Project for Statistics on Living Standards and Development 1993 - South Africa

Abstract
---------------------------

The Project for Statistics on Living standards and Development was a countrywide World Bank Living Standards Measurement Survey. It covered approximately 9000 households, drawn from a representative sample of South African households. The fieldwork was undertaken during the nine months leading up to the country's first democratic elections at the end of April 1994. The purpose of the survey was to collect statistical information about the conditions under which South Africans live in order to provide policymakers with the data necessary for planning strategies. This data would aid the implementation of goals such as those outlined in the Government of National Unity's Reconstruction and Development Programme.

Geographic coverage
---------------------------

National

Analysis unit
---------------------------

Households

Universe
---------------------------

All Household members. Individuals in hospitals, old age homes, hotels and hostels of educational institutions were not included in the sample. Migrant labour hostels were included. In addition to those that turned up in the selected ESDs, a sample of three hostels was chosen from a national list provided by the Human Sciences Research Council and within each of these hostels a representative sample was drawn on a similar basis as described above for the households in ESDs.

Kind of data
---------------------------

Sample survey data [ssd]

Sampling procedure
---------------------------

(a) SAMPLING DESIGN

Sample size is 9,000 households. The sample design adopted for the study was a two-stage self-weighting design in which the first stage units were Census Enumerator Subdistricts (ESDs, or their equivalent) and the second stage were households. The advantage of using such a design is that it provides a representative sample that need not be based on accurate census population distribution in the case of South Africa, the sample will automatically include many poor people, without the need to go beyond this and oversample the poor. Proportionate sampling as in such a self-weighting sample design offers the simplest possible data files for further analysis, as weights do not have to be added. However, in the end this advantage could not be retained, and weights had to be added.

(b) SAMPLE FRAME

The sampling frame was drawn up on the basis of small, clearly demarcated area units, each with a population estimate. The nature of the self-weighting procedure adopted ensured that this population estimate was not important for determining the final sample, however. For most of the country, census ESDs were used. Where some ESDs comprised relatively large populations as for instance in some black townships such as Soweto, aerial photographs were used to divide the areas into blocks of approximately equal population size. In other instances, particularly in some of the former homelands, the area units were not ESDs but villages or village groups. In the sample design chosen, the area stage units (generally ESDs) were selected with probability proportional to size, based on the census population. Systematic sampling was used throughout that is, sampling at fixed interval in a list of ESDs, starting at a randomly selected starting point. Given that sampling was self-weighting, the impact of stratification was expected to be modest. The main objective was to ensure that the racial and geographic breakdown approximated the national population distribution. This was done by listing the area stage units (ESDs) by statistical region and then within the statistical region by urban or rural. Within these sub-statistical regions, the ESDs were then listed in order of percentage African. The sampling interval for the selection of the ESDs was obtained by dividing the 1991 census population of 38,120,853 by the 300 clusters to be selected. This yielded 105,800. Starting at a randomly selected point, every 105,800th person down the cluster list was selected. This ensured both geographic and racial diversity (ESDs were ordered by statistical sub-region and proportion of the population African). In three or four instances, the ESD chosen was judged inaccessible and replaced with a similar one. In the second sampling stage the unit of analysis was the household. In each selected ESD a listing or enumeration of households was carried out by means of a field operation. From the households listed in an ESD a sample of households was selected by systematic sampling. Even though the ultimate enumeration unit was the household, in most cases "stands" were used as enumeration units. However, when a stand was chosen as the enumeration unit all households on that stand had to be interviewed.

Mode of data collection
---------------------------

Face-to-face [f2f]

Cleaning operations
---------------------------

All the questionnaires were checked when received. Where information was incomplete or appeared contradictory, the questionnaire was sent back to the relevant survey organization. As soon as the data was available, it was captured using local development platform ADE. This was completed in February 1994. Following this, a series of exploratory programs were written to highlight inconsistencies and outlier. For example, all person level files were linked together to ensure that the same person code reported in different sections of the questionnaire corresponded to the same person. The error reports from these programs were compared to the questionnaires and the necessary alterations made. This was a lengthy process, as several files were checked more than once, and completed at the beginning of August 1994. In some cases, questionnaires would contain missing values, or comments that the respondent did not know, or refused to answer a question.

These responses are coded in the data files with the following values: VALUE MEANING
-1 : The data was not available on the questionnaire or form
-2 : The field is not applicable
-3 : Respondent refused to answer
-4 : Respondent did not know answer to question

Data appraisal
---------------------------

The data collected in clusters 217 and 218 should be viewed as highly unreliable and therefore removed from the data set. The data currently available on the web site has been revised to remove the data from these clusters. Researchers who have downloaded the data in the past should revise their data sets. For information on the data in those clusters, contact SALDRU http://www.saldru.uct.ac.za/.

摘要
---------------------------
生活水准与发展统计项目系由世界银行开展的一项全国性生活水准测量调查。该调查覆盖了约9000户家庭，这些家庭源自南非家庭的代表性样本。实地调研在1994年4月底国家首次民主选举前的九个月内进行。调查的目的是收集有关南非人生活状况的统计数据，以便为政策制定者提供制定策略所需的数据。这些数据将有助于实现国家统一政府重建与发展计划中概述的目标。
地理覆盖范围
---------------------------
全国
分析单位
---------------------------
家庭
总体
---------------------------
所有家庭成员。不包括医院、养老院、教育机构宿舍和旅店中的个体。包括移民劳工宿舍。除了在选定的ESD中出现的情况外，还从人类科学研究中心提供的国家名单中选择三个宿舍的样本，并在每个宿舍中根据上述ESD家庭的方式抽取代表性样本。
数据类型
---------------------------
样本调查数据 [ssd]
抽样程序
---------------------------
(a) 抽样设计
样本量为9000户家庭。本研究采用的抽样设计为两阶段自加权设计，其中第一阶段单位为人口普查枚举子区（ESD或其等效单位），第二阶段为家庭。使用此类设计的优点是它提供了一个代表性样本，无需基于南非准确的普查人口分布，该样本将自动包括许多穷人，无需超出此范围并过度抽样穷人。此类自加权样本设计中的比例抽样提供了最简单的数据文件，以便进一步分析，因为无需添加权重。然而，最终这种优势未能保留，并不得不添加权重。
(b) 样本框
样本框是根据具有人口估计的小型、明确划分的区域单位编制的。采用的自加权程序的性质确保了这种人口估计对于确定最终样本并不重要。对于大多数国家，使用了人口普查ESD。对于一些ESD包含相对较大的人口，例如Soweto等一些黑人小镇，使用了航空照片将区域划分为约相等人口规模的区块。在其他情况下，特别是在一些前保留地，区域单位不是ESD，而是村庄或村庄群。在选定的样本设计中，区域阶段单位（通常是ESD）是根据普查人口按比例选择的，整个过程中使用了系统抽样，即在ESD列表中按固定间隔抽样，从随机选定的起点开始。鉴于抽样是自加权的，预计分层的影响将有限。主要目标是确保种族和地理分布接近国家人口分布。这是通过按统计区域列出区域阶段单位（ESD），然后在统计区域内按城市或农村列出来实现的。在这些次统计区域内，ESD按非洲人口百分比排序。选择ESD的抽样间隔是通过将1991年普查人口38,120,853除以要选择的300个集群得到的。这产生了105,800。从随机选定的点开始，每105,800个人被选中。这确保了地理和种族的多样性（ESD按统计子区域和非洲人口比例排序）。在三个或四个实例中，选定的ESD被认为难以进入，并用类似的ESD替换。在第二阶段抽样中，分析单位是家庭。在每个选定的ESD中，通过实地操作进行家庭名单或枚举。从ESD中列出的家庭中选择样本家庭。尽管最终枚举单位是家庭，但在大多数情况下使用“地块”作为枚举单位。然而，当选择地块作为枚举单位时，该地块上的所有家庭都必须接受访谈。
数据收集方式
---------------------------
面对面 [f2f]
清洗操作
---------------------------
所有问卷收到后都进行了检查。如果信息不完整或似乎存在矛盾，则将问卷退回相关调查组织。一旦数据可用，就使用本地开发平台ADE进行捕获。这于1994年2月完成。此后，编写了一系列探索性程序，以突出不一致和异常值。例如，将所有个人级别文件链接在一起，以确保在不同部分的问卷中报告的同一人代码对应于同一人。将这些程序的错误报告与问卷进行比较，并做出必要的更改。这是一个漫长的过程，因为几个文件被检查多次，并于1994年8月初完成。在某些情况下，问卷可能会包含缺失值，或受访者不知道，或拒绝回答问题的评论。
这些响应在数据文件中以以下值进行编码：值 意义
-1：问卷或表格上没有数据
-2：该字段不适用
-3：受访者拒绝回答
-4：受访者不知道问题的答案
数据评估
---------------------------
应将集群217和218收集的数据视为高度不可靠，因此应从数据集中删除。网站上目前可用的数据已修订，以删除这些集群的数据。过去下载过数据的学者应修订他们的数据集。有关这些集群的数据信息，请联系SALDRU http://www.saldru.uct.ac.za/。