Quarterly Labour Force Survey 2018, Quarter 2 - South Africa

Abstract
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The Quarterly Labour Force Survey (QLFS) is a household-based sample survey conducted by Statistics South Africa (Stats SA). It collects data on the labour market activities of individuals aged 15 years or older who live in South Africa.

Geographic coverage
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National coverage

Analysis unit
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Individuals

Universe
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The QLFS sample covers the non-institutional population of South Africa with one exception. The only institutional subpopulation included in the QLFS sample are individuals in worker's hostels. 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 Quarterly Labour Force Survey (QLFS) uses a master sample frame which has been developed as a general-purpose household survey frame that can be used by all other Stats SA household surveys that have reasonably compatible design requirement as the QLFS. The 2013 master sample is based on information collected during the 2011 population Census conducted by Stats SA. In preparation for Census 2011, the country was divided into 103 576 enumeration areas (EAs). The census EAs, together with the auxiliary information for the EAs were used as the frame units or building blocks for the formation of primary sampling units (PSUs) for the master sample since they covered the entire country and had other information that is crucial for stratification and creation of PSUs. There are 3 324 primary sampling units (PSUs) in the master sample with an expected sample of approximately 33 000 dwelling units (DUs). The number of PSUs in the current master sample (3 324) reflects an 8,0% increase in the size of the master sample compared to the previous (2007) master sample (which had 3 080 PSUs). The larger master sample of PSUs was selected to improve the precision (smaller CVs) of the QLFS estimates.

The master sample is designed to be representative at provincial level and within provinces at metro/non-metro levels. Within the metros, the sample is further distributed by geographical type. The three geography types are:urban, tribal and farms. This implies, for example, that within a metropolitan area, the sample is representative of the different geography types that may exist within that metro. It is divided equally into four sub-groups or panels called rotation groups. The rotation groups are designed in such a way that each of these groups has the same distribution pattern as that which is observed in the whole sample. They are numbered from one (1) to four (4) and these numbers also correspond to the quarters of the year in which the sample will be rotated for the particular group.

There are a number of aspects in which the 2013 version of the master sample differs from the 2007 version. In particular, the number of primary sample units increased. Mining strata were also introduced which serves to improve the efficiency of estimates relating to employment in mining. The number of geo-types was reduced from 4 to 3 while the new master sample allows for the publication of estimates of the labour market at metro level. The master sample was also adjusted Given the change in the provincial distribution of the South African population between 2001 and 2011. There was also an 8% increase in the sample size of the master sample of PSUs to improve the precision of the QLFS estimates. The sample size increased most notable in Gauteng, the Eastern Cape and KwaZulu-Natal. For more details on the differences between the two master samples please consult the section 8 (technical notes) of the QLFS 2015 Q3 release document (P0211).

From the master sample frame, the QLFS takes draws exmploying a stratified two-stage design with probability proportional to size (PPS) sampling of PSUs in the first stage, and sampling of dwelling units (DUs) with systematic sampling in the second stage. The primary stratification occurred at provincial, metro/non-metro, mining and geography type while the secondary strata were created within the primary strata based on the demographic and socio-economic characteristics of the population.

For each quarter of the QLFS, a ¼ of the sampled dwellings is rotated out of the sample. These dwellings are replaced by new dwellings from the same PSU or the next PSU on the list. Thus, sampled dwellings are expected to remain in the sample for four consecutive quarters. It should be noted that the sampling unit is the dwelling, and the unit of observation is the household. Therefore, if a household moves out of a dwelling after being in the sample for, two quarters and a new household moves in, the new household will be enumerated for the next two quarters. If no household moves into the sampled dwelling, the dwelling will be classified as vacant (or unoccupied).

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

摘要
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本季度劳动力调查（季度劳动力调查，QLFS）是由南非统计局（Stats SA）进行的一项基于家庭的抽样调查。该调查收集了居住在南非且年龄在15岁或以上个人的劳动力市场活动数据。
地理覆盖范围
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全国覆盖
分析单位
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个人
总体
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QLFS样本涵盖了南非的非机构人口，唯一例外的是，QLFS样本中包含的仅限于工人宿舍中的个人。同时，居住在机构内的私人住宅单元也被纳入统计。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在内，而居住在学校园区宿舍的学生则被排除在外。
数据类型
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样本调查数据 [ssd]
抽样程序
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季度劳动力调查（QLFS）采用一个主样本框架，该框架作为一项通用家庭调查框架被开发，可用于所有其他与QLFS具有合理兼容设计要求的Stats SA家庭调查。2013年的主样本基于Stats SA在2011年进行的人口普查收集的信息。为了准备2011年的人口普查，国家被划分为103,576个统计区域（EA）。普查统计区域及其辅助信息被用作主样本一级抽样单位（PSU）形成的基础单元或构建块，因为它们覆盖了整个国家，并包含对分层和创建PSU至关重要的其他信息。主样本中有3,324个一级抽样单位（PSU），预计样本量约为33,000个住宅单位（DU）。当前主样本中PSU的数量（3,324）比上一个（2007年）主样本（3,080个PSU）增长了8.0%。选择更大的主样本PSU是为了提高QLFS估计的精确度（较小的CVs）。
主样本旨在在省级层面以及省内的城市/非城市层面上具有代表性。在城市内部，样本按地理类型进一步分配。三种地理类型是：城市、部落和农场。这意味着，例如，在一个城市区域内，样本代表了该城市可能存在的不同地理类型。它被平等地划分为四个子组或面板，称为轮换组。轮换组的设计方式使得每个组都具有与整个样本相同的分布模式。它们被编号为从一（1）到四（4），这些数字也对应于样本将进行轮换的特定组的季度。
2013版主样本与2007版主样本在多个方面存在差异。特别是，一级样本单位数量增加。还引入了采矿层，这有助于提高与采矿就业相关的估计效率。地理类型从4个减少到3个，而新的主样本允许发布城市层面的劳动力市场估计。鉴于2001年至2011年间南非人口在省级分布上的变化，主样本也进行了调整。主样本PSU的样本量也增加了8%，以提高QLFS估计的精确度。样本量在豪登省、东开普省和夸祖鲁-纳塔尔省增加最为显著。有关两个主样本之间差异的更多详细信息，请参阅QLFS 2015 Q3发布文件（P0211）的第8节（技术说明）。
从主样本框架中，QLFS采用分层两阶段设计，第一阶段采用与规模成比例的概率（PPS）抽样PSU，第二阶段采用系统抽样抽样住宅单位（DU）。一级分层发生在省级、城市/非城市、采矿和地理类型上，而二级分层则基于人口统计和社会经济特征在一级分层内创建。
对于每个QLFS季度，样本中的1/4住宅单位将轮换退出。这些住宅单位将由来自同一PSU或列表中下一个PSU的新住宅单位所取代。因此，样本住宅单位预计将在四个连续季度内保持样本状态。应注意的是，抽样单位是住宅，观测单位是家庭。因此，如果一个家庭在样本中居住了两个季度后搬离住宅，而一个新的家庭搬入，则新家庭将在接下来的两个季度内被统计。如果没有新的家庭搬入样本住宅，则该住宅将被归类为空置（或未被占用）。
数据收集方式
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面对面 [f2f]