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) Housing Units
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 GQ
Mailout of paper questionnaire in 1st month
Telephone (CATI) non-response follow-up in 2nd month
Personal visit (CAPI) non-response follow-up in 3rd 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

18. American Community Survey Program Schedule
ACS Demonstration Period:
data products: Summer, 2005
ACS full implementation began January 2005
First full implementation data products: Summer, 2006
Annually updated data products every year thereafter
Testing of the American Community Survey methodology began in 1996 in four sites: Brevard County, FL; Rockland County, NY; Multnomah County, OR; and Fulton County, PA.
The number of ACS test sites was expanded to 31 in These sites were selected to represent a variety of conditions including—
Hard-to-enumerate areas: Bronx County, NY
Big cities: San Francisco, CA
Rural counties: Fulton County, PA
Geographic distribution throughout the U.S.
Each year between 2000 and 2004 the American Community Survey was sent to about 800,000 addresses in 1,203 counties.
This enabled the Census Bureau to release data every year for every state and the District of Columbia, more than 200 Congressional Districts, and most counties and cities with populations of 250,000 or more.
The demonstration period of the ACS ended in December 2004.
In January 2005 full implementation of the ACS began.
The first data products from the fully implemented ACS will be available in the summer of 2006.
Every year thereafter data products will be released from the ACS conducted during the previous calendar year.

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
In 2005 the American Community Survey expanded to a monthly sample of about 250,000 addresses throughout the U.S. and Puerto Rico.
Every county in the U.S. and municipio in Puerto Rico is included as well as all American Indian reservations, Alaska Native villages, and Hawaiian Home Lands.
In 2005 the annual sample of 3,000,000 addresses covered the population living in housing units. The group quarters population also was covered beginning in January 2006.
Data profiles will be available for communities of 65,000 or more beginning with the 2005 ACS, released in 2006.
Every year thereafter annual data will be released for communities of 65,000 or more in the year following the data collection.
Data for smaller communities will be available as 3-year and 5-year cumulations beginning in 2008 and 2010, respectively.
The 3-year and 5-year estimates also will updated every year.
See the next slide for an explanation.

20. 2000 through 2004 data from the testing and development phase of the ACS are available now for communities with populations of 250,000 or more.
Data for communities of 250,000 or more will continue to be released every year when the ACS is fully implemented.
Data from the 2005 ACS, the first year of full implementation, will be released in the summer of 2006 for communities with populations of 65,000 or more.
Every year thereafter annual data will be released in the summer following the year of data collection for communities of 65,000 or more.
There are nearly 7,000 communities of 65,000 or more compared to only about 850 with populations of 250,000 or more.
Three-year data, from the ACS, will be released in 2008 for communities of 20,000 or more.
Every year thereafter new three-year data will be released—in 2009 data from the ACS, in 2010 data from the ACS, etc.
Five-year data, from the ACS will be released in 2010 for communities smaller than 20,000.
The types of geographic areas for which data will be available are the same as those for which Census 2000 long-form data were released.
Five-year data will be available for geographic areas as small as census tracts. Some data will even be available for block groups.
Every year after 2010 new five-year data will be released—in 2011 data from the ACS, in 2012 data from the ACS, etc.
For large communities, with populations of 65,000 or more, one-year, three-year, and five-year data will be available every year beginning in 2010.

21. ACS Sample Design Available Collection Sample Now 2004
Partial Household
2006
2005
Full Household
2007
Full Household & GQs

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

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

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