Sampling Procedure
The Employment and Earnings Survey of 2002 used the existing Central Register of Establishments (CRE) frame. The selection of establishments from the CRE frame falls under the following groups: - (i) All establishments of the public sector found in the CRE frame of 2002. (ii) All establishments of the private sector with at least 50 employees found in the CRE frame of 2002. (iii) Samples of establishments of the private sector employing 5 to 49 persons.
Weighting
The weights were adjusted to suit the response status of the category of employment involved in the respective region.
The sampling weights for the strata were calculated using simple expansion formula denoted as:-
Weight = N/n where,
N = Total number of establishments in the stratum
n = Number of selected establishments
To account for non response, the sampling weight is adjusted as shown bellow:
Weight = (Nhij * (1 - (a hij/nhij)))/(nhij- a hij)
where,
Nhij = Total number of establishments in sector j of region i in stratum h where, j = 1…3, i = 1…20
and
h = Either employment size 5-9 or employment size 10-49
nhij = Number of selected establishments in sector j of region i in Stratum h where: j = 1…3, i = 1…20 and
h = either employment size 5-9 or employment size 10-49
ahij = Number of non-responding establishments in sector j of region i in Stratum h where: j = 1…3, i = 1…20 and h = either employment size 5-9 or employment size 10-49
h = Stratum (the survey dealt with two strata).
i = Region (the survey dealt with 20 regions)
j = Private sector (the survey dealt with three sub sectors)
Estimation of Totals is given by:
Yhij = ßhij * ( N hij * ( 1 - (ahij/ n hij))/ ( nhij - ahij)
Where:
ßhij = Responded establishments in sector j of region i in Stratum h j = 1…3, i = 1…20 and h = either 5 - 9 or 10 -49
