1. www.scad.ae Optimum sampling strategy for National Households In Abu Dhabi (The Household Master Sample 2012) Authors : Mohammed Al Rifai (Ph.D.) Mariam Al Qemzi 21/August/2014

2. www.scad.ae Contents  Introduction  Problem Identification  The Structure Of Abu Dhabi Sampling Frame  Stratification Of The Master Sampling Frame  Household Nationality Strata  Master Sample Size And Allocation  Proposed Allocation Criteria By Nationality Strata  Conclusion 2

3. www.scad.ae The Emirate of Abu Dhabi Almost 43 years since the formation of the UAE. UAE comprises Abu Dhabi plus six other Emirates. Abu Dhabi accounts for over 80 per cent of UAE land mass. Abu Dhabi contains around one third of UAE population. Emirati citizens make up around 20 per cent of Abu Dhabi population. Abu Dhabi oil represents around 10 per cent of global reserves. Statistics Centre – Abu Dhabi SCAD is the official source of statistical data for Abu Dhabi. Our Mission: 1. Develop and organize a statistical system in the Emirate. 2. Provide relevant and reliable official statistics serving policy makers, the business community and the public. 3. Celebrated five years of operation in April 2014. 4. Operates in accordance with international best practice to provide range of statistics. 3 Introduction

4. www.scad.ae The problem: “ How to improve the sample strategy for national households to ensure accuracy? ” 4 Problem Identification

5. www.scad.ae The Structure Of Abu Dhabi Sampling Frame 5 Abu Dhabi Emirate Regions (3) Districts (117) Sectors (1000) EA (1883)

6. www.scad.ae The Structure Of Abu Dhabi Sampling Frame RegionTotal No. EAs % All Households % National Households % Non National Households % Shared Households Abu Dhabi 1,21564.45870.252.8 Al Ain 55129.23723.638.4 Al Gharbia 1176.456.28.7 Total 1,883100 6

7. www.scad.ae Stratification Of The Master Sample Frame Homogeneity of EA within Strata. Key Domains of Analysis: –Region –Citizenship Levels of stratification of EAs: 7 Level 1 Geographic domains which are the three regions of Abu Dhabi Emirate Level 2 Concentration of National households within each region

8. www.scad.ae Households Nationality Strata The nationality strata are as follows: 8 Stratum Concentration of National Households Total No. of EAs % National Households for the stratum % All Households 10 to 24.9% 1,3157.369.9 225 to 49.9% 25535.813.1 350 to 74.9% 19961.711.1 475% or more 11483.75.9 Total 1,88321.5100

9. www.scad.ae Master Sample Size And Allocation Master Sample size: Number of PSUs in the master sample should be sufficiently large to provide sample households for: Household surveys that are currently planned. Future Surveys – may require larger samples 4 Replicates. Result - A sample of 560 EAs. This represents nearly 30% of all EAs used in Census 2011. 9

10. www.scad.ae Master Sample Size And Allocation Master sample allocation: Allocation by region based on: –previous sampling errors for key statistics. –4 Replicates EA allocation: 10 EA countRegion 320Abu Dhabi 160Al Ain 80Al Gharbia 560Total

11. www.scad.ae The Proposed Allocation Criteria By Nationality Strata The modified proportional allocation criteria can be expressed as follows: 11 Where: n h = number of sample EAs allocated to stratum h. n = total number of sample EAs W h = weight assigned to nationality stratum h N h = total number of households in nationality stratum h N = total number of households in frame

12. www.scad.ae The Proposed Allocation Criteria By Nationality Strata 12 4321Stratum 75 – 100%50 - 74.9%25 - 49.9%0 – 24.5% Concentration of National Households 5.9%11.1%13.1%69.9% % of All households 83.7%61.7%35.8%7.3% % National households 4321 Allocated weights

13. www.scad.ae Conclusion 13 % National Households using proportional Allocation: 21.5% % National Households using Modified Allocation: 35.6% Implementation: high level of precision in LFS2012 Sample EAs by Region and Nationality Strata Region Nationality Stratum Estimated % National Households in Sample Total1234 Abu Dhabi32015558674033.3% Al Ain1606523393340.6% Al Gharbia80392210929.9% Total5602591031168235.6%

14. www.scad.ae For more information please read the paper. Website: www.scad.aewww.scad.ae Authors: 14 Contact

15. www.scad.ae 15