Thailand
Official title
General Consumer Price Index.
Scope
The index is computed monthly and covers families living in urban
areas, with two to ten persons, and with monthly
expenditure of 4,000 to 10,000 bahts in 1986.
Official base
1986 = 100.
Source of weights
The weights and selected items were derived from a household
socio-economic survey conducted in 1986 in the whole country covering a
sample of all private non-institutional households. The items were
selected on the basis of their relative importance in the household
expenditure pattern, the degree to which a given item can represent the
price changes of a larger group of items, the variability of price
changes among the group in which an item was classified, the degree to
which an item can be identified reliably by specification and the
anticipated demand which would increase the relative importance of the
item in the future. Expenditure for unpriced items which were similar
to priced items in terms of physical characteristics and use were added
to the expenditure for the priced items. Expenditure for other unpriced
items in a specific sub-group was distributed proportionately for each
sub-group. All miscellaneous expenditure not classified in any
sub-group was distributed proportionately to all priced items. The
number of items and the weights used since 1991 are as follows:
Weights and composition
| Major groups
| Number of items
| Weights
| Approximate number of price quotations
|
| Food
| ... | 40.38 | ...
|
| Housing:
|
| Shelter, Furniture and household appliances
| ... | 24.76 | ...
|
| Clothing and footwear
| ... | 4.77 | ...
|
| Medical and personal care
| ... | 5.13 | ...
|
| Transport and communication
| ... | 8.94 | ...
|
| Recreation and education
| ... | 11.69 | ...
|
| Tobacco and alcoholic beverages
| ... | 4.33 | ...
|
| Total
| ... | 100.00 | ...
|
Household consumption expenditure
Consumption expenditure for the purpose of the index comprises
the purchase of goods and services, the value of goods and
services received as part of pay, received free, home produce and
the rental value of owned home. It excludes direct taxes
paid to the government, cash gifts and contributions, insurance
premiums, purchase of lottery tickets and other forms of
gambling, interest on debts and shares and all forms of assets
and liabilities.
Method of data collection
Prices are collected by agents from market centres, retail
outlets and service establishments in urban areas. Prices for
food items are collected each week from at least four retail outlets
in each market area. Prices for other items are collected during
the week which includes the 15th of the month. Telephone
charges, electricity, water rates, hospital charges, etc., are
obtained from government agencies. The prices used in the index
are those that any member of the public would have to pay on the
pricing day.
Housing
The rental value of owner-occupied dwellings is added to the
expenditure weight for rents. The price change is measured by
the change from period to period in average rents paid. These
are obtained each quarter from a sample of about 355 tenants.
Specification of varieties
The specifications describe the variety, quality, make, brand
etc.
Substitution, quality change, etc.
If the characteristics of a product are altered, a method
of linking is used. If an item disappears from the market, it
is replaced by a similar item.
Seasonal items
No account is generally taken of seasonal fluctuations in item
prices. For certain items, fluctuations are taken into account by
maintaining the closing prices of
the previous season during the off season.
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.
In practice, however, the index is a monthly chain
computation of base weights and price relatives for two
consecutive periods. In this computation, the index for the
previous month is updated to obtain the index for the current
month.
The nationwide index is an aggregation of the regional series
weighted by the population weight of each region.
Organisation and publication
The index is computed each month by the Ministry of Commerce,
Department of Business Economics, Price Index Division (Bangkok).
Idem: Monthly Report Consumers Price Index
.
Office of the Prime Minister, National Statistical Office:
Bulletin of Statistics
(Bangkok).