Namibia Household Income and Expenditure Survey 1993-1994
Namibia, 1993 - 1994
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Reference ID
nam-nsa-nhies-1993-1994-v1
Producer(s)
Central Statistics Office
Created on
Nov 16, 2017
Last modified
May 23, 2023
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29721
Identification
Survey ID Number
nam-nsa-nhies-1993-1994-v1
Title
Namibia Household Income and Expenditure Survey 1993-1994
Country
| Name | Country code |
|---|---|
| Namibia | NAM |
Study type
Income/Expenditure Survey [hh/ies]
Abstract
The 1993/94 Namibia Household Income and Expenditure Survey (NHIES) is the first module of the National Household Survey Programme endorsed by the Government in 1993, a follow-up of the 1991 Population and Housing Census and represents one more step in providing useful statistics for charting and assessing the socio-economic development of the Namibian society. This programme is an integrated part of A Five-Year Development Plan of Statistics in Namibia. The purpose of the study is to highlight the living conditions of the Namibian people with the emphasis on the distribution of the economic resources among the Namibian households. The study provides a basic description of the living conditions in Namibia concerning economic activity, housing and infrastructure, possession of capital goods and property, economic standard as well as consumption and expenditure patterns.
Kind of Data
Sample survey data [ssd]
Unit of Analysis
Households and individuals
Version
Version Description
Version 1: Edited, anonymised dataset for public distribution.
Scope
Notes
HOUSEHOLD: Household composition, Geolocality, Dwelling characteristics, Fuel, Plumbing, Drinking water, Tenancy, Rent, Access/distance to facilities/services, Language, Household assets, Access to income generating facilities, Entrepreneurship, Finance, Pension, Income, Expenditure, Remittances
INDIVIDUALS: Demographic characteristics, Educational attainment, Employment market status, Occupation, Industry
INDIVIDUALS: Demographic characteristics, Educational attainment, Employment market status, Occupation, Industry
Coverage
Geographic Coverage
National coverage
Universe
The 1993/94 Namibia Household Income and Expenditure Survey covered all private households in Namibia. Institutional households (like hospitals, hostels, barracks and prisons) are not included in the NHIES.
Producers and sponsors
Primary investigators
| Name | Affiliation |
|---|---|
| Central Statistics Office | National Planning Commision |
Producers
| Name | Role |
|---|---|
| The United Nations Development Programme | Technical Support for Establishment of the CSO |
| Government of Sweden | Technical Support for Establishment of the CSO |
| Government of the United Kingdom | Technical Support for Establishment of the CSO |
Other Identifications/Acknowledgments
| Name | Affiliation |
|---|---|
| Vekondja Tjikuzu | Survey and Cartographic Unit |
| John de Wet | Survey and Cartographic Unit |
| Staffan Wahlström | Survey and Cartographic Unit |
| Alvis Weerasinghe | Survey and Cartographic Unit |
| Ottillie Iiyambo-Mwazi | Data Processing Unit |
| Onno Amutenya | Data Processing Unit |
| Bertil Georgsson/Soe Paing | Data Processing Unit |
| Sammy Kinyanjui | Data Processing Unit |
Sampling
Sampling Procedure
There are essentially two sampling procedures that were followed in the NHIES 1993/94. One for Walvis Bay and one for the rest of Namibia. These will be addressed in turn.
The NHIES 1993/94 for most of Namibia follows a two stage sample design, taking random draws of geographical areas before randomly selecting households within that area. To do this, the Central Statistics Office (CSO), under the National Planning Commission (NPC), had to first develop a master sample frame.
To develop this master sample frame, a set of geographical areas, Primary Sampling Units (PSUs), was created and contained, on average, between 80 and 200 households. These areas were built from the Enumeration Areas (EAs) prepared for the 1991 Population and Housing Census. Small EAs were combined with adjacent EAs to form PSUs of sufficient size. The rule applied was that the number of households in a PSU according to the 1991 Population and Housing Census should be at least 80 households. About 1300 of the 1695 PSUs are made up of single EAs from the 1991 Population and Housing Census while about 400 PSUs are formed by joining two or more EAs. The 1695 PSUs, covering the whole of Namibia (except the Walvis Bay area), were separated into strata of PSUs by region and by rural, small urban and urban areas. The stratification into rural, small urban and urban areas was based on a classification of enumeration areas conducted during the preparations of the 1991 Population and Housing Census. (Note: A different definition of rural and urban areas is used in the statistical reporting from the 1991 Population and Housing Census and the HIES.) The urban areas in the Khomas region and some urban areas in the Otjozondjupa region were further stratified into high income and middle/low income areas. In this way 32 strata were created for the sampling of PSUs As a result of the way the PSUs were created, the number of PSUs of the master sample frame in each region and in each stratum is roughly proportional to the number of households in the region and in the stratum respectively as estimated in the 1991 Population and Housing Census.
Having developed the master sample frame, the NHIES 1993/94 was sampled according to a Probability Proporitional to Size (PPS) of PSUs method in the first stage and a fixed size equal probability sample of households in each selected PSU in the seond. 192 PSUs were selected in the first stage as the master sample.
Initially the master sample was proportionally allocated over the strata in the master sample frame according to the number of households in the 1991 Population and Housing Census. However, some modifications of the allocation were made based on the following:
- The variation between households in income level seems to be generally larger in the urban areas than in the rural areas.
- The survey costs are considerably lower in the urban areas.
- There should be at least 10 PSUs sampled from each region to allow for reasonably good statistics from each region.
It was deemed necessary to have a slight oversampling in urban areas and in one region (Omaheke). A proportional allocation of the 192 PSUs over urban/rural areas gave 66 urban and 126 rural PSUs. But, given the above specifications, the selection of the master sample resulted into 81 urban and 111 rural PSUs.
In the second stage, households were selected from the chosen PSUs. A list of households for each PSU was prepared during a separate listing exercise. The listing was carried out as closely as possible to the start of the data collection in a certain PSU i.e. the month before the NHIES survey month of the PSU. The list of households in the PSU was used as the sampling frame for the selection of households and a systematic equal probability random sample of 24 households from each PSU was drawn.
As initially mentioned, sampling was done slightly differently in Walvis Bay. This is because the region was not integrated in Namibia until 1 March 1994 and could therefore not be included in the NHIES before that date. For planning and logistic reasons Walvis Bay was included in the survey somewhat later - from May 1994. This means that Walvis Bay was included in the NHIES during the last six months of the survey year. The sampling procedure was different from the rest of Namibia. In Walvis Bay the municipality authorities have for administrative purposes created computerized registers of the households in all the three main town areas - Central Walvis Bay (incl. Langstrand), Kuisebmund and Narraville. Most of the households in Walvis Bay are covered by these registers. There are some areas, however, which are not covered by the administrative registers. These areas are the hostel areas of Walvis Bay and the area along the Kuiseb river where the Topnaar population lives. To cover also these population groups, CSO conducted listing of the households in these areas. For security reasons all the hostel areas could not be listed but some areas had to be excluded from the HIES. The number of listed households in the hostel areas was 99 and probably about the same number of households was not listed. The number of Topnaar households listed was 73.
Altogether 144 households from Walvis Bay were selected by mainly a stratified one-stage sample design to be included in the NHIES sample. 24 households were sampled during each of the six months (6 * 24 = 144). Separate strata were defined for Central Walvis Bay (incl. Langstrand), Kuisebmund (excl. the hostel areas), Narraville, the hostel areas and the Topnaar population and altogether 36, 54, 36, 6 and 12 households respectively were sampled from each stratum. (During May-July 1994 10 households were selected each month in Kuisebmund excluding the hostel areas. During August-October 1994 only 8 households were selected in Kuisebmund excluding the hostel areas while 2 households were selected in the hostel areas.)
The NHIES 1993/94 for most of Namibia follows a two stage sample design, taking random draws of geographical areas before randomly selecting households within that area. To do this, the Central Statistics Office (CSO), under the National Planning Commission (NPC), had to first develop a master sample frame.
To develop this master sample frame, a set of geographical areas, Primary Sampling Units (PSUs), was created and contained, on average, between 80 and 200 households. These areas were built from the Enumeration Areas (EAs) prepared for the 1991 Population and Housing Census. Small EAs were combined with adjacent EAs to form PSUs of sufficient size. The rule applied was that the number of households in a PSU according to the 1991 Population and Housing Census should be at least 80 households. About 1300 of the 1695 PSUs are made up of single EAs from the 1991 Population and Housing Census while about 400 PSUs are formed by joining two or more EAs. The 1695 PSUs, covering the whole of Namibia (except the Walvis Bay area), were separated into strata of PSUs by region and by rural, small urban and urban areas. The stratification into rural, small urban and urban areas was based on a classification of enumeration areas conducted during the preparations of the 1991 Population and Housing Census. (Note: A different definition of rural and urban areas is used in the statistical reporting from the 1991 Population and Housing Census and the HIES.) The urban areas in the Khomas region and some urban areas in the Otjozondjupa region were further stratified into high income and middle/low income areas. In this way 32 strata were created for the sampling of PSUs As a result of the way the PSUs were created, the number of PSUs of the master sample frame in each region and in each stratum is roughly proportional to the number of households in the region and in the stratum respectively as estimated in the 1991 Population and Housing Census.
Having developed the master sample frame, the NHIES 1993/94 was sampled according to a Probability Proporitional to Size (PPS) of PSUs method in the first stage and a fixed size equal probability sample of households in each selected PSU in the seond. 192 PSUs were selected in the first stage as the master sample.
Initially the master sample was proportionally allocated over the strata in the master sample frame according to the number of households in the 1991 Population and Housing Census. However, some modifications of the allocation were made based on the following:
- The variation between households in income level seems to be generally larger in the urban areas than in the rural areas.
- The survey costs are considerably lower in the urban areas.
- There should be at least 10 PSUs sampled from each region to allow for reasonably good statistics from each region.
It was deemed necessary to have a slight oversampling in urban areas and in one region (Omaheke). A proportional allocation of the 192 PSUs over urban/rural areas gave 66 urban and 126 rural PSUs. But, given the above specifications, the selection of the master sample resulted into 81 urban and 111 rural PSUs.
In the second stage, households were selected from the chosen PSUs. A list of households for each PSU was prepared during a separate listing exercise. The listing was carried out as closely as possible to the start of the data collection in a certain PSU i.e. the month before the NHIES survey month of the PSU. The list of households in the PSU was used as the sampling frame for the selection of households and a systematic equal probability random sample of 24 households from each PSU was drawn.
As initially mentioned, sampling was done slightly differently in Walvis Bay. This is because the region was not integrated in Namibia until 1 March 1994 and could therefore not be included in the NHIES before that date. For planning and logistic reasons Walvis Bay was included in the survey somewhat later - from May 1994. This means that Walvis Bay was included in the NHIES during the last six months of the survey year. The sampling procedure was different from the rest of Namibia. In Walvis Bay the municipality authorities have for administrative purposes created computerized registers of the households in all the three main town areas - Central Walvis Bay (incl. Langstrand), Kuisebmund and Narraville. Most of the households in Walvis Bay are covered by these registers. There are some areas, however, which are not covered by the administrative registers. These areas are the hostel areas of Walvis Bay and the area along the Kuiseb river where the Topnaar population lives. To cover also these population groups, CSO conducted listing of the households in these areas. For security reasons all the hostel areas could not be listed but some areas had to be excluded from the HIES. The number of listed households in the hostel areas was 99 and probably about the same number of households was not listed. The number of Topnaar households listed was 73.
Altogether 144 households from Walvis Bay were selected by mainly a stratified one-stage sample design to be included in the NHIES sample. 24 households were sampled during each of the six months (6 * 24 = 144). Separate strata were defined for Central Walvis Bay (incl. Langstrand), Kuisebmund (excl. the hostel areas), Narraville, the hostel areas and the Topnaar population and altogether 36, 54, 36, 6 and 12 households respectively were sampled from each stratum. (During May-July 1994 10 households were selected each month in Kuisebmund excluding the hostel areas. During August-October 1994 only 8 households were selected in Kuisebmund excluding the hostel areas while 2 households were selected in the hostel areas.)
Deviations from the Sample Design
There were numerous issues related to coverage and data collection. These are extensively documented in Section 9 of the Technical and Administrative Report.
Response Rate
The overall response rate for the 1993/1994 NHIES was 92.5 percent.
Weighting
The weighting variable included in the NHIES is inverse to the inclusion probability for each sample. The weighting variable varies between a minimum of roughly 6.08 and a maximum of 245.3. For more detailed on weighting users are encouraged to consult the 1993/1994 Namibia Household Income and Expenditure Survey Administrative and Technical Report. Section 5.3 contains a lot of information on the weighting procedure. Please not that in the household datafile the weighting variable is called "rf". Additionally, there are the variables "rf1" and "rf4" which are alternative weights as explained in the Administrative and Technical Report
Data Collection
Dates of Data Collection
| Start | End |
|---|---|
| 1993-11-01 | 1994-10-01 |
Data Collection Mode
Face-to-face [f2f]
Data Collection Notes
The first planning period was between March 1992 and March 1993. During this period four short-term missions from Statistics Sweden took place. Basic proposals for the NHIES design were developed including sample design, questionnaires and manuals. The developing of a sample design for the NHIES also included the developing of a proposal for a Namibian master sample. From February 1993 a long-term survey advisor from Statistics Sweden was connected to CSO. UNDP provided a UN volunteer for the survey work already from 1992. The building up of a Survey and Cartographic Unit at CSO started during this period. Between April and June 1993 the CSO began to conduct a pilot study. This pilot study was evaluated between July and August 1993. 12 temporary staff members were recruited for the duration of the pilot study as interviewers.
The actual NHIES survey period was the twelve months period from November 1993 and October 1994. The preparations started already in September/October 1993 by training field staff (9 field supervisors and 55 interviewers) and the listing of all households in selected geographical areas (primary sampling units) for the first survey month - November 1993. Listing of households in selected geographical areas, sampling of households for the NHIES and data collection went on from October 1993 to November 1994. The data collection was finalized during the first two weeks of November 1994.
The actual NHIES survey period was the twelve months period from November 1993 and October 1994. The preparations started already in September/October 1993 by training field staff (9 field supervisors and 55 interviewers) and the listing of all households in selected geographical areas (primary sampling units) for the first survey month - November 1993. Listing of households in selected geographical areas, sampling of households for the NHIES and data collection went on from October 1993 to November 1994. The data collection was finalized during the first two weeks of November 1994.
Data Collectors
| Name | Abbreviation | Affiliation |
|---|---|---|
| Central Statistics Office | CSO | National Planning Commission |
Questionnaires
Questionnaires
The contents of the NHIES set of questionnaires were mainly decided on by the statistical user community. The first user-producer meetings took place during March/April 1992 during the first short-term mission of two Swedish consultants. Users from the following institutions took part in these meetings: the National Planning Commission, the Ministry of Finance, the Ministry of Trade and Industry, the Ministry of Labour, the Ministry of Local Government and Housing, the Ministry of Lands, Resettlement and Rehabilitation , the Bank of Namibia, the Namibian Economic Policy Research Unit (NEPRU) and the Social Sciences Division of the University of Namibia. Based on the pilot survey experiences and other considerations, revisions of the NHIES design took place during July - August 1993. Major changes were made in the questionnaires. All of the questionnaires were translated into the major languages of Namibia.
The main forms were:
- FORM I: Particulars on Individuals and Households. Filled in at the first interview visit which normally took place the week before the survey month.
- FORM II: Daily Record Book. Given to the household at the first visit. The Daily Record Book. The household was urged to record all their transactions on a daily basis in the book. If no literate person was available in the household or its proximity, frequent visits had to be paid by the interviewer. The first interview visit was followed by weekly visits to the household for collecting data on transactions.
- FORM III: Cash disbursement and Receipts. Transactions in cash recorded by the household were transferred by the interviewers on a weekly basis. The interviewer also regularly probed the households for cash transactions which they might have forgotten to record in the Daily Record Book.
- FORM IV: Transactions in Kind. The interviewer also probed the households for in kind transactions which they might have forgotten to record in the Daily Record Book.
- FORM V: Household Opinions. Consists of a module about household opinions concerning how to improve the economic well-being of the households. The Form V interview took place at the last interview visit after the survey month when the data collection concerning all other forms was ready.
The main forms were:
- FORM I: Particulars on Individuals and Households. Filled in at the first interview visit which normally took place the week before the survey month.
- FORM II: Daily Record Book. Given to the household at the first visit. The Daily Record Book. The household was urged to record all their transactions on a daily basis in the book. If no literate person was available in the household or its proximity, frequent visits had to be paid by the interviewer. The first interview visit was followed by weekly visits to the household for collecting data on transactions.
- FORM III: Cash disbursement and Receipts. Transactions in cash recorded by the household were transferred by the interviewers on a weekly basis. The interviewer also regularly probed the households for cash transactions which they might have forgotten to record in the Daily Record Book.
- FORM IV: Transactions in Kind. The interviewer also probed the households for in kind transactions which they might have forgotten to record in the Daily Record Book.
- FORM V: Household Opinions. Consists of a module about household opinions concerning how to improve the economic well-being of the households. The Form V interview took place at the last interview visit after the survey month when the data collection concerning all other forms was ready.
Data Processing
Data Editing
Editing, coding and data entry of the data collected in the field was conducted by temporary staff at the Data Processing Unit and the Survey and Cartographic Unit of the CSO Head Office in Windhoek between December 1993 and August 1995. Further
Data Appraisal
Estimates of Sampling Error
Section 9 (particularly 9.5) of the Administrative and Technical Report documents issues related to sampling error in some detail. The interested user is encouraged to to consult this document.
Access policy
Contacts
| Name | Affiliation | URL | |
|---|---|---|---|
| Namibian Statistics Agency | Government of the Republic of Namibia | info@nsa.org.na | Link |
Access conditions
Public use files, available to all
Citation requirements
Namibia Central Statistics Office. Namibia Household Income and Expenditure Survey 1993-1994 [dataset]. Version 1. Namibian Statistics Agency [producer and distributor].
Access authority
| Name | Affiliation | URL | |
|---|---|---|---|
| Namibian Statistics Agency | Government of the Republic of Namibia | info@nsa.org.na | Link |
Metadata production
Producers
| Name | Abbreviation | Affiliation | Role |
|---|---|---|---|
| Namibian Statistics Agency | NSA | Government of the Republic of Namibia | Documentation of the DDI |
Date of Metadata Production
2013-06-20
DDI Document version
Version2