Coverage improvement

1. Update on the Coverage Improvement Program for the 2010 CensusDave Sheppard Decennial Statistical Studies DivisionCensus Information Center Program October 9-11, 2007

2. Coverage improvement • Many operations or aspects of programs may lead to improved coverage in the Census • We’ll focus on two of them today…

3. Some plans to improve coverage for the 2010 Census • Review and possibly revise census enumeration residence rules and how we communicate these rules to respondents. • Determine ways to identify households with within-household coverage error and then develop and test methods to reduce the error. • In addition, Census Bureau staff will also provide an update on plans for measuring coverage error in Census 2010.

4. Some major coverage improvement topics not covered today: • Improve housing unit coverage by identifying the best methods for keeping the Master Address File (MAF) up to date • Develop methods for identifying the duplication of persons and housing units in the census

5. Coverage? • Coverage Improvement • Methods to address census error • Impacts census counts of people and housing units • Coverage Measurement • Evaluates the error in the Census • Does not change census counts

6. How do we end up with everyone* counted only once and in the right place? * or at least as many people as possible

7. 2010 Census coverage improvementresearch - two approaches • Get it right the first time • Help respondents to initially include the correct people on their Census form • Fix it later • Identify households with coverage problems, get back in touch with them, and make corrections

8. To get it right the first time … • Improve residence rules instructions to respondents • Self response paper forms • Enumerator wording for roster building • Simplify residence rules • Review of rules from Census 2000

9. To fix it later, we identify households … • We identify households with potential coverage problems because: • They missed counting someone (omissions), or • They counted someone who should not have been counted there (erroneous enumerations)

10. … for specific reasons • Identify omissions • Count discrepancies (low person count) • Use of undercount coverage question • Use of administrative records • Identify erroneous enumerations • Count discrepancies (high person count) • Use of overcount coverage question • Use of unduplication within the census • For both omissions & erroneous enumerations • Large households

11. The CFU Interview • Verify the household and the validate the address • Review the list of people reported in the initial enumeration • Update the roster • Remove anyone who is unknown • Add anyone who is missing • Ask questions about possible living situations for each person on the updated roster • Collect any missing demographic information

12. Past  Present • Census 2000 – About 2% of all households • Large households (LHH) • Count discrepancies (CD) • 2010 research – LHH/CD and ??? • Undercount coverage question • Overcount coverage question • Use of administrative record matching • Use of person matching to identify duplication • Coverage Followup • Field Verification`

13. Large households (LHH) • Household contains more people than fit on the form • Mailback cases with 7 or more people • Conducts CFU interview to: • Improve coverage • Collect demographics for persons 7+

14. Count discrepancies High data defined person discrepancies (HDDP) • Reported more people than the reported POP count on the census return Low data defined person discrepancies (LDDP) • Reported fewer people than the reported POP count on the census return

15. Count discrepancies (cont.) • Conduct CFU interview to improve coverage • Even if no one is added or deleted, we still determine the correct HH size

16. Undercount coverage question • Asked once at the household-level • Directly after question 1 about household size • To identify housing units with potential omissions • Probes include types of people historically missed in the Census

17. Undercount coverage question for the 2008 Dress Rehearsal

18. Overcount coverage question • Asked once for each of the first six people listed on the form • To identify housing units with potential erroneous enumerations • Probes include places where people are historically overcounted in the Census

19. Overcount coverage question for the 2008 Dress Rehearsal

20. Use of administrative records • First time we used this methodology was in the 2005 NCT, then in the 2006 Census test • Returns identified that contain fewer people than the administrative records database has for that address • Designed only to identify potential omissions

21. Use of person matching to identify duplication • Research from Census 2000 continued this decade • Identifies both potential person and housing unit duplication • Resolution through Coverage Followup or Field Verification

22. Residence Rules Instructions One little box … so many rules

23. Residence rules instructions • Explains how to apply the Census Residence Rules on paper forms: • Three sets of bullets detailing • who to include • who not to include • how to count people without a permanent place to stay • A question about the number of people in the household

25. Ongoing & Future Research

26. Ongoing & future research for coverage followup • Streamline coverage followup selection criteria • Comparing efficiencies of all types of cases • Primary measure: Cost per change to a roster • Added people and deleted people • Additional consideration possibly given to other factors as well • Effects on differential undercount • Effect on net census error

27. Ongoing & future research (cont.) • Improve the coverage followup interview • Identification of cases through the use of administrative records • Identification of duplicates through person matching

28. Questions? Dave Sheppard david.w.sheppard@census.gov