Iran, Islamic Rep. of
Official title
Consumer Price Index.
Scope
The index is compiled monthly and covers 70% of the whole population
of urban areas.
Official base
21 March 1990-20 March 1991 = 100.
The CPI has been available in Iran since 1936.
Source of weights
The weights and selected items were derived from a household expenditure
survey conducted between March 1990 and March 1991, covering 13,000
urban families. Three stage sampling procedure was used.
Weights and composition
| Major groups
| Number of items
| Weights
| Approximate number of price quotations
|
| Food, beverages and tobacco
| 96 | 40.06 | 55000
|
| Other groups:
| ... | ... | 45000
|
| Clothing and footwear
| 42 | 8.07 | ...
|
| Housing, fuel and power
| 25 | 26.20 | ...
|
| House furnishings and household operations
| 41 | 7.24 | ...
|
| Medical care
| 41 | 3.94 | ...
|
| Transport and communication
| 22 | 8.14 | ...
|
| Recreation, education and reading
| 16 | 1.60 | ...
|
| Miscellaneous goods and services
| 20 | 4.75 | ...
|
| Total
| 303 | 100.00 | 100000
|
Household consumption expenditure
The consumption expenditure used for deriving the weights consists
of the money value of all goods and services purchased during the
base year by households for their consumption or given to other
households. It includes the total value at purchase time of durable
goods credit purchases, the value of income in kind (not received from
other households), contributions to social insurance funds, licence
fees, health care, insurance, life insurance payments and expenditure on
gifts. It excludes remittances, direct taxes, contributions to pension
funds and the value of home-produced and consumed goods.
:SAMP.
Items were selected according to therelative importance and availability
of them in the futute. Some randomm sampling methods (PPS) were also used.
The selection of outlets were based on the data collectors' knowledge,
rough estimates of outlets' sales volume, geographical distribution of
the outlets and avilability of ready-made information.
Total number of outlets is 34000 (for food 13000 and for non-food 21000)
Method of data collection
Prices for most items are collected by agents during the first 25
days of each month from retail outlets, supermarkets and service
establishments in 82 cities. In each large city 20 quotations for every
food item and 10 quotations for every non-food item are obtained. The
number of quotaion for the other cities are half of the large cities.
Discounts, sale prices and black-market prices are to be considered.
For items with both official and free-market prices, a weighted average
of prices is computed, using weights derived from the latest household
expenditure survey. Second-hand purchases and hire-purchases are not
included.
Housing
Rent quotations are obtained each quarter from a sample of approximately
8,500 dwellings. The rental equivalence of ownwer-occupied
dwellings is imputed by assuming that it has the same rate of
change as the rental housis (with some quality adjustment) index.
For this hedonic method is used. Rent index is calculated quarterly.
Specification of varieties
For most items, detailed and tight specifications in terms of quality,
make, brand, unit and size are provided centraly. For items which it is
not possible to determine detailed and tight specification, data collec-
tors may select the best selling variety of the item in the outlet.
Substitution, quality change, etc.
Attempts are made to obtain the prices of goods with the same quality
each month. If this is not possible, the nearest quality is priced. If
a quality change is significant, quality adjustment or a linking method
is used.
Seasonal items
When a seasonal item is absent from the market, its price is
imputed by assuming that it has the same rate of change as the
weighted average of the prices of other goods of the group.
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 averages of matched prices are used for deriving price relatives
in consecutive months. The necessary adjustments are made if prices are
incorrect. Missing prices are substituted by prices from other similar
outlets or cities. The index is computed on regional basis.
Other information
The main sub-groups are published. No other national series are
computed.
Organisation and publication
Economic Statistics Department is responsible for collecting price data
and computation of the index. Statistical Researc and Survey Department
is responsible for the methodological aspect of the index.
Economic Report and Balance Sheet
(Teheran).