1. Tabulation and Dual System of Estimation (DSE) Pres. 9
United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Asunción, Paraguay, 3-7 August 2009

2. Tabulations & Dual System of Estimation (DSE)
Tabulations: Initial tables
Estimated number of non-movers
Estimated number of out-movers
Estimated number of matched non-movers
Estimated number of matched out-movers
Estimated in-movers
Estimated number of erroneous inclusions in the census
Estimated number of correctly enumerated persons
United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Asunción, Paraguay, 3-7 August 2009 2

3. Basic Tabulations for Coverage Analysis
Tabulations for coverage estimates (by age group & sex)
E-sample estimates of population enumerated in the census
P-sample estimates of total population
Census omissions & census omission rates
Census erroneous inclusions & census erroneous inclusion rates
Preliminary DSE of True Population
Net census coverage error and net coverage rate
Gross census coverage error & rate
Final DSE of True Population
United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Asunción, Paraguay, 3-7 August 2009 3

4. Examples - Tabulations for Content Error Estimates
Sex as reported in the census and as reported in the PES for matched persons
Age as reported in the census and as reported in the PES for matched persons
Family relationship as reported in PES for matched persons
NOTE: PES should check content errors only for those items that support PES procedures
United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Asunción, Paraguay, 3-7 August 2009 4

5. Dual System of Estimation (DSE)
Omissions not a complete story in evaluating a census
Census, as earlier stated, can contain duplicates
Census can erroneously enumerate some one who should have been enumerated elsewhere
Fictitious persons - in some cases
Net coverage error
Therefore need to estimate True Population
United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Asunción, Paraguay, 3-7 August 2009 5

6. Dual System of Estimation (DSE) (contd.)
In census
Out of census
In PES
Out of PES
Total
United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Asunción, Paraguay, 3-7 August 2009 6

7. Dual System of Estimation (DSE) (contd.)
Chandrasekaran-Deming estimator (1949) assuming independence
United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Asunción, Paraguay, 3-7 August 2009 7

8. Dual System of Estimation (DSE) (contd.)
The form of DSE used in PES is as follows:
Where C = census count
II = number of persons with insufficient information
CE = estimated number of correct enumeration from the E-sample
Ne = estimated number of people from the E-sample
Np = estimated number of people from the P-sample
M = estimated number of persons from the P-sample population who
matched to the census
United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Asunción, Paraguay, 3-7 August 2009 8

9. Dual System of Estimation (DSE) (contd.)
Coverage rate
This is the matched population relative to estimated PES population
The DSE is usually applied within substrata/subgroups formed e.g. sex and age - groups
United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Asunción, Paraguay, 3-7 August 2009 9

10. Dual System of Estimation (DSE) (contd.)
Erroneous inclusions rate
This is equal to the total number of persons erroneously included in census relative to the Census population estimated by E-sample
United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Asunción, Paraguay, 3-7 August 2009 10

11. Dual System of Estimation (DSE) (contd.)
Matched population
Matched population = Matched non-movers + estimated matched out-movers (thus, in practice, the number of out-movers is assumed to be the same as that of in-movers)
Census population estimate
Census population = Matched non-movers+ matched out-movers + population erroneously included in the census+ population correctly enumerated in the census but missed in the PES
United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Asunción, Paraguay, 3-7 August 2009 11

12. Dual System of Estimation (DSE) (contd.)
Estimated PES population
PES population = Census + omission – Erroneous
PES population = Number of non-movers + in-movers
Omission population
Omissions = PES population - (Census – erroneous) = PES population - Census + Erroneous
United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Asunción, Paraguay, 3-7 August 2009 12

13. Dual System of Estimation (DSE) (contd.)
Omission rate
Is the missed population between the census and PES relative to PES population
United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Asunción, Paraguay, 3-7 August 2009 13

14. Dual System of Estimation (DSE) (contd.)
True population
True Population = estimated PES population multiplied by population from the census after subtraction of erroneous enumerations and divided by matched population between the census and the PES
United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Asunción, Paraguay, 3-7 August 2009 14

15. Dual System of Estimation (DSE) (contd.)
Net coverage error
The difference between what should have been counted, thus True Population and what was counted in the census
Net Coverage rate
The measure is the total net error relative to the DSE estimate of the true population (an important indicator of the quality of census coverage)
United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Asunción, Paraguay, 3-7 August 2009 15

16. Dual System of Estimation (DSE) (contd.)
Gross coverage error
The sum of Omissions and Erroneous Inclusions
Gross coverage error rate per unit enumeration
This is the absolute gross error relative to census enumerated population
United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Asunción, Paraguay, 3-7 August 2009 16

17. Evaluation of Content Error
Net difference rate (NDR)
The NDR is the difference between the number of cases in the census and number of cases in the PES that fall under a category (e.g. age-group) relative to the total number of matched persons in all response categories
United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Asunción, Paraguay, 3-7 August 2009 17

18. Evaluation of Content Error (contd.)
Index of inconsistency
It is a relative number of cases for which the response varied between the census and PES. In a n x n table, numbers in diagonal cells show consistency (agreement). Off diagonal numbers represent inconsistency. This is calculated for each response from a category
United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Asunción, Paraguay, 3-7 August 2009 18

19. Evaluation of Content Error (contd.)
Other measures include:
It is Aggregate index of inconsistency
Gross difference rate
Rate of agreement
United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Asunción, Paraguay, 3-7 August 2009 19

20. How to interpret content error measures
Index
Low
Moderate
High
Absolute value of NDR
< 0.01
>0.05
Index of Inconsistency
<20
20-50
>50
Aggregate Index of Inconsistency
United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Asunción, Paraguay, 3-7 August 2009 20

21. Thank You!
United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Asunción, Paraguay, 3-7 August 2009