Labour Force Survey 2004, March - South Africa

Abstract
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The LFS is a twice-yearly rotating panel household survey, specifically designed to measure the dynamics of employment and unemployment in South Africa. It measures a variety of issues related to the labour market,including unemployment rates (official and expanded), according to standard definitions of the International Labour Organisation (ILO).

All editions of the LFS have been updated (some more than once) since their release. These version changes are detailed in a document available from DataFirst (in the "external documents" section titled "LFS 2000-2008 Collated Version Notes on the South African LFS").

Geographic coverage
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National Coverage

Analysis unit
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Households (dwellings) and individuals

Universe
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The LFS sample covers the non-institutional population except for workers' hostels. However, persons living in private dwelling units within institutions are also enumerated. For example, within a school compound, one would enumerate the schoolmaster's house and teachers' accommodation because these are private dwellings. Students living in a dormitory on the school compound would, however, be excluded.

Kind of data
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Sample survey data [ssd]

Sampling procedure
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The LFS is a twice-yearly rotating panel household survey. A rotating panel sample involves visiting the same dwelling units on a number of occasions (in this instance, five at most), and replacing a proportion of these dwelling units each round. New dwelling units are added to the sample to replace those that are taken out. The pilot round of LFS fieldwork took place in February 2000, based on a probability sample of 10 000 dwelling units. This survey took place six months later, using a larger probability sample of 30,000 dwelling units. Among the 10,000 households visited in February, approximately 40% were re-visited in September 2000. The fieldworkers had some difficulty in identifying certain dwelling units in the sample, particularly in those areas where there are no addresses.

The Master Sample is based on the 1996 Population Census of enumeration areas (EA) and the estimated number of dwelling units from the 1996 Population Census. All 3000 PSUs included in the Master Sample were used in the Labour Force Survey. A PSU is either one EA or several EAs when the number of dwelling units in the base or originally selected EA was found to have less than 100 dwelling units. Each EA had to have approximately 150 dwelling units but it was discovered that many contained less. Thus, in some cases, it has been found necessary to add EAs to the original (census) EA to ensure that the minimum requirement of 100 dwellings, in the first stage of forming the PSUs, was met. The size of the PSUs in the Master Sample varied from 100 to 2445 dwelling units. Special dwellings such as prisons, hospitals, boarding houses, hotels, guest houses (whether catering or self-catering), schools and churches were excluded from the sample.

Explicit stratification of the PSUs was done by province and area type (urban/rural). Within each explicit stratum, the PSUs were implicitly stratified by District Council, Magisterial District and, within the magisterial district, by average household income (for formal urban areas and hostels) or EA. The allocated number of EAs was systematically selected with "probability proportional to size" in each stratum. Once the PSUs included in the sample were known, their boundaries had to be identified on the ground. After boundary identification, the next stage was to list accurately all the dwelling units in the PSUs.

The second stage of the sample selection was to draw from the dwelling units listing whereby a systematic sample of 10 dwelling units was drawn from each PSU. As a result, approximately 30,000 households (units) were interviewed. However, if there was growth of more than 20% in a PSU, then the sample size was increased systematically according to the proportion of growth in the PSU.

A new master sample was drawn in September 2004, benchmarked to Census 2001, for the LFS for the proceeding five years.

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

LFS（劳动力调查）是一项每半年进行一次的轮换面板家庭调查，旨在精确测量南非的就业与失业动态。该调查涵盖了与劳动力市场相关的多种问题，包括根据国际劳工组织（ILO）的标准定义的失业率（官方和扩展定义）。自发布以来，所有版本的LFS均进行了更新（部分版本更新多次），这些版本变更的详细信息可在DataFirst提供的文档中找到，文档标题为“LFS 2000-2008 南非LFS汇总版本注释”。

地理覆盖范围：全国覆盖。
分析单元：家庭（住宅）和个人。
调查范围：LFS样本涵盖了非机构人口，但不包括工人宿舍。然而，居住在机构内私人住宅单位的人员也被纳入统计。例如，在学校园区内，校长住宅和教师宿舍因其为私人住宅而被统计。然而，居住在学校园区宿舍的学生则被排除在外。
数据类型：样本调查数据。
抽样程序：LFS是一项每半年进行一次的轮换面板家庭调查。轮换面板样本涉及在多个场合访问相同的住宅单位（本例中最多五次），并在每一轮中替换一定比例的住宅单位。新住宅单位被添加到样本中，以替换那些被移除的单位。LFS的试点调查于2000年2月进行，基于10,000个住宅单位的概率样本。六个月后进行的调查使用了更大规模的30,000个住宅单位的概率样本。在2月份访问的10,000户家庭中，大约40%在2000年9月被重新访问。调查员在识别某些样本中的住宅单位时遇到了一些困难，尤其是在没有地址的地区。
主样本基于1996年人口普查的普查区和估计的住宅单位数量。主样本中包含的所有3,000个抽样单元（PSU）均用于劳动力调查。PSU可以是单个普查区，也可以是多个普查区，当基础或最初选择的普查区内的住宅单位数量少于100个时。每个普查区必须大约有150个住宅单位，但发现许多普查区包含的住宅单位数量较少。因此，在某些情况下，发现有必要添加普查区到原始（普查）普查区，以确保在形成PSU的第一阶段满足至少100个住宅单位的最小要求。主样本中PSU的大小从100到2,445个住宅单位不等。特殊的住宅单位，如监狱、医院、寄宿学校、酒店、招待所（无论是否提供餐饮服务）以及学校和教堂均被排除在样本之外。
对PSU进行了明确的分层，按省份和区域类型（城市/乡村）进行。在每个明确的层内，PSU被隐式分层，按区议会、司法管辖区进行，在司法管辖区内部，按平均家庭收入（适用于正式城市地区和宿舍）或普查区进行。在每个层内，按“规模成比例的概率”系统地选择了分配的普查区数量。一旦确定了样本中的PSU，就必须在地面上识别它们的边界。在边界识别之后，下一阶段是准确列出PSU中的所有住宅单位。
样本选择的第二阶段是从住宅单位列表中抽取样本，每个PSU从每个PSU中抽取10个住宅单位的系统样本。因此，大约有30,000户家庭（单位）接受了访谈。然而，如果PSU的增长超过20%，则根据PSU增长的比例系统地增加样本量。
2004年9月抽取了一个新的主样本，用于LFS未来五年的调查，并以2001年人口普查为基准。
数据收集方式：面对面。