Final Report—Appendix C: the Design of The
Total Page:16
File Type:pdf, Size:1020Kb
APPENDIX C: THE DESIGN OF THE SYPE SAMPLE AND THE CALCULATION OF SAMPLING WEIGHTS The sample of the Survey of Young People in Egypt 2009 (SYPE) was designed in such a way as to be representative at the national as well as regional levels. The sample size of approximately 17,000 young people between the ages of 10 and 29 was selected to provide estimates of key indicators related to adolescents and youth for the country as a whole and for four administrative regions (Urban governorates, Lower Egypt governorates, Upper Egypt governorates and the Frontier governorates), and, where relevant, for the urban and rural segments of these regions. These indicators include never enrollment rates, dropout rates, the incidence of child labor, and unemployment rates. Based on previous statistics about the incidence of young people in the relevant age and sex groups, we determined that a nationally-representative sample of 11,000 households would be sufficient. To obtain accurate estimates for the Frontier governorates, these governorates had to be oversampled. As a result, the SYPE is not a self-weighted sample and weights are needed to obtain the correct estimates. The weights are derived in Section 2 below. C.1 Sample Design Sample Frame The SYPE sample was designed as a multi-stage stratified cluster sample. The primary sampling units (PSUs) were selected from a CAPMAS master sample. The master sample is a stratified cluster sample that contains 2,400 PSUs, divided into 1,080 urban and 1,320 rural PSUs. These PSUs are drawn from a frame of enumeration areas (EAs) covering the entire country prepared by CAPMAS from the 2006 Population Census. Each EA is drawn up in such a way as to contain roughly 1500 dwelling units. The sample is stratified into governorates and each governorate is further stratified into urban and rural segments, where relevant. The distribution of PSUs across strata in the master sample reflects the distribution of the population so as to produce a self-weighted sample. To achieve a fairly wide geographic dispersion in the SYPE sample and thus minimize the design effect, we set the number of households per cluster to 25. To obtain these 25 households, 25 dwelling units were systematically selected from the roughly 1500 listed in each EA.64 To get the sample size we needed, we set the number of required PSUs to 455, for a total sample size of 11,375 households. The distribution of PSUs across governorates and urban and rural areas in both the master sample and the SYPE sample are shown in Table 1. The final sample of households interviewed was made up of 11,372 households, which yielded a total of 15,029 young people aged 10-29. As shown in Table 1, the PSU’s in the SYPE sample were drawn from the EA’s in the master sample at a rate of roughly 19%-20%. With the exception of the Frontier Governorates and the Luxor administrative area, the sampling rate varies in a relatively narrow range from 14% to 27%. To get good representation from the sparsely populated Frontier Governorates, we increased the sampling rate significantly, in some cases retaining all the PSU’s in the master sample. Weights will be derived at the level of the administrative region to account for these varying sampling rates. 64 An additional 5 to 10 dwelling units per PSU were selected to allow for replacement in case the dwelling could not be located or was found vacant. 264 Survey of Young People in Egypt / January 2011 Selecting the Urban Slums Sub-Sample One of the objectives of SYPE is to obtain separate estimates for young people living in urban slums (referred to in the report chapters as informal urban areas). To make sure we had enough representation of urban slums, we used a study conducted by the Information and Decision Support Center of the Egyptian Cabinet of Ministers (IDSC) to classify urban PSU’s in the CAPMAS master sample into slum and non-slum areas. Deciding how to allocate urban PSUs to slum and non-slum areas was not a straightforward exercise given the unreliability of the data on the population of the slum areas. Table 1: Distribution of primary sampling units across governorates and urban/rural areas in CAPMAS master sample And SYPE sample Enumeration Areas in Sampling Rate from Master PSUs in SYPE Sample CAPMAS Master Sample Sample Governorate Total Urban Rural Total Urban Rural Total Urban Rural Urban governorates Cairo 285 285 0 55 55 0 19% 19% -- Alexandria 149 149 0 25 25 0 17% 17% -- Port Said 20 20 0 4 4 0 20% 20% -- Suez 17 17 0 4 4 0 24% 24% -- Lower Egypt Damietta 39 15 24 8 3 5 21% 20% 21% Dakahlia 176 50 126 29 8 21 16% 16% 17% Sharkia 175 42 133 29 7 22 17% 17% 17% Qalioubia 145 56 89 21 8 13 14% 14% 15% Kafr El Sheikh 85 20 65 17 4 13 20% 20% 20% Gharbia 139 44 95 25 8 17 18% 18% 18% Menoufia 107 23 84 21 5 16 20% 22% 19% Behira 152 31 121 23 4 17 15% 13% 14% Ismailia 31 15 16 8 4 4 26% 27% 25% Upper Egypt Giza 215 130 85 34 21 13 16% 16% 15% Beni Suef 69 17 52 13 3 10 19% 18% 19% Fayoum 78 19 59 13 3 10 17% 16% 17% Minya 128 26 102 23 4 17 18% 15% 17% Assiut 101 28 73 17 5 12 17% 18% 16% Souhag 114 25 89 21 5 16 18% 20% 18% Qena 88 20 68 17 4 13 19% 20% 19% Aswan 37 16 21 8 3 5 22% 19% 24% Luxor 14 7 7 8 4 4 57% 57% 57% Frontier Governorartes Matrouh 8 6 2 8 6 2 100% 100% 100% New Valley 6 3 3 6 3 3 100% 100% 100% Red Sea 9 8 1 6 5 1 67% 63% 100% North Sinai 10 6 4 9 5 4 90% 83% 100% South Sinai 3 2 1 3 2 1 100% 100% 100% Total 2400 1080 1320 455 212 239 19% 20% 18% 265 Survey of Young People in Egypt / January 2011 Table 2: Distribution of urban slum areas nationally and in SYPE sample Distribution of all Distribution of urban National distribution urban PSU's in SYPE slum PSU's in SYPE Distribution of urban non- of slum areas sample sample slum PSUs in SYPE sample Governorate Number Percent Urban Percent Number Percent Number Percent Cairo 74 8% 55 26% 4 9% 51 30% Alexandria 29 3% 25 12% 2 5% 23 14% Port Said 3 0% 4 2% 0 0% 4 2% Suez 3 0% 4 2% 0 0% 4 2% Damietta 37 4% 3 1% 2 5% 1 1% Dakahlia 119 12% 8 4% 6 14% 2 1% Sharkia 82 9% 7 3% 4 9% 3 2% Qalioubia 58 6% 8 4% 3 7% 5 3% Kafr El Sheikh 49 5% 4 2% 3 7% 1 1% Gharbia 48 5% 8 4% 3 7% 5 3% Menoufia 45 5% 5 2% 2 5% 3 2% Behira 71 7% 4 2% 4 9% 0 0% Ismailia 12 1% 4 2% 1 2% 3 2% Giza 29 3% 21 10% 2 5% 19 11% Beni Suef 38 4% 3 1% 2 5% 1 1% Fayoum 28 3% 3 1% 1 2% 2 1% Minya 75 8% 4 2% 4 9% 0 0% Assiut 0 0% 5 2% 0 0% 5 3% Souhag 22 2% 5 2% 1 2% 4 2% Qena 0 0% 4 2% 0 0% 4 2% Aswan 7 1% 3 1% 0 0% 3 2% Luxor 12 1% 4 2% 0 0% 4 2% Matrouh 30 3% 6 3% 0 0% 6 4% El Wadi El 5 1% 3 1% 0 0% 3 2% Gedid Red Sea 47 5% 5 2% 0 0% 5 3% North Sinai 36 4% 5 2% 0 0% 5 3% South Sinai 0 0% 2 1% 0 0% 2 1% Total 959 100% 212 100% 44 100% 168 100% First, we had to make a decision on how to allocate the 212 urban PSUs to slum and non- slum PSUs. The most reasonable estimate of the share of slums in the urban population was close to 20%, leading us to allocate 44 of the 212 urban PSU’s in the sample to slum areas. Second, we had to allocate these 44 slum PSUs to the various governorates. This allocation was done in such a way as to match as closely as possible the distribution of the number of slum areas across governorates as shown in Table 2. Ideally, we should have allocated slum PSUs across governorates according to each governorate’s share of slum population rather than its share in the number of slum areas. However, given the unreliable information about 266 Survey of Young People in Egypt / January 2011 the population of slum areas, it was impossible to do the allocation in terms of population. This allocation decision is likely to understate the true share of slums in governorates such as Cairo, Giza and Alexandria, where the size of slums is likely to be larger than average, and overstate slum populations in governorates like Damietta, Dakahlia and Sharkia where the size of slums is probably smaller than average. Without reliable data on slum populations, it is unfortunately not possible to use weights to correct for this possible bias in the geographic distribution of slums. C.2 Sampling Weights and Expansion Factors Three sampling weights are included in the SYPE database: (i) the household sampling weight, (ii) the roster individual sampling weight and (iii) the interviewed individual sampling weight.