Sampling procedure
<p style="border:solid thin black;"> THE CLEANED AND HARMONIZED VERSION OF THE SURVEY DATA PRODUCED AND PUBLISHED BY THE ECONOMIC RESEARCH FORUM REPRESENTS 100% OF THE ORIGINAL SURVEY DATA COLLECTED BY THE PALESTINIAN CENTRAL BUREAU OF STATISTICS</p>
The methodology was designed according to the context of the survey, international standards, data processing requirements and comparability of outputs with other related surveys.
---> Target Population:
It consists of all Palestinian households and individuals who habitually reside with their households in Palestine for the reference period of the survey, which is 2018, and there was a focus on individuals of the age group 18 years and over to complete an additional form for individuals in this category.
---> Sampling Frame:
The sampling frame consists of a comprehensive sample selected from the Population, Housing and Establishments Census 2007: This comprehensive sample consists of geographical areas with an average of 124 households, and these are considered as enumeration areas used in the census and these units were used as primary sampling units (PSUs).
---> Sampling Size:
The estimated sample size is 9926 households in 2018.
---> Sample Design
The sample is two stage stratified cluster sample with three stages :
First stage: a systematic random sample of 337 enumeration areas for the whole round was selected.
Second stage: the same households that were visited in the previous survey session 2015, which are about 25 households from each enumeration area were visited in 2018. Households that changed their place of residence and address available in the previous database to another place to complete the questionnaire are tracked. Individuals from the previous session who were separated from their household and formed new households or joined new households.
Third stage: a male or female individual was selected from all sample families (old and new) in the second stage of individuals 18 years and over using check tables to complete the form for individuals 18 years and over (quality of life model). Taking into account that the household whose number is even in the enumeration area sample, we choose a female from it, and the household whose number is odd, from which we choose a male.
---> Sample strata:
The population was divided by:
1. The governorate (16 governorates in the West Bank, including Jerusalem J1 governorate, which the Israeli occupation annexed to it by force after its occupation of the West Bank in 1967 as Tabqa and the Gaza Strip).
2. Type of settlement (urban, rural, camp).
3. Area C (class C, non-C) as an implicit class.
Response rates
The survey sample consists of about 11,008 households of which 9,926 households completed the interview; whereas 5,898 households from the West Bank and 4,028 households in Gaza Strip. Weights were modified to account for non-response rate. The response rate in Palestine reached 90.2%.
Weighting
The weight of statistical units (sampling unit) in the sample is defined as the mathematical inverse of the selection probability where the sample of the survey is a three-stage stratified cluster systematic random sample. In the first stage, the weight of enumeration areas is calculated based on the probability of each enumeration area. In the second stage, the weight of households in each enumeration area is calculated. Initial household weights resulted from the product of the weight of the first stage and the weight of the second stage. Then the initial weight is adjusted by producing the initial weight and the attrition factor (attrition from the sample). The final household weights were obtained after adjustment of the initial weights with the household estimates for mid-2018 according to design strata (governorate, locality type).
Weights of households members’ portfolio are calculated by giving every member the final weight of his/her household, which is the primary individual/member weight. Primary Individual/Member’s Weight is then adjusted according to area, gender and age groups (17 groups) representing the age of individual/member by mid-October 2018. This enabled to obtain the individual/member’s final weight in his/her category. The weights are then merged in the individual/member’s portfolio for individuals aged 18 and above.