Post-Enumeration Survey –
Requirements, Planning,
Designing and Executing
Carlos Creva Singano, National Statistic Office,
Mozambique -Maputo
Adis Ababa Workshop 14-18 September
2009
Mozambique Carlos C. Singano
1. Requisite qualities of PES
• All Census questionnaires must be returned from the
field in all EA to National Statistic Office, before the
PES field enumeration.
• The processing of the PES data must be separate
from the general Census of Population and Housing
processing Data;
• The PES staff must go to the field without knowing the
preliminary results of the respective EA;
• To take the advantage of General Census enumerators
and supervisors, they must be used as the field staff;
Carlos C. Singano Mozambique Maputo
2
2. Costs /Other resources
• The costs must be fixed based on the sample size, mainly at
the first stage of sampling ( that is, nº of PSU to be selected)
as well as the nº of Domains of Estimation;
• The items to be included in the global cost are:
-Transportation (Vehicles & its maintenance)
- Field staff (PES enumerators; PES supervisors; PS
Drivers);
- Office Personnel (Matching clerks, matching
Supervisors, Data Entry operators, Data Entry supervisors)
- Printing and Reproduction (Questionnaires; Manuals,
Maps, List of EA, etc)
Carlos C. Singano Mozambique Maputo
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3.Organization structure/Technical
planning
•
Depend on the Political and administrative structure:
• Mozambique:
- NSO (Central Level- Sample Design, Budget and its distribution by
province according to the sample size);
- Provincial Level ( Only for execution of the central directives;
controlling the field staff and financial matters); To control the
Quality in the enumeration in the dual system;
•
In Mozambique, the Province is a domain of estimation. The sample
must be representative of strata within each province;
• In each 11 Provinces, the NSO has a Provincial NSO for Operations
issues.
Carlos C. Singano Mozambique Maputo
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4.Procedure for Covarage analysis
• There are Three Procedures for evaluation Census coverage
in PES: Procedures A, B and C ( See Manual “ Evaluating
Censures of Population and Housing”;
• Mozambique used the procedure C, where the goal was to
identify all current member of the sample HH as the 2007
PES date; in addition, any other resident as of the Reference
Date of the General 2007 census of Population and Housing.
• These persons are classified as either non-mover, out-mover
and in-mover (that is, to identify immigrants and
emigrants), with regard to their HH memberships status as
of the 2007 Census Date.
• In the 2007 Census records, only the Residents as the
Date of the 2007 Census (the Non-movers and the
Out-Movers), were matched.
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4. Procedure for Covarage analysis (Cont.)
• 2007 PES Status Mozambique
- Non-mover;
- Out-mover;
- In-Mover;
- Bor After
Some Definition:
 Those who belonged to the HH as of the 2007 General
Census and still as of the 2007 PES are the “Non-Movers”;
 Those who became members of a different HH during the
interim period between the 2007 General Census and the
2007 PES are the “Movers”. There are two types of Movers:
 The “In-Movers” - those who arrived in the HH after 2007
Census;
 The “Out-Movers” - those who have left the HH since the
2007
CarlosCensus.
C. Singano Mozambique Maputo
6
4. Procedure for Covarage analysis (Cont.)
(Some Definitions)
 Persons who do not belong to the target population, that is,
the population as of the 2007 Census date are considered
“Out-of-scope”. This includes persons born after the 2007
census or persons who died before the 2007 Census,aliens
and nonresidents. No match is attemted or Out-of Scope.
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5.Organization structure/Technical planning
(Sample Size and Domain of estimation)
• Depending on the main objectives to be measure (the
coverage error or, the net omission rate), the geographic
domains of analysis and financial resources, the sample size
is fixed;
• In Mozambique, the Domains of estimation are: Provinces;
National and national Urban and national Rural;
• The 2007 PES of Moz follow a Stratified Cluster sampling of
340 PSU: Minimal of 30 PSU by Province and Maxim of 40
PSU in Maputo, Capital of Mozambique. All unit of analysis
(HH, persons, etc) in each sample PSU were interviewed;
• Sample designing for 95 percent of Confidence;
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5.Sample Size and Domain of estimation
(Cont.)
Province/Domain
of Estimation
Niassa
Cabo Delgado
Nampula
Zambézia
Tete
Manica
Sofala
Inhambane
Gaza
Maputo Província
Maputo Cidade
MOÇAMBIQUE
Nº of PSU or EAs, 2007 PES
Urbano
Total
30
8
30
6
30
8
30
5
30
5
30
9
30
14
30
7
30
8
30
21
40
40
340
Carlos C. Singano Mozambique Maputo
131
Rural
22
24
22
25
25
21
16
23
22
9
0
209
9
5.Sample Size, Domain of estimation and
estimates(Cont.)
• Within each Province, the sample was stratified by urban and
rural areas;
• The Sample selection within each strata was selected
independently with PPS. Measure of size was the nº of
household within each strata;
• Using the Dual system methodology (Procedure C), coverage
and sampling errors were estimated. The national coverage
error was 2.1 per cent. The Programme used were CENVAR
(The IMPS Component) to main variables (eg, Age, sex,
marital status, etc).
• David Megill, The U.S.Census Bureau statistician, did help
the Mozambican staff to do it;
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5. Sample Size, Domain of Estimation and
estimates(Cont.)
• 95 percent confidence intervals for the Census omission rate
were estimated;
Carlos C. Singano Mozambique Maputo
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6. Sampling Frame and Units of Analysis
• Methodology of 2007 Moz PES: Two-way HHs and HHs
Members;
• The target universe included only the individual households
in Mozambique;
• Quarters groups were excluded of the scope;
• The units of analysis in Mozambique 2007 PES were
Households members
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6.Sampling Frame and Units of Analysis
• Distribution of the HH in Mozambique by Province and area
of residence. Preliminary Results
Total
Province
HHs.
Niassa
258,090
Cabo Delgado
406,418
Nampula
951,523
Zambézia
918,808
Tete
427,126
Manica
276,251
Sofala
346,589
Inhambane
297,956
Gaza
251,185
Maputo Província
276,936
Maputo Cidade
222,285
Moçambique
4,633,167
Urban
HHs.
%
61,175 23.7%
72,744 17.9%
261,848 27.5%
155,391 16.9%
58,820 13.8%
69,057 25.0%
151,591 43.7%
87,248 29.3%
74,707 29.7%
177,962 64.3%
222,285 100.0%
1,392,828 30.1%
Carlos C. Singano Mozambique Maputo
Rural
HHs.
196,915
333,674
689,675
763,417
368,306
207,194
194,998
210,708
176,478
98,974
0
3,240,339
%
76.3%
82.1%
72.5%
83.1%
86.2%
75.0%
56.3%
70.7%
70.3%
35.7%
0.0%
69.9%
% Urban
1997
Census
20.3%
14.9%
23.0%
13.8%
13.3%
26.6%
40.3%
20.0%
23.4%
57.7%
100.0%
26.3%
13
6. Sampling Frame and Units of Analysis
• Distribution of the PSU or EAS by Size oh HHs in Mozambique by
Province and area of residence. Preliminary Results
HHs in the Frame
0-9 Hhs.
10-19 Hhs.
20-49 Hhs.
50-99 Hhs.
100-149 Hhs.
150-199 Hhs.
200-299 Hhs.
300-499 Hhs.
500-999 Hhs.
1000-1999 Hhs.
2000 Hhs. +
Carlos C. Singano Mozambique
Total
Nº of PSUs or Eas
Total
Urban
Rural
281
85
196
446
59
387
5,008
629
4,379
19,133
3,637
15,496
13,789
4,252
9,537
4,253
1,813
2,44
1,578
685
893
338
154
184
58
30
28
35
9
26
8
3
5
Maputo44,927
14
11,356
33,571
6. Sampling Frame, Units of Analysis,
Sample Selection Methodology
• The Sampling frame is stratified by Province Urban and
rural;
• The objective of this stratification is to improve the PES
Sample Design;
• The PSU or EA within each strata was selected by PPS. The
number of HH within each was the measure of size.
• An implicity stratification by political subdivision (OER Cod,
CA_Cod and EA_Cod) was done before sample selection
within each strata;
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7. Development of Questionnaire and field
manuals
• The Moz PES questionnaire was based on the final 2007
General census of Population and Housing Questionnaire;
• The 1997 PES (Moz) and the 1991 PES (Ruanda) were used
as Reference;
• Demographics characteristics included in 2007 PES:
 Marital status, age, sex and relationships to the head of the
HH and
 the section A of the General Census, that is, the location
and area of residence of the HH to facility the matching
process;
 To facility the comparability between 2007 Census data and
2007 PES data, same response categories and precoding
system were used;
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7. Development of Questionnaire and field
manuals (Cont.)
• To facility the field team (enumerators and supervisors), a
small Manual with instructions, definitions was prepared;
• The PES data collection aims were to identify all usual
residents at the time of the 2007 Census in addition to those
as of the date of the 2007 PES ( Procedure C in Slide 5-6).
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8. Budgeting/ Pilot test
• The 2007 PES Budget Was planned as part of the 2007
census program;
• The 2006 PES Pilot was care out to test the Dual System
methodology (Procedure C) of the 2007 Census of
Population and Housing. This was done during the Pilot
General Census of Population and Housing in 2006;
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9. Selection and training of field staff/
data collection
• To take the advantage of 2007 General Census enumerators
and supervisors, those were used as the field staff of 2007
PES;
• They were trained during two days in each province.
• The 2007 PES data collection did take place 15 days after
2007 General Census data collection. The objective was to
minimize the matching difficulties processes related to the
changes to the composition of the HHs between the two
Dates.
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10. Omission rates for 2007 Census of
Population and Housing
Domain/ Province
Mozambique
Area of Residence
Urban
Rural
Province
Niassa
Cabo Delgado
Nampula
Zambézia
Tete
Manica
Sofala
Inhambane
Gaza
Maputo Province
Maputo City
95 % Confidence
Interval
Inferior
Sup
.017
.024
Estima
te
.021
Standard
Deviation
.002
CV
Deff
.077 19.469
Nº of
cases
155819
.021
.020
.002
.002
.017
.016
.025
.024
.105 11.554
.101 23.162
74867
80952
.037
.008
.020
.053
.229 16.520
11894
.019
.027
.013
.015
.016
.030
.005
.004
.003
.003
.005
.009
.008
.019
.007
.009
.007
.012
.029
.035
.019
.021
.025
.047
.289
.156
.220
.198
.299
.296
15.943
22.377
17.445
6.996
17.400
40.461
10086
12326
11184
10609
14529
16461
.027
.007
.007
.001
.012
.005
.042
.010
.279 21.112
.142 1.354
12621
11978
.017
.016
.003
.002
.012
.012
.023
.021
.173
.135
18508
25623
Carlos C. Singano Mozambique Maputo
5.975
2.851
20
End
Kanimambo
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