Isle of Man
Official title
General Index of Retail Prices.
Scope
The index is compiled monthly covering all private households,
excluding 3-4 per cent of the top income group and the lowest
group receiving social assistance.
Official base
March 1976 = 100.
Source of weights
The weights and selected items were derived from the household
expenditure survey conducted in 1976 among a random sample of
households.
Weights and composition
| Major groups
| Number of items
| Weights
| Approximate number of price quotations
|
| Food
| ... | 244 | ...
|
| Alcoholic beverages
| ... | 82 | ...
|
| Tobacco
| ... | 53 | ...
|
| Housing
| ... | 104 | ...
|
| Fuel and light
| ... | 90 | ...
|
| Durable household goods
| ... | 66 | ...
|
| Clothing and footwear
| ... | 72 | ...
|
| Transport and vehicles
| ... | 134 | ...
|
| Miscellaneous goods
| ... | 64 | ...
|
| Services
| ... | 59 | ...
|
| Meals outside home
| ... | 32 | ...
|
| Total
| 450 | 1000 | ...
|
Household consumption expenditure
Consumption expenditure for the purpose of the index includes
almost all goods and services purchased by the index population.
It excludes contributions to pension funds, income and other
direct taxes, cash gifts and life insurance payments.
Method of data collection
Prices are collected from about 100 selected retail outlets and
service establishments by agents, mail questionnaires or
telephone enquiry. Price are collected each month on the
Tuesday nearest to the middle of the month.
The prices used to calculate the index are the prices actually
paid. Discounts and reduced prices available only to
certain members of the public are not taken into account. Sale
prices, special offers, etc., are taken into consideration if the
product concerned is of the usual size and quality.
Housing
Rent data are obtained from a small number of representative
dwellings.
Specification of varieties
The specifications of items to be priced are given in terms of
brand, quality and size, etc.
Substitution, quality change, etc.
Account is taken of changes occurring in similar products in
order to distinguish genuine price increases from changes in
quality, and judgement is used to identify these.
Seasonal items
In the case of fresh fruit and vegetables, a fixed weight for the
sub-group is distributed over item weights which vary each month.
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.
Organisation and publication
Treasury's Economics Section: Index of Retail Prices
(Douglas).
Idem: Digest of Economic and Social Statistics
.