Namibia Population and Housing Census 2011 - Namibia

Abstract
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The 2011 Population and Housing Census is the third national Census to be conducted in Namibia after independence. The first was conducted 1991 followed by the 2001 Census. Namibia is therefore one of the countries in sub-Saharan Africa that has participated in the 2010 Round of Censuses and followed the international best practice of conducting decennial Censuses, each of which attempts to count and enumerate every person and household in a country every ten years. Surveys, by contrast, collect data from samples of people and/or households.

Censuses provide reliable and critical data on the socio-economic and demographic status of any country. In Namibia, Census data has provided crucial information for development planning and programme implementation. Specifically, the information has assisted in setting benchmarks, formulating policy and the evaluation and monitoring of national development programmes including NDP4, Vision 2030 and several sector programmes. The information has also been used to update the national sampling frame which is used to select samples for household-based surveys, including labour force surveys, demographic and health surveys, household income and expenditure surveys. In addition, Census information will be used to guide the demarcation of Namibia's administrative boundaries where necessary.

At the international level, Census information has been used extensively in monitoring progress towards Namibia's achievement of international targets, particularly the Millennium Development Goals (MDGs).

The latest and most comprehensive Census was conducted in August 2011. Preparations for the Census started in the 2007/2008 financial year under the auspices of the then Central Bureau of Statistics (CBS) which was later transformed into the Namibia Statistics Agency (NSA). The NSA was established under the Statistics Act No. 9 of 2011, with the legal mandate and authority to conduct population Censuses every 10 years. The Census was implemented in three broad phases; pre-enumeration, enumeration and post enumeration.

During the first pre-enumeration phase, activities accomplished including the preparation of a project document, establishing Census management and technical committees, and establishing the Census cartography unit which demarcated the Enumeration Areas (EAs). Other activities included the development of Census instruments and tools, such as the questionnaires, manuals and field control forms.

Field staff were recruited, trained and deployed during the initial stages of the enumeration phase. The actual enumeration exercise was undertaken over a period of about three weeks from 28 August to 15 September 2011, while 28 August 2011 was marked as the reference period or 'Census Day'.

Great efforts were made to check and ensure that the Census data was of high quality to enhance its credibility and increase its usage. Various quality controls were implemented to ensure relevance, timeliness, accuracy, coherence and proper data interpretation. Other activities undertaken to enhance quality included the demarcation of the country into small enumeration areas to ensure comprehensive coverage; the development of structured Census questionnaires after consultat.The post-enumeration phase started with the sending of completed questionnaires to Head Office and the preparation of summaries for the preliminary report, which was published in April 2012. Processing of the Census data began with manual editing and coding, which focused on the household identification section and un-coded parts of the questionnaire. This was followed by the capturing of data through scanning. Finally, the data were verified and errors corrected where necessary. This took longer than planned due to inadequate technical skills.

Geographic coverage
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National coverage

Analysis unit
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Households and persons

Universe
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The sampling universe is defined as all households (private and institutions) from 2011 Census dataset.

Kind of data
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Census/enumeration data [cen]

Sampling procedure
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Sample Design

The stratified random sample was applied on the constituency and urban/rural variables of households list from Namibia 2011 Population and Housing Census for the Public Use Microdata Sample (PUMS) file. The sampling universe is defined as all households (private and institutions) from 2011 Census dataset. Since urban and rural are very important factor in the Namibia situation, it was then decided to take the stratum at the constituency and urban/rural levels. Some constituencies have very lower households in the urban or rural, the office therefore decided for a threshold (low boundary) for sampling within stratum. Based on data analysis, the threshold for stratum of PUMS file is 250 households. Thus, constituency and urban/rural areas with less than 250 households in total were included in the PUMS file. Otherwise, a simple random sampling (SRS) at a 20% sample rate was applied for each stratum. The sampled households include 93,674 housing units and 418,362 people.

Sample Selection

The PUMS sample is selected from households. The PUMS sample of persons in households is selected by keeping all persons in PUMS households. Sample selection process is performed using Census and Survey Processing System (CSPro).

The sample selection program first identifies the 7 census strata with less than 250 households and the households (private and institutions) with more than 50 people. The households in these areas and with this large size are all included in the sample. For the other households, the program randomly generates a number n from 0 to 4. Out of every 5 households, the program selects the nth household to export to the PUMS data file, creating a 20 percent sample of households. Private households and institutions are equally sampled in the PUMS data file.

Note: The 7 census strata with less than 250 households are: Arandis Constituency Rural, Rehoboth East Urban Constituency Rural, Walvis Bay Rural Constituency Rural, Mpungu Constituency Urban, Etayi Constituency Urban, Kalahari Constituency Urban, and Ondobe Constituency Urban.

Mode of data collection
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Face-to-face [f2f]

Research instrument
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The following questionnaire instruments were used for the Namibia 2011 Population and and Housing Census:

Form A (Long Form): For conventional households and residential institutions

Form B1 (Short Form): For special population groups such as persons in transit (travellers), police cells, homeless and off-shore populations

Form B2 (Short Form): For hotels/guesthouses

Form B3 (Short Form): For foreign missions/diplomatic corps

Cleaning operations
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Data editing took place at a number of stages throughout the processing, including:
a) During data collection in the field
b) Manual editing and coding in the office
c) During data entry (Primary validation/editing)
Structure checking and completeness using Structured Query Language (SQL) program
d) Secondary editing:
i. Imputations of variables
ii. Structural checking in Census and Survey Processing System (CSPro) program

Sampling error estimates
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Sampling Error
The standard errors of survey estimates are needed to evaluate the precision of the survey estimation. The statistical software package such as SPSS or SAS can accurately estimate the mean and variance of estimates from the survey. SPSS or SAS software package makes use of the Taylor series approach in computing the variance.

Data appraisal
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Data quality
Great efforts were made to check and ensure that the Census data was of high quality to enhance its credibility and increase its usage. Various quality controls were implemented to ensure relevance, timeliness, accuracy, coherence and proper data interpretation. Other activities undertaken to enhance quality included the demarcation of the country
into small enumeration areas to ensure comprehensive coverage; the development of structured Census questionnaires after consultation with government ministries, university expertise and international partners; the preparation of detailed supervisors' and enumerators' instruction manuals to guide field staff during enumeration; the undertaking of comprehensive publicity and advocacy programmes to ensure full Government support and cooperation from the general public; the testing of questionnaires and other procedures; the provision of adequate training and undertaking of intensive supervision using four supervisory layers; the editing of questionnaires at field level; establishing proper mechanisms which ensured that all completed questionnaires were properly accounted for; ensuring intensive verification, validating all information and error corrections; and developing capacity in data processing with support from the international community.

摘要
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2011年人口与住房普查是纳米比亚独立后进行的第三次全国性普查。第一次普查于1991年进行，随后是2001年的普查。因此，纳米比亚是参与2010年普查轮次并在每十年进行一次普查的国际最佳实践的国家之一，每次普查都旨在每隔十年对国家内的每一个人和每一个家庭进行计数和登记。相比之下，调查通过从人群和/或家庭样本中收集数据。
普查为国家的社会经济和人口状况提供了可靠且关键的数据。在纳米比亚，普查数据为发展规划和项目实施提供了至关重要的信息。具体而言，这些信息有助于设定基准、制定政策以及评估和监控包括NDP4、愿景2030和多个部门项目在内的国家发展计划。这些信息还用于更新国家抽样框架，该框架用于选择家庭调查（包括劳动力调查、人口与健康调查、家庭收入与支出调查）的样本。此外，在必要时，普查信息还将用于指导纳米比亚行政边界的划分。
在国际层面，普查信息被广泛用于监测纳米比亚实现国际目标（尤其是千年发展目标（MDGs））的进展。
最新且最全面的普查于2011年8月进行。普查准备工作始于2007/2008财年，当时由中央统计局（CBS）负责，后来转变为纳米比亚统计局（NSA）。NSA是根据2011年第9号《统计法》设立的，拥有每10年进行人口普查的法律授权和权力。普查分为三个广泛阶段：预登记、登记和后登记。
在第一个预登记阶段，完成的活动包括准备项目文件、建立普查管理和技术委员会，以及建立普查制图单位，该单位划定了登记区域（EAs）。其他活动还包括开发普查工具和手段，如问卷、手册和现场控制表格。
在登记阶段的初始阶段，招募、培训和部署了现场工作人员。实际的登记工作于2011年8月28日至9月15日为期约三周的时间内进行，2011年8月28日被标记为参考期或‘普查日’。
为了确保普查数据的质量，以增强其可信度和提高其使用率，付出了巨大的努力进行检验和确保。实施了各种质量控制措施以确保相关性、及时性、准确性、一致性和适当的数据解释。为了提高质量而采取的其他活动包括将国家划分为小登记区域以确保全面覆盖；在政府各部门、大学专家和国际合作伙伴的咨询后开发结构化的普查问卷；准备详细的监督员和登记员指导手册，以引导现场工作人员在登记期间的工作；开展全面的宣传和倡导活动，以确保政府全面的支持和公众的合作；测试问卷和其他程序；提供充足的培训，并使用四层监督进行密集的监督；在现场层面编辑问卷；建立适当的机制，确保所有完成的问卷都得到妥善记录；确保密集的验证，验证所有信息并进行错误纠正；以及在国际社会的支持下发展数据处理能力。
地理覆盖范围
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全国范围
分析单元
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家庭和人员
总体
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抽样总体定义为2011年普查数据集中的所有家庭（私人机构和机构）。
数据类型
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普查/登记数据 [cen]
抽样程序
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样本设计