"As a longitudinal survey, the ELMPS attempts to track households included in the previous waves and interview all their remaining and new members. The survey also tries to locate any individuals who may have split from these households between waves, and attempts to interview them, as well as any other individuals found in the households they formed or joined.
In every wave of the survey, a refresher sample of 2,000-3,000 households is added to maintain the representativeness of the overall sample and to allow for a more in-depth examination of phenomena of interest. The focus we selected for the 2018 wave of the ELMPS was economic vulnerability among Egypt's poorest communities. Accordingly, we added a refresher sample of 2,000 households that oversampled rural communities that were among the "1,000 poorest villages" of Egypt, as ascertained by the most recent national poverty map available to us.
The final sample included 15,746 households and 61,231 individuals. Of these households, 13,793 households included members from 2012 (10,042 panel and 3,751 split households) and 1,953 were refresher households. Among individuals, 53,040 were in households that included at least one individual interviewed in 2012 (i.e., either panel or split households), while 8,191 were in refresher households. Of the 49,186 individuals included in the 2012 sample, 39,153 (79.6%) were successfully re-interviewed in 2018.
Of the 37,140 individuals in the 2006 sample, 22,901 (61.7%) were successfully tracked over three waves. Finally, of the 23,997 individuals included in the 1998 wave, 10,145 (42.3%) were successfully tracked over four waves. We present a detailed discussion of sample attrition patterns in Section 2 and the creation of weights to address such attrition in Section 3. We also discuss the design of the refresher sample and the calculation of the weights for it. In the subsequent section, we compare the (weighted) results of the ELMPS on key demographic and labor market indicators to those of other data sources, namely Egypt's 2017 Census and various rounds of the LFS. First, however, we discuss the design of the questionnaires, sample, and fielding practices." (Krafft, C., Assaad, R., and Rahman, K. ,2019)
For details on The Pattern of Attrition from 2012 to 2018, see:
Krafft, C., Assaad, R., and Rahman, K. (2019) . Introducing the Egypt Labor Market Panel Survey 2018. Economic Research Forum Working Paper No. 1360