General Household Survey-2007 - Nigeria

Abstract
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The Geneal Household Survey is a brainchild of the National Bureau of Statistics (NBS) and is often referred to as Regular survey carried out on quarterly basis by the NBS over the years. In recent times, starting from 2004 to be precise, there is a collaborative effort between the NBS and the CBN in 2004 and 2005 and in 2006 the collaboration incorporated Nigerian Communications commission (NCC).

The main reason of for conducting the survey was to enable the collaborating agencies fulfil their mandate in the production of current and credible statistics, to monitor and evaluate the status of the economy and the various government programmes such as the National Economic Empowerment and Development Strategy (NEEDS) and the Millennium Development Goals (MDGs).

The collaborative survey also assured the elimination of conflicts in data generated by the different agencies and ensured a reliable, authentic national statistics for the country.

Geographic coverage
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National Zone State Local Government

Analysis unit
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Household analysis

Universe
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Household

Kind of data
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Sample survey data [ssd]

Sampling procedure
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The GHS was implemented as a NISH module. Six replicates were studied per state including the FCT, Abuja. With a fixed-take of 10 HUs systematically selected per EA, 600 HUs thus were selected for interview per state including the FCT, Abuja. Hence, nationally, a total of 22,200 HUs were drawn from the 2,220 EAs selected for interview for the GHS. The selected EAs (and hence the HUs) cut across the rural and urban sectors.

The General Household Survey and the National Agricultural Sample Survey designs derived from NBS 2007/12 NISH sample design. The 2007/12 NISH sample design is a 2-stage, replicated and rotated cluster sample design with Enumeration Areas (EAs) as first stage sampling units or Primary Sampling Units (PSUs) while Housing Units constituted the second stage units (secondary sampling units). The housing units were the Ultimate Sampling Units for the multi-subject survey.

First Stage Selection:
Generally, the NISH Master Sample in each state is made up of 200 EAs drawn in 20 replicates. A replicate consists of 10 EAs. Replicates 4 - 9, subsets of the Master Sample were studied for modules of the NISH. Sixty EAs were selected with equal probability from the list of EAs in each state of the federation and FCT, Abuja.

Second Stage Selection:
In each selected EA, a listing of housing units was carried out. The result provided the frame for the second stage selection. Ten housing units were selected systematically in each EA after the completion of the listing exercise. Thereafter, all the households within the selected HUs were interviewed using GHS questionnaire.

At EAs level ,out of the expected 2,220 EAs 2,204 were covered. (by the table on page 177 of the report) and
TABLE 1.6 RETRIEVAL STATUS OF GHS RECORDS

At housing units level, out of the 22,200 expected to be covered, 21,796 were canvassed. (same as above)

AS PER DATA SET
At EAs level ,out of the expected 2,220 EAs 2,204 were covered.
At housing units level, out of the 22,200 expected to be covered, 18,355 were canvassed.

Sampling deviation
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Variance Estimate (Jackknife Method)
Estimating variances using the Jackknife method will require forming replicate from the full sample by randomly eliminating one sample cluster [Enumeration Area (EA) at a time from a state containing k EAs, k replicated estimates are formed by eliminating one of these, at a time, and increasing the weight of the remaining (k-1) EAs by a factor of k/(k-1). This process is repeated for each EA.

For a given state or reporting domain, the estimate of the variance of a rate, r, is given by
k
Var(r ) = (Se)2 = 1 S (ri - r)2
k(k-1) i=1

where (Se) is the standard error,
k is the number of EAs in the state or reporting domain.

r is the weighted estimate calculated from the entire sample of EAs in the state or reporting domain.
ri = kr - (k - 1)r(i), where

r(i) is the re-weighted estimate calculated from the reduced sample of k-1 EAs.

To obtain an estimate of the variance at a higher level, say, at the national level, the process is repeated over all states, with k redefined to refer to the total number of EAs (as opposed to the number in the states).

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

Research instrument
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The questionnaire for the GHS is a structured questionnaire based on household characteristics with some modifications and additions. The House project module is a new addition and some new questions on ICT.

The questionnaires were scaned.

This section were divided into eleven parts.

Part A: Identification code, Response status, Housing characteristics/amenities and Information communication Technology (ICT).
Part B: Socio-demographic characteristics and Labour force characteristics
Part C: Information about the people in the household who were absent during the period of the survey.
Part D: Female contraceptive only, and children ever born by mothers aged 15 years and above
Part E: Births of children in the last 12 months, and trained birth attendant used during child delivery.
Part F: Immunization of children aged 1 year or less and records of their vaccination
Part G: Child nutrition, exclusive breast feeding and length of breast feeding.
Part H: Deaths in the last 12 months, and causes of such deaths.
Part I: Health of all members, of the household and health care providers.
Part J: Household enterprises, income and profit made from such activities.
Part K: Household expenditure, such as school fees, medical expenses, housing expenses, remittance, cloth expenses, transport expenses and food expenses.

Cleaning operations
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The data editing is in 2 phases namely manual editing before the questionnaires were scanned.
This involved using editors at the various zones to manually edit and ensure consistency in the information on the questionnaire.

The second editing is the computer editing, this is the cleaning of the already scanned data by the subject mater group.
The questionnaires were processed at the zones. On completion, computer editing was also carried out to ensure the integrity of the data. .

Response rate
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At National basis, 99.3 percent response rate was acheived at EA level .

While 82.7 percent was acheived at housing units level.

Sampling error estimates
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No sampling error estimate

Data appraisal
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The Quality Control measures were carried out during the survey, essentially to ensure quality of data. There were three levels of supervision involving the supervisors at the first level, CBN staff, NBS State Officers and Zonal Controllers at second level and finally the NBS/NCC Headquarters staff constituting the third level supervision.

摘要
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国家综合家庭调查（Geneal Household Survey）源于国家统计局（NBS），多年来通常被称为国家统计局定期进行的季度调查。自2004年起，尤其是从2004年开始，国家统计局与中央银行（CBN）在2004年和2005年进行了合作，并在2006年将合作扩展至尼日利亚通讯委员会（NCC）。

进行此次调查的主要目的是为了使合作机构能够履行其职责，生产最新和可靠的统计数据，监测和评估经济状况以及各种政府计划，如国家经济赋权与发展战略（NEEDS）和千年发展目标（MDGs）。

合作调查还确保了不同机构生成数据的冲突得以消除，并为国家提供了可靠、真实的国家统计数据。

地理覆盖范围
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全国区域、州、地方政府

分析单元
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家庭分析

总体
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家庭

数据类型
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样本调查数据 [ssd]

抽样程序
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国家综合家庭调查（GHS）作为NISH模块实施。每个州包括联邦首都特区阿布贾在内，研究了六个复制品。在每个地区行政单位（EA）中系统选择10个固定样本单位（HUs），因此每个州包括联邦首都特区阿布贾在内，共选择了600个HUs进行访谈。因此，在全国范围内，从为GHS选择的2,220个EA中抽取了22,200个HUs。

国家综合家庭调查和国家农业样本调查的设计源于国家统计局2007/12 NISH样本设计。2007/12 NISH样本设计是一个两阶段、复制的旋转集群样本设计，地区行政单位（EA）作为第一阶段抽样单位或主要抽样单位（PSU），而住房单位构成了第二阶段单位（次级抽样单位）。住房单位是多主题调查的终极抽样单位。

第一阶段选择：
通常，每个州的NISH主样本由200个EA组成，分为20个复制品。一个复制品由10个EA组成。复制品4-9是主样本的子集，用于研究NISH的各个模块。从联盟各州和联邦首都特区阿布贾的EA列表中，以等概率选择了60个EA。

第二阶段选择：
在每个选定的EA中，对住房单位进行了编目。结果为第二阶段选择提供了框架。在编目工作完成后，在每个EA中系统选择了10个住房单位。然后，使用GHS问卷对所选HUs中的所有家庭进行了访谈。

在EA层面，报告中的第177页表格显示，在预期的2,220个EA中，有2,204个被覆盖。

在住房单位层面，在预期的22,200个中，有21,796个被调查。

按照数据集
在EA层面，在预期的2,220个EA中，有2,204个被覆盖。
在住房单位层面，在预期的22,200个中，有18,355个被调查。

抽样偏差
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方差估计（Jackknife方法）
使用Jackknife方法估计方差需要通过随机消除一个样本集群（一次从一个包含k个EA的州中消除地区行政单位（EA））来形成复制品。通过每次消除这些中的一个，并按因子k/(k-1)增加剩余的（k-1）EA的权重，形成k个复制品。对于每个EA重复此过程。

对于给定的州或报告领域，速率r的方差估计为
k
Var(r ) = (Se)2 = 1 S (ri - r)2
k(k-1) i=1

其中(Se)是标准误差，
k是州或报告领域中EA的数量。

r是从州或报告领域中所有EA的整个样本中计算出的加权估计值。
ri = kr - (k - 1)r(i)，其中

r(i)是从减少到k-1个EA的样本中计算出的重新加权估计值。

为了获得更高层次（例如，国家级）的方差估计，需要对所有州重复此过程，并将k重新定义为EA的总数（而不是州中的数量）。

数据收集方式
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面对面 [f2f]

研究工具
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GHS的问卷是基于家庭特征的标准化问卷，并进行了一些修改和补充。房屋项目模块是新增加的部分，以及一些关于信息通信技术（ICT）的新问题。

问卷被扫描。

本部分分为十一部分。

部分A： 识别码、响应状态、住房特征/设施和信息通信技术（ICT）。
部分B： 社会人口特征和劳动力特征
部分C： 在调查期间缺席的家庭成员信息。
部分D： 仅女性避孕药具，以及15岁及以上母亲所生的孩子
部分E： 过去12个月内出生的孩子，以及儿童出生时的助产士。
部分F： 1岁或以下儿童的免疫接种及其疫苗接种记录
部分G： 儿童营养、纯母乳喂养和母乳喂养的持续时间。
部分H： 过去12个月内的死亡情况，以及死亡原因。
部分I： 家庭成员和医疗保健提供者的健康状况。
部分J： 家庭企业、收入和从事此类活动获得的利润。
部分K： 家庭支出，如学费、医疗费用、住房费用、汇款、服装费用、交通费用和食品费用。

数据清洗操作
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数据编辑分为两个阶段，即问卷扫描之前的手动编辑。
这涉及到使用各区域的编辑器手动编辑，以确保问卷上信息的一致性。

第二个编辑是计算机编辑，这是主题小组对已扫描数据的清洗。

问卷在区域进行处理。完成后，也进行了计算机编辑，以确保数据的完整性。

响应率
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在全国范围内，EA层面达到了99.3%的响应率。

而在住房单位层面，达到了82.7%的响应率。

抽样误差估计
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没有抽样误差估计

数据评估
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在调查期间进行了质量控制措施，主要是为了确保数据质量。涉及三个层面的监督，包括第一层面的监督员、中央银行工作人员、国家统计局州官员和区域控制员，第二层面的监督员，以及最终的国家统计局/尼日利亚通讯委员会总部工作人员构成的第三层面监督。