C.
SURVEY METHODS
a.
The Sampling Method
The main sample of the survey is drawn once a year in two stages. In the first stage, a
sample of localities is drawn (about 235 each year), in which the selection probability is
proportional to the size of the locality. In the second stage, a sample of dwellings in those
localities is drawn, in which every dwelling has the same sampling probability. In most of the
urban localities, the sample of dwellings is derived from the municipal tax files of the local
authorities. For localities that do not have municipal tax files, a sample is drawn from a list of
households obtained from the locality.
The main sample is supplemented by dwelling units that are not covered by the municipal
tax files and lists of households. The supplements include:
 A current supplement of new dwellings occupied after updating of municipal tax files;
 a current supplement of households in East Jerusalem, drawn after mapping of
enumeration cells from the 1995 Population and Housing Census;
 a current supplements of dwelling units in student dormitories, absorption centres, and
hotels that house new immigrants.
 a fixed supplement of persons and households in other institutions and in small localities
that are not covered by the current survey samples, which is derived from the 1995
Population and Housing Census files.
b.
The Estimation Method
The data collected in the survey are entered, checked, and coded. Following these
procedures, estimates are calculated from each quarterly sample as explained below. The
annual estimates presented in this publication are arithmetic means of the four quarterly
estimates.
To derive estimates for the total survey population, the data obtained in the sample are
weighted appropriately for each respondent. For that purpose, the population is divided into
weighting groups, defined by age*sex*locality group.
The estimation method is designed to minimize sampling errors and biases that may arise
from “non-respondent households”, which may have characteristics that differ from those of
the households that participated in the survey.
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As of 1999, a new estimation method has been used. According to the new method, a
“weighting coefficient” is calculated for each surveyed household in order to obtain estimates
relating to the total survey population. The weighting coefficient is equivalent to all of the
persons belonging to the same household. The weighting coefficient for each household
reflects the number of households and the number of persons in the survey population
represented by the household. This is in contrast to the estimation method used up to 1999,
in which persons were weighted independently of the composition of the household.
Therefore, the weights within the same household were not uniform.
The weighting coefficients are determined in an iterative process, which results in complete
compatibility between the weighted distribution of persons and the current demographic
estimates of the Central Bureau of Statistics, which are based on the 1995 Census, and are
derived according to the defined weighting groups. In 2002, some changes were introduced
in the definition of weighting groups. For further explanations, see: Central Bureau of
Statistics, Labour Force Surveys 2002, Special Publication 1218, Jerusalem, 2004, Chapter
B in the Introduction.
In the Labour Force Surveys, which have been conducted since 1954, the methods of
sampling, estimation, and investigation have changed over the years. The description of
methods in this section relates to the situation that has existed since the changes were
introduced following the receipt of a revised estimate for 1998, which was based on the
results of the 1995 Census of Population and Housing.
The changes in the methodology, definitions, and in the survey questionnaires which
occurred between 1954 and 2003 have been summarized in a special technical publication –
see Central Bureau of Statistics, Labour Force Surveys: Changes in the Methodology,
Definitions, and Questionnaire 1954-2003, Technical Publication No. 78. For explanations on
the changes in methodology that were introduced following the 1995 Census of Population
and Housing, see: Central Bureau of Statistics, Labour Forces 2000, Special Publication No.
1176, Introduction, Section E. For changes that were introduced following the 1983 Census
of Population and Housing, see: Central Bureau of Statistics, Labour Force Surveys 1985,
Special Publication 801, Appendix B.
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