Iran, Islamic Rep. of

Title: Household Expenditure and Income Survey, 2003

GENERAL INFORMATION AND BASIC DEFINITIONS

1. Background

Further information is available from Statistical Center of Iran of Office of International Affairs and Public Relations, phone: 98-21 8958189, fax: 98-21 8958189, e-mail: int@sci.or.ir.
Data have been collected by household survey since 1963.

2. Purpose and coverage

The following purposes are considered to be very important or of some importance:

• to obtain weights for consumer price index
• to estimate household expenditure for national accounts
• to study the general structure of household incomes/expenditures
• to study income/expenditure patterns of disadvantaged groups, including pensioner households, single parent households, etc
• to study income/expenditure disparities among socio-economic groups
• to study consumer behaviour among socio-economic groups
• for general poverty and/or income distribution studies
• to study effects on income and expenditure of policy changes, especially tax changes

Lesser importance is attached to:

• for market research purposes

Geographic coverage: National without any specific geographic areas excluded.

Population coverage:
The following types of household are included in the data collection:

• one person private households
• private households with more than one person
• households of other foreigners in the country
• armed forces residing in private housing within military base
• armed forces residing in private housing outside military base

The following types of household are excluded in the data collection:

• those in collective housing (such as long term hospitals, prisons, monasteries, military quarters)
• non-resident households of nationals (households of nationals located abroad)

Units:
Dwelling units are used in the sample selection and are characterised by:

• single structure - detached housing unit

Data are recorded for the household unit which is characterised by:

• one person units
• two or more people living together:
  • sharing a single dwelling or compound
  • sharing meals
  • sharing a common budget for (at least) food and housing expenditures

Data are recorded for the family unit which is characterised by:

• two or more people:
  • living in the same household
  • sharing a single dwelling unit or compound
  • related:
    • by marriage
    • by consensual union
  • sharing a common budget for (at least) food and housing expenditures

Data are recorded for the income unit which is characterised by:

Data are recorded for the consumer unit, expenditure unit or spending unit which is characterised by:

• two or more people:
  • living in the same household
  • sharing a single dwelling or compound
  • sharing meals
  • sharing a common budget for (at least) food and housing expenditures

Unit members: Usual residents temporarily living away from the dwelling are included, if away continuously for less than 12 months. Visitors (not usual residents) temporarily living in the dwelling are not included as unit members. Domestic staff living in same dwelling/compound are included in the unit. Renters living in same dwelling/compound are included in the unit. Boarders living in same dwelling/compound are not included in the unit.

Head of unit:
The concept of head of household/other unit is used in this survey and is characterised by:

• main income earner
• responsible for decisions on main expenditures

3. Reference periods

The time period to which income and/or expenditure statistics refer when released/published is from 04/02 to 04/03. These data are collected in the period from 04/02 to 04/03. This survey is conducted annually. The statistics are published annually.

SURVEY METHODOLOGY

4. Sample design

The Primary, Secondary and Ultimate Sampling Units are enumeration area/district, none and dwelling respectively.

Stratification:
Areas/districts were stratified using the following criteria:

• rural/urban

Households/Consumption Unit, Income Unit, Family Unit were stratified using the following criteria:

• income class
• social class of the head
• income/expenditure deciles

The sampling frames for the Primary Sampling Unit (PSU) and Ultimate Sampling Unit (USU) were the list of Census blocks and the master sample of households respectively. Primary Sampling Units (PSU) were selected using cluster sampling and Ultimate Sampling Units (USU) were selected using systematic sampling.. The overall response rate for the survey was 99 percent. Errors/biases were minimized by using an updated sampling frame, an increased sample size.

Enumeration procedure: Enumeration uses a single round survey design in which each reporting unit is enumerated only once. The sample is not divided into representative sub-samples. If a reporting household/unit drops out from the panel, it is abandonned. No action is taken to select a smaller set of reporting units for more detailed questioning.

DATA COLLECTION, CONCEPTS, DEFINITIONS AND CLASSIFICATIONS

5. Income data

Income data are collected. Income excludes receipts resulting from the sale or reduction of assets and/or from incurring liabilities.

The following receipts are collected separately:

• wages and salaries
• cash bonuses and gratuities
• remuneration for time not worked, e.g. leave pay
• employer social security contributions
• employee social security contributions
• employee income in-kind provided free or subsidized: housing
• employee income in-kind provided free or subsidized: meals
• employee income in-kind provided free or subsidized: car/transportation
• employee income in-kind provided free or subsidized: goods or services produced by employer
• goods produced for own consumption , net of inputs

The following receipts are collected but not separately:

• commissions and tips
• termination and redundancy payments
• profit/loss from unincorporated enterprises (mixed income)
• drawing for own use from unincorporated enterprises
• goods produced for barter , net of inputs
• services from owner-occupied dwellings
• services from other consumer durables (net)
• interest received
• dividends
• rentals (payment received for produced assets e.g. house) , net of expenses
• rents (payment received for un-produced assets e.g. land)
• royalties
• regular pensions/annuities from schemes to which employee does not contribute
• retirement pensions from compulsory social security schemes
• other pensions
• family-related allowances
• sickness benefits
• invalidity benefits
• education-related allowances
• housing allowances
• free government dwelling
• subsidized government dwelling
• medical reimbursements
• other social insurance benefits
• regular support received from non-profit institutions serving households: cash, e.g. scholarships
• regular support received from non-profit institutions serving households: goods and services
• regular support received from non-profit institutions serving households: free dwelling
• regular support received from non-profit institutions serving households: subsidized dwelling
• regular inter-household transfers received from: family, e.g. alimony, child/parental support
• regular inter-household transfers received from: regular cash gifts
• regular inter-household transfers received from: free dwelling
• regular inter-household transfers received from: subsidized dwelling
• social transfers in kind: medical services

The following receipts are classified as income from paid employment:

• wages and salaries
• cash bonuses and gratuities
• commissions and tips
• remuneration for time not worked, e.g. leave pay
• termination and redundancy payments
• employer social security contributions
• employee social security contributions

The following receipts are classified as employment-related transfer income:

• social transfers in kind: medical services

The following receipts are classified as other employment-related income:

• employee income in-kind provided free or subsidized: housing
• employee income in-kind provided free or subsidized: meals
• employee income in-kind provided free or subsidized: car/transportation
• employee income in-kind provided free or subsidized: goods or services produced by employer
• profit/loss from unincorporated enterprises (mixed income)
• drawing for own use from unincorporated enterprises
• goods produced for own consumption , net of inputs
• goods produced for barter , net of inputs)
• services from owner-occupied dwellings
• services from other consumer durables (net)
• interest received
• dividends
• rentals (payment received for produced assets e.g. house) , net of expenses
• rents (payment received for un-produced assets e.g. land)
• royalties
• regular pensions/annuities from schemes to which employee does not contribute
• retirement pensions from compulsory social security schemes
• other pensions
• family-related allowances
• sickness benefits
• invalidity benefits
• education-related allowances
• housing allowances
• free government dwelling
• subsidized government dwelling
• medical reimbursements
• other social insurance benefits
• regular support received from non-profit institutions serving households: cash, e.g. scholarships
• regular support received from non-profit institutions serving households: goods and services
• regular support received from non-profit institutions serving households: free dwelling
• regular support received from non-profit institutions serving households: subsidized dwelling
• regular inter-household transfers received from: family, e.g. alimony, child/parental support
• regular inter-household transfers received from: regular cash gifts
• regular inter-household transfers received from: regular in-kind gifts
• regular inter-household transfers received from: free dwelling
• regular inter-household transfers received from: subsidized dwelling

The following receipts are collected using the last month as the reference period:

• employee income in-kind provided free or subsidized: housing
• employee income in-kind provided free or subsidized: meals
• employee income in-kind provided free or subsidized: car/transportation
• employee income in-kind provided free or subsidized: goods or services produced by employer
• goods produced for own consumption , net of inputs
• goods produced for barter , net of inputs
• services from owner-occupied dwellings
• services from other consumer durables (net)
• interest received
• dividends
• rentals (payment received for produced assets e.g. house) , net of expenses
• rents (payment received for un-produced assets e.g. land)
• royalties
• housing allowances
• free government dwelling
• subsidized government dwelling
• medical reimbursements
• regular support received from non-profit institutions serving households: cash, e.g. scholarships
• regular support received from non-profit institutions serving households: goods and services
• regular support received from non-profit institutions serving households: free dwelling
• regular support received from non-profit institutions serving households: subsidized dwelling
• regular inter-household transfers received from: regular cash gifts
• regular inter-household transfers received from: free dwelling
• regular inter-household transfers received from: subsidized dwelling
• social transfers in kind: medical services

The following receipts are collected using the last 12 months as the reference period:

• wages and salaries
• cash bonuses and gratuities
• commissions and tips
• remuneration for time not worked, e.g. leave pay
• termination and redundancy payments
• employer social security contributions
• employee social security contributions
• profit/loss from unincorporated enterprises (mixed income)
• drawing for own use from unincorporated enterprises
• regular pensions/annuities from schemes to which employee does not contribute
• retirement pensions from compulsory social security schemes
• other pensions
• family-related allowances
• sickness benefits
• invalidity benefits
• education-related allowances
• other social insurance benefits
• regular inter-household transfers received from: family, e.g. alimony, child/parental support

Income data were collected separately for each person receiving income. Components of income for an individual were collected directly from each individual or from one person reporting for all individuals. Negative values (business losses) were included when computing self-employment income.

6. Expenditure data

Data collection method:

Diaries are not used to collect expenditure data.

Interviews are used to collect expenditure data with the respondent completing the interview by a mix of recall and using documentation.

Data for the following expenditure items are collected by referring:¹

• to expenditures in last one month:
  • food
  • other household non-durable goods
  • clothing, footwear
  • other personal non-durable goods
  • housing
  • households services
  • personal services

• to expenditures in last 12 months:
  • other durable goods

Classification: A national classification that is not consistent with COICOP is used for classifying expenditure and has an unspecified number of separate categories at the finest level.

7. Other Data Collection Issues

The following other topics are covered:

• demographic characteristics
• education attainment of members
• employment status of members
• occupation of members
• ownership of selected durable goods
• housing characteristics

Households are not requested to indicate whether durable goods are new or second-hand when their acquisition is recorded.

Non-response: Non-contacted households are substituted, but not refusal households.

DATA PROCESSING, ANALYSIS AND DISSEMINATION

Answers are not pre-coded on data collection forms, but are coded by office staff.

The responses are edited by the following:

• field supervisors
• office staff

Extreme values are amended. In-kind receipts and consumption of own production are included in the estimates. In-kind receipts are valued using: the imputed by field staff using market prices.

Treatment of owner-occupied housing: Values of owner-occupied housing are included in the total income/expenditure estimates and are valued using the current market value.

The following information is used in this valuation:

Treatment of selected groups/values in analysis: Some households/units are excluded from analysis because of incomplete response. Missing values are imputed only on some occasions . Supplementary sources are not used to adjust estimates for under- or over-reporting. Etnic groups are excluded from data analysis.

Weighting:
Weighting factors are used to adjust for:

• sampling
• bench-marking

Sampling errors: Sampling errors are computed for all aggregates and these sampling errors are published.

Tabulation and Analysis: Statistics are presented showing averages per year and statistics are analysed and tabulated for households only.

The following classifications are used for tabulation and analysis of income statistics:

• sex of reference person or head of household
• occupation of reference person or head of household
• other characteristic of reference person or head of household, activity status and literacy
• income percentiles, deciles
• absolute income groups
• principal source of household income
• expenditure percentiles
• expenditure classes in monetary terms
• household size
• structure of household
• other characteristic of household, housing unit

The following classifications are used for tabulation and analysis of expenditure statistics:

• age of reference person or head of household
• sex of reference person or head of household
• occupation of reference person or head of household
• other characteristic of reference person or head of household, activity status and literacy
• income percentiles, deciles
• absolute income groups
• principal source of household income
• expenditure percentiles
• expenditure classes in monetary terms
• household size
• structure of household
• other characteristic of household, housing unit

Documentation and Dissemination:
Published survey reports: urban and rural level of country and provinces

Additional statistics (or special tables on request) are available for public use, free of charge and with charges. Separate tables are published for households with wages/salaries as main source of income. Files of unidentifiable unit data are not available (or available on request) for public use.