1. Household Surveys: American Community Survey & American Housing Survey Warren A. Brown February 8, 2007

2. Outline Purpose Target Population Sampling Frame Data Collection Non-Response Missing Data Weighting Sampling Error Access to Reports …to Aggregate Data …to Microdata Research Questions

3. ACS: Purpose Key Component for Re-Engineered Census Replacing the Decennial Census “Long-Form” Continuous measurement rather than snapshot Meet federal legislative and program needs Other stakeholders in state and local government and private sectors Provide annual data on demographic, social, economic and housing characteristics. Proportions rather than counts

4. ACS: Target Population Current residence not “Usual Residence” –“two-month rule” Household population in 2005 Total (HH + GQ) in 2006 and …. GQ residency is “de facto”

5. ACS: Sampling Frame Master Address File (MAF) –Official inventory of known living quarters –Linked to TIGER Housing Units –Based on Census 2000 MAF and updates from the USPS’ Delivery Sequence File Group Quarters –… and updates from the administrative records and the FSCPE –Excluded from ACS are domestic violence shelters, soup kitchens, commercial maritime vessels,…

6. ACS: Design of the Sample Annual Sample Size of 3 million addresses Series of Monthly Samples of 250,000 addresses HU sample in each of the 3,141 Counties Areas with smaller populations sampled at higher rates than those with larger populations HU Address sampling rate set by Block based on entity (municipality, school district, tract) Final sampling rate varies between 1.6% and 10% No HU address can be sampled more than once in 5 years

7. ACS: Sample Design cntd GQ facilities sample for each state Two stratum –Small (15 or fewer residents) –Large ( more than 15 residents) Small –Data collected on all residents –Facility eligible once in 5 years Large –Groups of ten residents sub-sampled –Number of groups determined by size of facility –Facility eligible every year

8. ACS: Data Collection HU addresses by three modes –Mailout of paper questionnaire in 1 st month –Telephone (CATI) non-response follow-up in 2 nd month –Personal visit (CAPI) non-response follow-up in 3 rd month to a sub-sample GQ –Personal visit within 6 weeks of sample selection

9. Data Collection Timetable

10. ACS: Questionnaire Content designed to meet the needs of federal government agencies 25 housing and 42 population questions (6 basic and 36 detailed) Household Respondent provides responses for all other residents of the household Householder or Reference Person is “Person 1”

11. ACS: Response Rates Participation is mandatory Sample addresses eligible for interviewing: –51% Mail response – 9% CATI non-response follow-up –38% CAPI non-response follow-up – 2% Non-interview

12. ACS: Missing Data Item non-response or failed edit check FEFU – failed-edit follow-up –More than 5 household members –Critical questions not answered –33% of mail return questionnaires in 2005 Imputation –Assignment used other data on respondent –Allocation – hot deck procedure –Flags variables

13. ACS: Weighting Person and Housing Unit weights Three stages –Probability of selection (initial sampling rate) –Adjust for non-response –Control to Intercensal Population Estimates Sum the weights –Person weights for person characteristics –HU weights for family, household or housing unit characteristics Householders = Households ???

14. ACS: Weighty Issues ACS 2005 for United States 288,378,137 Persons in Households 111,090,617 Households 114,763,475 Householders Average Household Size –2.60 based on Households –2.51 based on Householders

15. ACS: Sampling Error Publishing margins of error in tables More sample less error 1, 3, and 5 year estimates and associated sampling error Sampling error for small area data

16. Access to Reports/Tables/Data ACS section of Census.gov American FactFinder ACS FTP Site ACS Data Tables ACS Public Use Microdata

17. www.census.gov/acs/www/

18. American Community Survey Program Schedule ACS Demonstration Period: 1996-2004 –2000-2004 data products: Summer, 2005 ACS full implementation began January 2005 –First full implementation data products: Summer, 2006 –Annually updated data products every year thereafter

19. Full Implementation 3 million addresses every year throughout the U.S. and in Puerto Rico Provide annual profiles for communities of 65,000 or more Provide 3- to 5-year cumulations for communities of less than 65,000 population

21. ACS Sample Design AvailableCollectionSample Now2004 Partial Household 20062005Full Household 20072006 Full Household & GQs

22. ACS “Long Form” Data by Geography AvailableGeographic Areas 2006County, Municipality > 65,000 2007County, Municipality > 65,000 2008County, Municipality > 20,000 2009County, Municipality > 20,000 2010All Municipalities, Tracts, BGs

23. ACS vs Traditional Census AvailableACSOld Census 2006>65,000N/A 2007>65,000N/A 2008>20,000N/A 2009>20,000N/A 2010ALLN/A 2011ALLN/A 2012ALL

24. ACS: Access to Aggregate Data Tabular data on American FactFinder Summary Files similar to SF3 being tested

25. ACS: Access to Microdata ACS 2005 PUMS on –American FactFinder –Data Ferrett Tabulated Estimates for User Verification ACS PUMS is a sub-sample representing 1% of total housing units

29. ACS: Research Questions