Jamaica
Official title
Consumer Price Index.
Scope
The index is compiled monthly and covers households in urban and
rural areas with an annual income of 24,000 dollars or less at the time
of the survey.
Official base
January 1988 = 100.
Source of weights
The weights and selected items were derived from a household expenditure
survey conducted in 1984 in urban and rural areas among households with
an annual income of 24,000 dollars or less at the time of the survey.
Item sub-groups representing less than 0.50 per cent of expenditure
within a group in all regions were left out and their weights
redistributed among the other sub-groups. The same selection criterion
was applied to the items in each sub-group, exception for the Food and
drink group, where the cut-off point for each item was 0.40 per cent.
Weights and composition
| Major groups
| Number of items
| Weights
| Approximate number of price quotations
|
| Food
| ... | 55.63 | ...
|
| Fuel and household supplies
| ... | 7.35 | ...
|
| Rent and household operation
| ... | 7.86 | ...
|
| Furniture and furnishings
| ... | 2.83 | ...
|
| Medical care
| ... | 6.97 | ...
|
| Clothing and footwear
| ... | 5.07 | ...
|
| Transport
| ... | 6.44 | ...
|
| Miscellaneous
| ... | 7.85 | ...
|
| Total
| ... | 100.00 | ...
|
Household consumption expenditure
Not available.
Method of data collection
Prices for most items are collected during the first weekend of
each month from a fixed set of outlets throughout the island.
Doctors' and dentists' fees are collected each quarter, school fees
each term and health insurance once a year. Changes in the cost
of telephone rates, water rates and bus fares are recorded when
announced. The Institute's team of field officers are responsible for
collecting the prices from various sources including supermarkets,
department stores, footwear stores, restaurants, service stations,
doctors and dentists, clubs, schools, hair-dressers and barbers. Items
such as electricity and telephone charges are collected from the
authorities concerned while information on rent is obtained from a
sample of dwellings.
The outlets are visited each month by the agents. The respondent
outlets are located in areas commonly used by the target group and are
typical of the types of the outlets they patronise. They were not
selected at random, but rather a purposive or judgement sample was
selected in collaboration with the experienced field officers who have a
very good knowledge of the area covered and general popularity of the
stores with the target population. The outlets were chosen on the basis
of volume of sales. The selection process was not restricted to larger
establishments; small grocery shops and small stores within communities
where people buy when they are out of stock are also included in the
sample.
The prices charged for stale, damaged, shop-soiled or otherwise
imperfect goods are ignored since they represent a departure from the
given specifications. If illegal prices are charged openly to the
groups covered by the index, they are taken into consideration.
Housing
Rent quotations are obtained each month from a sample of specific types
of houses with regard to the number of bedrooms and other rooms.
Household payments such as mortgage down payment, repayments and
interest charges, and home insurance represent the user cost of
owner-occupied dwellings, i.e. cash outlays are used as a proxy for the
estimated rental value. The price index used to arrive at a quantum
covers the rents of the representative categories of dwellings.
Specification of varieties
Items for which prices are collected are clearly specified to
ensure that items of comparable quality are priced every month.
Substitution, quality change, etc.
A commodity or service maybe observed to be disappearing from the market
and a new one entering it. If there is an overlap of price observations
and a quality difference is evident, the following linking method is
employed: a base period price is imputed for the new variety using price
relatives for the current and base periods.
However, if the old and new varieties are of comparable quality, the
price of the new one is taken and the difference in price treated as an
increase or decrease. If the consumer has no choice but to buy the new
variety, the difference in price is treated as a price change and not as
payment for a higher or lower quality, even if there is a utility
differential.
The appearance of truly new products (i.e. products not
replacing any item in the index) which bring about significant
readjustments to the consumer budget is rare; if this occurs,
a revision of the index is necessary.
Seasonal items
No adjustment is made to seasonal fluctuations of item prices.
Computation
The index is computed according to the Laspeyres formula as a
weighted arithmetic average with fixed base, using weights
corresponding to 1984. The price relative for each item is
calculated by dividing the average price for the current period by
the average price for the base period. A weighted average of the
three regional indices is calculated to obtain the all-island
index.
Organisation and publication
Statistical Institute of Jamaica: Consumer Price Index Monthly
Bulletin
(Kingston).
Idem: Consumer Price Index Monthly Report
.
Idem: Consumer Price Index - Annual Review
.