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American Community Survey. Idaho State Data Center Boise September 7, 2005. What is the American Community Survey?. A large, continuous demographic survey Produces annual and multi-year estimates of the characteristics of the population and housing
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American Community Survey Idaho State Data Center Boise September 7, 2005
What is the American Community Survey? • A large, continuous demographic survey • Produces annual and multi-year estimates of the characteristics of the population and housing • Produces characteristics, not a population count • Produces information for small areas including tracts, block groups and population subgroups - updated every year • Key component of reengineered 2010 census
What is the American Community Survey? A program to provide annual and multi-year data for communities: • Age, gender, race/ethnicity • Families, children, elderly • Income, poverty • Work, unemployment • Housing • Education
Effects of the American Community Survey (ACS) on the 2010 Census • Eliminate long-form • Conduct a short form only census • Better knowledge of local areas • Ongoing contacts with local governments • Cost savings
How will the American Community Survey help your community? • Establish community goals • Compare your community with others • Identify community problems and solutions • Measure and publicize program results • Increase government accountability • Ensure fair funding distribution • Create community-specific programs • Locate facilities and programs
Expansion to Full ACS Sample • Testing and development: 1996-2004 • Full expansion began in 2005 • Group quarters delayed until 2006 • Annual national sample of about 3 million addresses • Provide profiles every year for communities of 65,000 or more • Provide 3- to 5-year cumulations for communities of less than 65,000 population
Comparing ACS with the Decennial Census Sample • How do the samples compare? • How does data collection compare? • What is the impact on the data?
How do the samples compare? Similarities • Systematic samples of MAF (Master Address File) addresses • Differential sampling rates for areas based on population size
How do the samples compare? Differences – ACS Sample Design • Initial sampling rate • about 2.5% each year • about 12.5% over 5-year period • Results in an initial sample of about • 250,000 addresses each month • 3 million addresses each year • 15 million addresses over 5-year period
How do the samples compare? Differences • ACS samples every year and spreads sample over 12 months; census samples once a decade and uses the entire sample at the same time • ACS subsamples for personal visit follow-up; court ruled against census subsampling • Census sample estimates based on about 18 million housing units; ACS 5 year estimates based on about 11 million housing units
How does data collection compare? Similarities • Primary method is self-response to a paper questionnaire • Content is the same
How does data collection compare? ACS data collection procedures: • Mail • Telephone • Personal visits • Use a current residence rule
How does data collection compare? Differences • ACS nonresponse follow-up uses computer-assisted telephone and computer-assisted personal interviews; past censuses have used only paper questionnaires • ACS data collected only from household members; census data often collected from neighbors • ACS interviews conducted by experienced and well-supervised staff; census enumerations conducted by inexperienced temporary workforce
What is the impact on the data? • ACS estimates have higher sampling error • measures are released for each estimate and shown as 90% confidence limits or margins of error in every table • Similar sampling error measures for census long form sample estimates have not been provided
What is the impact on the data? • ACS estimates have lower potential nonsampling error • Unit nonresponse: no data for a case • Item nonresponse: data missing for an item • These and other measures are released on ACS’s Quality Measures website www.census.gov/acs/www/UseData/sse/index.htm
Multi-year Estimation • Most multi-year estimates are generated by computing an average based on combining each years’ estimates • Estimates are computed using the geography in place as of the most recent year of the period • Dollar valued data items are inflation adjusted to most recent year of the period
Multi-year Estimation: Medians • Medians are produced using combined data records from all years, not by averaging each year’s median • A 3-year median household income estimate is determined by combining the household records from the 3 years into one data set and determining the median from this combined distribution
Multi-year Estimates • Example • Item with year-to-year increases and decreases • Overview only • Focus is on the timing and creation of 3-year and 5-year data products
ACS Data Products • Data Profiles • Multi-Year Profiles • Narrative Profiles • Expanded Ranking Tables • Redesigned and expanded Detailed Tables/Base Tables • Public Use Microdata Sample Files (PUMS) • New: Subject Tables • New: Selected Population Profiles • New: Thematic Maps
ACS Data Products American FactFinderhttp://factfinder.census.gov
Outreach and Education Materials • State and local handbook • National and community organizations handbook • Congressional toolkit • American Indian/Alaska Native toolkit • ACS Data User Guide (Fall 2005)
Information about the American Community Survey www.census.gov/acs/www
For More Information American Community Survey Web site(www.census.gov/acs/www) Call us at:1-888-456-7215 E-mail us at:cmo.acs@census.gov Subscribe to the ACS Alert
U. S. Census BureauSeattle Regional Office Partnership and Data Services Cam McIntosh, Information Specialist U.S. Census Bureau 700 Fifth Avenue, Suite 5100 Seattle, WA 98104 cam.mcintosh@census.gov 800-233-3308 206-553-5836