Kenya (Nairobi)
Official title
Consumer Price Index - Lower Income Group.
Scope
The index is compiled monthly and covers households in
Nairobi with a monthly income of up to 1,999 shillings in
1982-83.
Official base
February-March 1986 = 100.
Source of weights
The weights and selected items were derived from a household expenditure
survey conducted during 1982-83 in all urban centres. The sample
comprised 1,648 households of low-, middle- and high-income groups. The
index relates to low-income group households in Nairobi with a monthly
income of up to 1,999 shillings at the time of the survey. The weights
were not adjusted to take into account price changes between the survey
period and February-March 1986.
Weights and composition
| Major groups
| Number of items
| Weights
| Approximate number of price quotations
|
| Food
| 49 | 44.2 | ...
|
| Beverages and tobacco
| 11 | 2.1 | ...
|
| Clothing and footwear
| 34 | 5.0 | ...
|
| Rent
| 1 | 25.0 | ...
|
| Fuel, light and water
| 4 | 3.1 | ...
|
| Furniture, furnishings, household equipment and operation
| 29 | 5.3 | ...
|
| Health and personal care
| 18 | 3.0 | ...
|
| Transport and communication
| 15 | 4.1 | ...
|
| Education, recreation and entertainment
| 15 | 6.2 | ...
|
| Miscellaneous goods and services
| 10 | 2.0 | ...
|
| Total
| 186 | 100.0 | ...
|
Household consumption expenditure
Consumption expenditure for the purpose of the index comprises
the goods and services purchased for consumption by the index
population. It excludes income tax, payments to pension funds,
savings, life insurance premiums, house purchases, subscriptions
to trade unions and betting payments.
Method of data collection
Prices are collected by agents in markets, supermarkets, retail
outlets and service establishments. Prices for food items are
ascertained through direct purchase during the first week of each
month. Those for non-durable household goods are obtained during
the third week of each month and those for durable household
goods and services are collected each quarter. The prices used in
the index are the market prices actually paid by households.
Housing
Rent quotations are obtained once a year. During the months
when no rent data are obtained, it is assumed that rents vary in
the same proportion as all other items in the index. The imputed
rent for owner-occupied housing is ascertained.
Specification of varieties
The specifications of items to be priced are given in detail, taking
into account the popularity of the items and the continuity of price
series. Specifications are given in terms of the brand, make, quality
and size.
Substitution, quality change, etc.
If a product is no longer available on the market, another
product is substituted. The base period price of the old product
is adjusted according to the price ratio of the old and the
substitute products. If there is a quality change, the item is
treated as a new one and the same method is used.
Seasonal items
Seasonal fluctuations in item prices are taken into account by using
monthly moving averages.
Computation
The index is computed according to the Laspeyres formula as a
weighted arithmetic average with fixed base, using weights
corresponding to the period 1982-83.
The relatives of average prices for the current and base periods are
used to compute item indices. The average prices are the simple
arithmetic means of all the price quotations obtained.
Other information
Along with the lower-income group index, the Central Bureau of
Statistics publishes middle-income and upper-income group
indices for Nairobi.
Organisation and publication
Ministry of Finance and Planning, Central Bureau of Statistics:
Kenya Statistical Digest
(Nairobi).
Idem: On current and revised Kenyan Consumer Price Indices
.