The Quarterly Labour Force Survey (QLFS) is a household-based sample survey conducted by Statistics South Africa (Stats SA). The survey collects data on the labour market activities of individuals aged 15 years and above who live in South Africa. The objective of the QLFS is to collect quarterly information about persons in the labour market, i.e., those who are employed; those who are unemployed and those who are not economically active.
The Quarterly Labour Force Survey (QLFS) frame has been developed as a general-purpose household survey frame that can be used by all other household surveys, irrespective of the sample size requirement of the survey. The sample size for the QLFS is roughly 30,000 dwellings per quarter. The sample is based on information collected during the 2001 Population Census conducted by Stats SA. The sample is designed to be representative at provincial level and within provinces at metro/non-metro level. Within the metros, the sample is further distributed by geography type. The four geography types are: urban formal, urban informal, farms, and tribal. This implies, for example, that within a metropolitan area the sample is representative of the different geography types that may exist within that metro.
Kind of data
Sample survey data [ssd]
v2.0: Edited, anonymised dataset for public distribution
This version of the QLFS 2013 Q2 was downloaded from the Statistics South Africa (Stats SA) website in April 2014 as a revision to the version previously downloaded in September 2013.
The two versions have different weights. Stats SA updated the QLFS results (2008-2013) to reflect the new population benchmarks from Census 2011. Although the weighting changes are not clearly documented by Stats SA, users are advised to remain aware of these slight calibration differences when employing weights.
Unit of analysis
Members of households aged 15 years or older.
The QLFS 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.
Producers and sponsors
Statistics South Africa
The sample size for the QLFS is roughly 30,000 dwellings.The sample is based on information collected during the 2001 Population Census conducted by Statistics South Africa (Stats SA). In preparation for Census 2001, the country was divided into 80,787 enumeration areas (EAs). Some of these EAs are small in terms of the number of households that were enumerated in them at the time of Census 2001. The Stats SA household-based surveys use a Master Sample of primary sampling units (PSUs) which comprises EAs that are drawn from across the country. For the purposes of the Master Sample, the EAs that contained fewer than 25 households were excluded from the sampling frame, and those that contained between 25 and 99 households were combined with other EAs of the same geographic type to form primary sampling units (PSUs). The number of EAs per PSU ranges between one and four. On the other hand, very large EAs represent two or more PSUs.
The sample is designed to be representative at provincial level and within provinces at metro/non-metro level. Within the metros, the sample is further distributed by geography type. The four geography types are: urban formal, urban informal, farms, and tribal. This implies that, for example, within a metropolitan area the sample is designed to be representative at the different geography types that may exist within that metro.
The current sample size is 3,080 PSUs. It is equally divided into four subgroups 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 to four and these numbers also correspond to the quarters of the year in which the sample will be rotated for the particular group.
The sample for the Labour Force Survey is based on a stratified two-stage design with probability proportional to size (PPS) sampling of primary sampling units (PSUs) in the first stage, and sampling of dwelling units (DUs) with systematic sampling in the second stage. The sampled PSUs have been assigned to 4 rotation groups, and dwellings selected from the PSUs assigned to rotation group '1' are rotated in the first quarter. Similarly, the dwellings selected from the PSUs assigned to rotation group '2' are rotated in the second quarter, and so on. Thus, each sampled dwelling will 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, say 2 quarters, and a new household moves in, then 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 (unoccupied). At the end of each quarter, a quarter of the sampled dwellings rotate out of the sample and are replaced by new dwellings from the same PSU or the next PSU on the list. A total of 3 080 PSUs were selected for the redesigned LFS, and 770 have been assigned to each of the four rotation groups.
Below is a list of response rate by province for the period of January-March 2013:
Western Cape: 90.4%
Eastern Cape: 98.7%
Northern Cape: 90.2%
Free State: 97.8%
North West: 93.6%
South Africa: 93.1%
Stats SA updated the QLFS results (2008-2013) to reflect the new population benchmarks from Census 2011. Although the weighting changes are not clearly documented by Stats SA, users are advised to remain aware of these slight calibration differences between the previous version and the current (revised) data version when employing weights.
The sampling weights for the data collected from the sampled households are constructed so that the responses could be properly expanded to represent the entire civilian population of South Africa. The weights are the result of calculations involving several factors, including original selection probabilities, adjustment for non-response, and benchmarking to known population estimates from the Demographic Analysis division of Stats SA.
Final survey weights
The final survey weights are constructed using regression estimation to calibrate to the known population counts at the national level population estimates (which are supplied by the Demographic Analysis division) cross-classified by 5-year age groups, gender and race, and provincial population estimates by broad age groups are used for calibration weighting. The 5-year age groups are: 0–4, 5–9, 10–14, 55–59, 60–64, and 65 and over. The provincial level age groups are: 0–14, 15–34, 35–64, and 65 years and over. The final weights are constructed in such a manner that all persons within a household would have the same weight.
Dates of collection
Mode of data collection
Data collection supervision
To facilitate continuous data collection, training and fieldwork monitoring from the regional offices across the country, 332 permanent field staff were appointed to conduct the QLFS. In addition, 95 contract staff have been recruited to assist in areas such as listing and the capturing of publicity forms.
The QLFS data collection strategy is based on a '0110' approach. The first digit "0" represents the first week of any given month. During this week set-up interviews/publicity and listing maintenance is conducted. Data collection is conducted during the middle two weeks "11" of each month (except in January and December). The last week "0" is dedicated to completing the work allocation assigned for that month including the listing of growth areas in the sampled Primary Sampling Unit (PSU) identified during the first week. In summary, the "0"represents a non-data collection week and the "1" represents the two weeks of data collection.
The QLFS questionnaire was developed in English. The contents of the QLFS questionnaire are summarised as follows:
-Cover page of the QLFS core questionnaire: The cover page contains details that enable the tracking of the questionnaire and monitoring of fieldwork at Head Office, the Provincial offices and District offices.
-Section 1 of the QLFS core questionnaire: This section has socio-demographic questions which are completed for all household members regardless of age.
-Section 2 of the QLFS core questionnaire: The questions in this section determine those individuals, aged 15-64 years, who are employed and those who are not employed.
-Section 3 of the QLFS core questionnaire: This section determines which respondents are unemployed and which respondents are not economically active.
-Section 4 of the QLFS core questionnaire: This section contains questions about the work situation of respondents who are employed. It includes questions about the number of jobs at which the respondent works, the hours of work, the industry and occupation of the respondent as well as whether or not the person is employed in the formal or informal sector, etc.
Future improvement to the questionnaire design and analysis include:
a) Development of a short core questionnaire (59 questions) to reduce respondent fatigue and facilitate dissemination of results on a quarterly basis.
b) Development of automated tables for analysis to ensure minimised manual intervention in the production process.
c) Analysis of key results on a quarterly basis to monitor labour market changes on a regular basis.
d) Provision of link factors to enable historical continuity with the LFS.
e) In-depth analysis of quarterly results on an annual basis.
Statistics South Africa
QLFS uses the editing and imputation module to ensure that output data is both clean and complete. There are three basic components, called functions, in the Edit and Imputation Module:
Function A: Record acceptance
Function B: Edit and imputation
Function C: Clean up, derived variables and preparation for weighting
The purpose of data processing is to ensure that the information collected from the sampled primary sampling units, dwelling units and households (i.e. the boxes containing QLFS questionnaires) are physically received, stored and processed. The aim is to produce a clean dataset that has all the information contained in the questionnaires. One important innovation that is central to the smooth operation of the entire system is the development of barcodes that are linked to a unique number on each questionnaire. This information provides the link between the information recorded in the Master Sample database and other processes such as editing and imputation as well as weighting and variance estimation.
QLFS data processing is continuous, starting on the second week of every month. Data processing for each quarter must be completed by the first Friday of the subsequent month to ensure that the four-week deadline for publication of the QLFS results is met.
The processing phases listed below occur sequentially. For detailed explanations of each of the phases, refer to the "Quarterly Labour Force Survey Guide" that is provided as an external resource.
-Receiving of questionnaires
-Automated editing and imputation
-Electronic systems for processing
-Stores Management System (SMS)
-Electronic coding system
-Updating and image retrieval system
-Master Sample capturing system
-Head Office Processing System (HOPS)
Because estimates are based on sample data, they differ from figures that would have been obtained from complete enumeration of the population using the same instrument. Results are subject to both sampling and non-sampling errors. Non-sampling errors include biases from inaccurate reporting, processing, and tabulation etc., as well as errors from non-response and incomplete reporting. These types of errors cannot be measured readily. However, to the extent possible, non-sampling errors can be minimised through the procedures used for data collection, editing, quality control, and non-response adjustment. The variances of the survey estimates are used to measure sampling errors.
Use of the dataset must be acknowledged using a citation which would include:
- Identification of the Primary Investigator,
- Title of the survey (including country, acronym and year of implementation),
- Survey reference number,
- Source and date of download.
Statistics South Africa. South Africa Quarterly Labour Force Survey (QLFS-Q2) 2013, Second Quarter 2013. Ref. ZAF_2013_QLFS-Q2_v02_M. Dataset downloaded from [url] on [date].
Disclaimer and copyrights
The user of the data acknowledges that the original collector of the data, the authorized distributor of the data, and the relevant funding agency bear no responsibility for use of the data or for interpretations or inferences based upon such uses.
The World Bank Microdata Library
Statistics South Africa
Development Data Group
Documentation of the DDI
Version 02 (April 2014)
This version is identical to Version 01, with revisions to data.