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

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

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

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”

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,…

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

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

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

Data Collection Timetable

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”

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

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

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 ???

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

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

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

www.census.gov/acs/www/

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 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 1999. 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.

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.

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 2005-2007 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 2006-2008 ACS, in 2010 data from the 2007-2009 ACS, etc. Five-year data, from the 2005-2009 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 2006-2010 ACS, in 2012 data from the 2007-2011 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.

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

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

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

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

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

ACS: Research Questions