for each month.
Computation
Since January 1990, the index is a chain index in which the weights are
changed each calendar year. The index for each month is first computed
on base December of the previous year=100; the resulting index is then
calculated on base 1978 = 100 (Laspeyres' chain index).
In computing item indices, price relatives for the current
and base periods are used. Relatives of average prices
are calculated for items with homogeneous varieties, and
averages of price relatives are used for those with heterogeneous
varieties.
Organisation and publication
INSEE, Service départemental de la Réunion: Bulletin de
statistiques
(Saint-Denis).
Idem: L'indice des prix à la consommation des ménages
urbains de condition moyenne
(document No. 33, Oct. 1980).