Data Appraisal
In 2001, SESE was conducted in March and the SESE interview was undertaken immediately after the LFS interview while the enumerator was still at the dwelling unit. In 2009, 2013 and 2017, data collection for the QLFS occurred during the middle two weeks of the month throughout the quarter, while SESE data collection was undertaken in the last week of the month, also throughout the quarter. In 2005, data collection occurred in September over a two-week period while in 2001 information was collected from respondents in March. Because of these changes in the methodology, comparisons should be interpreted with caution.
The 2001 and 2005 SESE estimates have been revised, using the revised LFS estimates. The LFS estimates were revised after the introduction of the QLFS. The 2001 and 2005 datasets only covered those aged 15-64 years, while in 2009, 2013 and 2017, all persons aged 15 years and above were included.
The 2009 SESE estimates have been revised by StatsSA based on new population benchmarks from the 2011 Population Census. However, the 2005 SESE estimates have not yet been adjusted to reflect the new population benchmarks. The adjustment process in this regard is more complex since it involves the computation of new link factors to align the historical LFS series (2000 to 2007) to the QLFS series. Caution is therefore required when interpreting trends based on the absolute numbers which include the 2005 results.