Methodologies and Procedures for Evaluating Coverage and Content Error Pres. 6 United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Addis Ababa, Ethiopia, 14-18 September 2009

Methodologies & Procedures for Evaluation PES basically involves two overlapping P- and E- samples P sample areas disclosed only need to know basis P and E samples data collection occurs at different times Mover procedures A, B, & C United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Addis Ababa, Ethiopia, 14-18 September 2009 2

What is a P sample? The Population (P) consists a sample of clusters drawn from the same population but independent from the census Independently listed units that are valid and unique Results used to estimate census omissions United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Addis Ababa, Ethiopia, 14-18 September 2009 3

What is an E sample? The E sample is a sample drawn from cases already enumerated in the census Housing units enumerated in the census in the same sample area as the P-sample It is not uncommon to have an overlap of the E and P samples Results used to estimate census erroneous inclusions Estimate of erroneous inclusions provides a correction factor used in the Dual System Estimate of True Population United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Addis Ababa, Ethiopia, 14-18 September 2009 4

Some definitions Non-movers: persons who were in a particular household as of the census and PES date Out-movers: persons who were in a particular household at the census date but moved out or were not part of the household at the time of the PES In-movers: Persons who were enumerated in a particular household during the PES but where not there during the census date United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Addis Ababa, Ethiopia, 14-18 September 2009 5

Census date PES date Mary Paul John Mary Paul Peggy Peggy John United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Addis Ababa, Ethiopia, 14-18 September 2009

Census date PES date Mary Paul John Mary Paul Peggy Peggy John Non movers Mary Paul John Mary Paul Peggy In mover Out mover Peggy John United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Addis Ababa, Ethiopia, 14-18 September 2009

Measuring Omissions & Erroneous Counts Procedure A Constructs households as they existed at the time of the census Respondents asked to identify all persons in sample households on census date Persons are subsequently matched against names, addresses or locations on census records Estimates are then made of numbers and percent of matched non-movers and out-movers United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Addis Ababa, Ethiopia, 14-18 September 2009 8

Census date Procedure A PES date Mary Paul …John Mary Paul John Mary Paul Peggy Peggy John United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Addis Ababa, Ethiopia, 14-18 September 2009

Measuring Omissions & Erroneous Counts (contd.) Procedure B Identified all current residents in sample households at the time of PES Respondent asked to provide address(es) or location(s) where they were on census date Then matched against names on corresponding census questionnaires Estimates of number and per cent matched for non-movers and in-movers are calculated United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Addis Ababa, Ethiopia, 14-18 September 2009 10

Census date Procedure B PES date Mary, Paul Peggy Mary Paul John Mary Paul Peggy Peggy John United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Addis Ababa, Ethiopia, 14-18 September 2009

Measuring Omissions & Erroneous Counts (contd.) Procedure C Identifies all current residents living at the same address at the time of PES Also identifies persons who lived at the sample address during the census date Only census date residents (non-movers and out-movers) are, however, matched with census records Estimates are calculated of non-movers, out-movers, in-movers, of the per cent matched for non-movers & out-movers Procedure C is a combination of procedures A & B United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Addis Ababa, Ethiopia, 14-18 September 2009 12

Census date Procedure C PES date Mary, Paul Peggy …John Mary Paul John Mary Paul Peggy Peggy John United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Addis Ababa, Ethiopia, 14-18 September 2009

Strengths and Weaknesses of Procedure A Advantages Matching of non-movers and out-movers relatively simple and inexpensive – searches limited to sample areas and their adjacent areas Limitations Out-movers no longer at the sample address Getting information from proxy respondents difficult especially where the whole household moved Susceptible to underestimation of out-movers and omissions United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Addis Ababa, Ethiopia, 14-18 September 2009 14

Strengths & Weaknesses of Procedure B Advantages Field procedures simpler Provides better estimates of movers Limitations Higher cost of matching as it involves in-movers being identified within areas where they were during the census The above may result in extended matching because clusters (EAs) may not be in PES sample – more of a problem where addresses are lacking or inadequate Not sure whether failure to match means an actually omitted person or incorrectly located United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Addis Ababa, Ethiopia, 14-18 September 2009 15

Strengths and Weaknesses of Procedure C Advantages Method takes advantage of strengths of both procedures A & B Reduced matching difficulties Improved estimation of movers Limitation Relatively expensive, requires enumeration of in-movers, out-movers and non-movers United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Addis Ababa, Ethiopia, 14-18 September 2009 16

Thank You! United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys, Addis Ababa, Ethiopia, 14-18 September 2009