1 American Community Survey Idaho State Data Center Boise September 7, 2005
Mar 26, 2015
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American Community Survey
Idaho State Data CenterBoise
September 7, 2005
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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
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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
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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
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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
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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
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American Community Survey Data Release Timetable
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Comparing ACS with the Decennial Census Sample
• How do the samples compare?
• How does data collection compare?
• What is the impact on the data?
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How do the samples compare?
Similarities• Systematic samples of MAF (Master Address
File) addresses• Differential sampling rates for areas based on
population size
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Sampling Rates
Governmental Unit Size:
Number of Occupied
Housing Units
Census 2000
Sampling Rates
ACS 5-year
Sampling Rates
0 - 200 50.0% 50.0%
201 - 800 50.0% ~35.0%
801 - 1200 25.0% ~17.5%
1201 - 2000 16.7% ~12.0%
Over 2000 12.5% ~8.5%
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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
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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
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How does data collection compare?
Similarities• Primary method is self-response to a paper
questionnaire• Content is the same
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How does data collection compare?
ACS data collection procedures:• Mail• Telephone• Personal visits
• Use a current residence rule
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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
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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
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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
1811
Unit Nonresponse
97.7--2002
96.7--2003
96.7--2001
95.191.22000
ACSCensus 2000 Sample
Response Rates (100-unit nr rate)
Unit Response
1912
Item Nonresponse
7.114.9Housing items - Followup
5.911.5Housing items - Mail
4.512.9Population items - Followup
8.18.7Population items - Mail
6.610.4All modes/ items
2000
ACS
Census 2000
Sample
Summary Allocation Rates(amount of data missing from
interviews)
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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
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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
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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
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Multi-year Estimates
Example 2: Item with year-to-year increases and decreases (Homeownership rates)
61.5%
55.6%
40.0%
44.3%
66.7%
52.0%
0%
10%
20%
30%
40%
50%
60%
70%
2005 2006 2007 2008 2009 2010
Year
Perc
en
t
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Example 1: Percent Foreign Born Population Areas with 65,000+ population
2005 2006 2007 2008 2009 2010
Single-year estimates 20.0 21.2 23.3 28.6 32.6 35.1
3-year estimates (2005 – 2007) 21.5
3-year estimates (2006 – 2008) 24.8
3-year estimates (2007 – 2009) 28.6
5-year estimates (2005 – 2009) 25.9
3-year estimates (2008 – 2010) 32.2
5-year estimates (2006 – 2010) 28.9
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Example 1: Percent Foreign Born Population Areas with population between 20,000 and 65,000
2005 2006 2007 2008 2009 2010
3-year estimates (2005 – 2007) 21.5
3-year estimates (2006 – 2008) 24.8
3-year estimates (2007 – 2009) 28.6
5-year estimates (2005 – 2009) 25.9
3-year estimates (2008 – 2010) 32.2
5-year estimates (2006 – 2010) 28.9
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Example 1: Percent Foreign Born Population Areas with less than 20,000 population
2005 2006 2007 2008 2009 2010
5-year estimates (2005 – 2009) 25.9
5-year estimates (2006 – 2010) 28.9
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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 FactFinder
http://factfinder.census.gov
American FactFinder
http://factfinder.census.gov
ACS Data Products
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Data Profiles
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Narrative Profile
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Multi-Year Profiles
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Ranking Tables
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Ranking Table(without statistical significance)
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Ranking Table (with statistical significance)
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Ranking Table (chart)
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Thematic Map
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Subject Table
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Selected Population Profile
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Detailed Table/Base Table
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2004 ACS Products by Geography Type
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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)
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Information about the American Community Survey
www.census.gov/acs/wwwwww.census.gov/acs/www
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Guide to the ACS Data Products
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For More Information
E-mail us at: [email protected] us at: [email protected]
American Community Survey Web site
(www.census.gov/acs/www)
American Community Survey Web site
(www.census.gov/acs/www)Call us at: 1-888-456-7215Call us at: 1-888-456-7215
Subscribe to the ACS AlertSubscribe to the ACS Alert
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U. S. Census BureauSeattle Regional OfficePartnership and Data Services
Cam McIntosh, Information Specialist
U.S. Census Bureau
700 Fifth Avenue, Suite 5100
Seattle, WA 98104
800-233-3308
206-553-5836