american community survey overview
DESCRIPTION
American Community Survey Overview. Jerry Wong Information Services Specialist Los Angeles Regional Office U.S. Census Bureau. 1/10. What is the American Community Survey?. A large, continuous survey that: is sent to 3 million resident addresses per year - PowerPoint PPT PresentationTRANSCRIPT
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American Community Survey American Community Survey
OverviewOverview
Jerry WongJerry WongInformation Services SpecialistInformation Services Specialist
Los Angeles Regional OfficeLos Angeles Regional OfficeU.S. Census BureauU.S. Census Bureau
1/10
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What is the American Community What is the American Community Survey?Survey?
A large, continuous survey that:
– is sent to 3 million resident addresses per year
– produces characteristics of population and housing
– produces estimates for small areas and small population groups
– Produces characteristics, not a population count
– Key component of the decennial census program
History and Timeline of the ACSHistory and Timeline of the ACS
19811981
19991999
19901990
20092009
19941994
Continuous measurement conceptualized
Congress renewed interest in an alternative to the once-a-decade census
Work began on what evolved into the ACS
First operational test conducted in 4 sites
Test sites expanded yearly to 36 counties in 26 states
19951995
20052005
N=165,000 housing units
20002000
N=866,000 housing units in 1,239 counties
N=3,000,000 housing units in all counties in 50 states, DC & PR
Group Quarters added
20062006
First 1-yr estimates released for areas 65,000+
20082008
First 3-yr estimates released for areas 20,000+
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Developing the ACSDeveloping the ACS
The ACS was developed to:
1. Focus the Census on improving the population count
2. Provide characteristic data more than once every 10 years to frame policy issues
3. Allow use of current data to respond to new trends
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Decennial CensusDecennial Census
Census 2000 used 2 forms
1.“short” form – asked for basic demographic and housing information, such as age, sex, race, how many people lived in the housing unit, and if the housing unit was owned or rented by the resident
2.“long” form – collected the same information as the short form but also collected more in-depth information such as income, education, and language spoken at home
Only a small portion of the population, called a sample, received the long form.
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Census 2000 and ACSCensus 2000 and ACSSimilaritiesSimilarities
• Many questions similar
• Many of the same basic statistics are released
• Comparisons can be made for most population and housing subjects
• http://www.census.gov/acs/www/UseData/compACS.html
• 5-year estimates will be produced for same broad set of geographic areas
– including census tracts and block groups, zip code tabulation areas
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Census 2000 and ACSCensus 2000 and ACSKey DifferencesKey Differences
• ACS data now available for larger and mid-sized areas
• ACS data for small geographic areas and population groups will be produced every year starting in 2010
• ACS data describe a period of time and published data are based on 12 months, 36 months, or 60 months
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Census 2000 and ACSCensus 2000 and ACSData QualityData Quality
• Goal of the ACS: Produce data of comparable quality to Census 2000 long form
• ACS 5-year data– Sampling error is larger in ACS due to smaller
sample size– Non-sampling error is smaller due to:
• Lower rate of nonresponse• Higher item response rates• Permanent interviewing staff using automated data
collection
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2010 Census and the ACS2010 Census and the ACS
2010 Census ACS
• U.S. population count• U.S. population
characteristics
• Short form only• Includes short form
questions
• Only long form is for U.S. territories, except Puerto Rico
• Conducted in Puerto Rico
• “Usual residence” rule • “Current residence” rule
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American Community SurveyAmerican Community SurveyContentContent
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Social CharacteristicsSocial Characteristics
• Education• Marital Status• Fertility• Grandparent
Caregivers• Veterans• Disability • Status
• Place of Birth• Citizenship• Year of Entry• Language Spoken at Home• Ancestry/Tribal• Affiliation
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EEconomic Characteristicsconomic Characteristics
• Income• Benefits• Employment Status• Occupation• Industry• Commuting to Work• Place of Work
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Housing CharacteristicsHousing Characteristics
• Tenure (own vs. rent)• Occupancy & Structure• Housing Value• Taxes & Insurance• Utilities• Mortgage/Monthly Rent
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Demographic CharacteristicsDemographic Characteristics
• Sex• Age• Race• Hispanic Origin
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Recent Content ChangesRecent Content Changes
• New Content2008
1. Health Insurance Coverage
2. Veteran’s Service-connected Disability
3. Marital History
2009
1. Field of Undergraduate Degree
• Wording and format changes in 2008 to match Census 2010 questions
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2008 Content Changes2008 Content Changes
• Three new questions– Health Insurance Coverage– Veteran’s Service-connected Disability– Marital History
• Deletion of one question– Time and main reason for staying at the address
• Changes in some wording and format
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ACS Sample DesignACS Sample Design
• Sample is accumulated over TIME to produce lowest levels of geographic detail to replace census sample
• 5 years of data are required for areas and population groups with less than 20,000 population
• Sample cases selected from an updated Master Address File (MAF)
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SampleSample
• Questionnaires mailed to about 1 in 480 addresses each month throughout the U.S. and Puerto Rico.
• 1 in 40 addresses per year (2.5% of the population).
• Average of 500-600 addresses per month per congressional district.
• Total of 3 million addresses each year, or 250,000 per month.
• Inclusion of population in group quarters beginning in 2006.
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Target PopulationTarget Population
• Resident population of the United States and Puerto Rico
• Living in housing units and group quarters (group quarters added in 2006)
• Current residents at the selected address
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Methodology Methodology
• Sample includes about 3 million addresses each year
• Three modes of data collection– mail– phone– personal visit
• Data are collected continuously throughout the year
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OperationsOperations
Mail Telephone Personal Visit
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Period EstimatesPeriod Estimates
• Describe the average characteristics over a specific period of time
• Contrast with point-in-time estimates – Do not describe the characteristics on a
specific date
• Period is 1 year, 3 years, or 5 years for ACS
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Geographic BoundariesGeographic Boundaries
• Multiyear estimates are based on geographic boundaries as of January 1 of the last year in the multiyear period
Example: 2006-2008 ACS estimates use boundaries as of Jan 1, 2008
• Boundaries of other statistical areas will be updated every decade in conjunction with the decennial census
• 2010 Census boundaries will be used for data released in 2011
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ACS Data Release ScheduleACS Data Release ScheduleData Product Population Size Data released in:
of Area 2006 2007 2008 2009 2010 2011 2012
1-Year Estimates 65,000+ 2005 2006 2007 2008 2009 2010 2011for Data Collected in:
3-Year Estimates 20,000+ 2005-2007 2006-2008 2007-2009 2008-2010 2009-2011for Data Collected in:
5-Year Estimates All Areas* 2005-2009 2006-2010 2007-2011for Data Collected in:
Data Product Population Size Data released in: of Area 2006 2007 2008 2009 2010 2011 2012
1-Year Estimates 65,000+ 2005 2006 2007 2008 2009 2010 2011for Data Collected in:
3-Year Estimates 20,000+ 2005-2007 2006-2008 2007-2009 2008-2010 2009-2011for Data Collected in:
5-Year Estimates All Areas* 2005-2009 2006-2010 2007-2011for Data Collected in:
* Five-year estimates will be available for areas as small as census tracts and block groups.Source: US Census Bureau
Hypothetical situation: If Census 2010 contained a long form, detailed characteristic data would not be available until 2012
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ACS Data ProductsACS Data Products
Profiles– Data Profiles– Narrative Profiles– Comparison Profiles– Selected Population Profiles
Tables– Detailed Tables and Collapsed Tables– Subject Tables– Ranking Tables– Geographic Comparison Tables
Thematic Maps
Public Use Microdata Sample (PUMS) Files
ACS Data for Geographic Areas in HawaiiACS Data for Geographic Areas in Hawaii
Geography 2008 1-Year Data 65,000+ Population
2006-2008 3-Year Data 20,000+ Population
State Hawaii Hawaii
Hawaii; In various metro or micropolitan statistic areas
Hawaii; Urban
Hawaii; Rural
County Hawaii County
Honolulu County
Maui County
Hawaii County
Honolulu County
Maui County
Kauai County
Place Honolulu CDP Honolulu CDP
Hilo CDP
Kahului CDP
Kailua CDP
Kaneohe CDP
Kihei CDP
Mililani Town CDP
Pearl City CDP
Waimalu CDP
Waipahu CDP
School District Hawaii Department of Education Hawaii Department of Education
ACS Data for Geographic Areas in Hawaii ACS Data for Geographic Areas in Hawaii
Geography 2008 1-Year Data 65,000+ Population
2006-2008 3-Year Data 20,000+ Population
Metropolitan or Micropolitan Statistical Area
Hilo, HI Micropolitan Statistical Area
Honolulu Metropolitan Statistical Area
Kahului-Wailuku, HI Micropolitan Statistical Area
Hilo, HI Micropolitan Statistical Area
Honolulu Metropolitan Statistical Area
Kahului-Wailuku, HI Micropolitan Statistical Area
Kapaa, HI Micropolitan Statistical Area
Urban Area Honolulu, HI Urbanized Area
Kailua (Honolulu Co.)—Kaneohe, HI Urbanized Area
Honolulu, HI Urbanized Area
Kailua (Honolulu Co.)--Kaneohe, HI Urbanized Area
Hilo, HI Urban Cluster
Kahului HI Urban Cluster
Kailua (Hawaii Co.)--Holualoa, HI Urban Cluster
Kihei, HI Urban Cluster
Pukalani—Makawao—Haiku—Pauwela, HI Urban Cluster
Congressional District
Congressional District 1
Congressional District 2
Congressional District 1
Congressional District 2
Public Use Microdata Area (PUMA)
PUMA5 00100, PUMA5 00200, PUMA5 00301, PUMA5 00302, PUMA5 00303, PUMA5 00304, PUMA5 00305, PUMA5 00306, PUMA5 00307
PUMA5 00100, PUMA5 00200, PUMA5 00301, PUMA5 00302, PUMA5 00303, PUMA5 00304, PUMA5 00305, PUMA5 00306, PUMA5 00307
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Using the Data:Using the Data:Factors to ConsiderFactors to Consider
• Universe and residence rules
• Time Periods
• Reference Periods
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Residence RulesResidence Rules
• The American Community Survey uses a “two-month” rule
• Decennial census based upon the concept of “usual residence”
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Residence RulesResidence Rules
• Resident of a housing unit if a person: - Lives there year round - Lives there more than 2 months but not year round - Is living there now with no other place to live - Is away now for 2 months or less
• Not a resident of a housing unit if a person:
- Lives there 2 months or less with another residence - Is away now for more than 2 months
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Period EstimatesPeriod Estimates
• Describes the characteristics of an area over a specific period of time
• Contrasts with point-in-time estimates that describe the characteristics of an area on a specific date
• 1-year, 3-year, and 5-year estimates are released for geographic areas that meet specific population thresholds
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Reference PeriodsReference Periods
ACS uses the ACS uses the interview dateinterview date as the as the single reference point, or as the end ofsingle reference point, or as the end of a reference period, for all data collectiona reference period, for all data collection ..
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Questions With No Specific Reference PeriodQuestions With No Specific Reference Period
• Most ACS questions• do not stipulate a• period of time that• should be referenced
• Interpretation is yearly• average since the• data are collected• each month and • averaged across months
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Questions With a Specific Reference Period Questions With a Specific Reference Period Relative to Interview DateRelative to Interview Date
• Other questions specify a period of time relative to the date of interview
• Interpretation is still a yearly average but covering a slightly different period of time than the calendar year
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Group QuartersGroup Quarters
• Place where people live or stay that is normally owned or managed by an entity or organization providing housing or services for the residents. Two types of group quarters:Two types of group quarters: 1. Institutional 1. Institutional 2. Non-institutional2. Non-institutional
• Group Quarters Population includes all people notGroup Quarters Population includes all people not living in households.living in households. -- This term includes those people residing in group quarters as of the date the ACS was conducted..
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Overview of ACS TimelineOverview of ACS Timeline
• First year of data collection for full sample in 2005.• Data for calendar year 2007 released beginning in
August 2008.• Annual data for geographic areas over 65,000
population.• 3 year averages are now available for geographic
areas 20,000 to 65,000.• 5 year averages for geographic areas under
20,000 in 2010.
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TimelineTimeline
• ACS Data single year collection (e.g. 2007) is closed out just after the beginning of a calendar year (e.g. 2008)
• Single-year and multiyear data products start to become available in the summer of the same year.
• For example 2007 ACS estimates were released in 2008
• The cycle repeats EVERY year
Release Schedule for ACS DataRelease Schedule for ACS Data
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Understanding Estimates Understanding Estimates and and
Margin of ErrorMargin of Error
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EstimatesEstimates
• ACS data are estimates
• ACS data are not counts of the population or housing
• Population counts are produced from the decennial census
- Counts are updated throughout the decade through the Population Estimates Program
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Margin of Error (MOE)Margin of Error (MOE)
• Margin of Error Definition:Margin of Error Definition:
A measure of the precision of an estimate at a given A measure of the precision of an estimate at a given level of confidence (90%, 95%, 99%)level of confidence (90%, 95%, 99%)– MOEs at the 90% confidence level for all MOEs at the 90% confidence level for all
published ACS estimatespublished ACS estimates
• Confidence Interval Definition:Confidence Interval Definition:
A range that is expected to contain the population A range that is expected to contain the population value of the characteristic with a known probability.value of the characteristic with a known probability.
Margin of ErrorMargin of Error
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Interpreting Margin of ErrorInterpreting Margin of Error
• Indicates that a data user can be 90 percent certain that the estimate and the population value differ by no more than the value of the MOE
• MOE can help data users assess the reliability of an estimate
• MOE can help data users avoid misinterpreting small differences between estimates as significant
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American Community Survey: American Community Survey: Multiyear DataMultiyear Data
20082006 2007
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Population Thresholds for Population Thresholds for ACS EstimatesACS Estimates
1-year estimates
3-year estimates
5-year estimates
65,000 + people X X X
20,000+ people X X
Less than 20,000 people
X
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Constructing Multiyear EstimatesConstructing Multiyear Estimates
• Data are pooled across 36 or 60 months
• Data are weighted to produce estimates
• Estimates are controlled for age, sex, race, and Hispanic origin
• Multiyear estimates are not an average of 1-year estimates
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Use Multiyear Estimates When …Use Multiyear Estimates When …
• No 1-year estimate is available
• Margins of error for 1-year estimates are larger than required
• Analyzing data for small population groups
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Currency vs. ReliabilityCurrency vs. Reliability
Currency Reliability
1-year estimates provide information based on the last year
Larger sample sizes produce estimates that are more statistically reliable
3-year estimates provide information based on the last year and the 2 years before that
3-year estimates are based on 3 times as many sample cases as 1-year estimates
5-year estimates provide information based on the last year and the 4 years prior
5-year estimates are based on 5 times as many sample cases as 1-year estimates
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Inflation AdjustmentInflation Adjustment
• Dollar-valued data items are inflation adjusted to Dollar-valued data items are inflation adjusted to the most recent year for the period the most recent year for the period
• Income, rent, home value, and energy costsIncome, rent, home value, and energy costs
• Adjusted using inflation factors based on the Adjusted using inflation factors based on the Consumer Price Index (CPI)Consumer Price Index (CPI)
• Adjustment designed to put the data into dollars Adjustment designed to put the data into dollars with equal purchasing powerwith equal purchasing power
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Geographic BoundariesGeographic Boundaries
• Multiyear estimates are based on geographic Multiyear estimates are based on geographic boundaries as of January 1 of the last year in the boundaries as of January 1 of the last year in the multiyear periodmultiyear period
• Boundary Annexation Survey collects boundary Boundary Annexation Survey collects boundary changeschanges
• Boundaries of other statistical areas will be Boundaries of other statistical areas will be updated every decade in conjunction with the updated every decade in conjunction with the decennial censusdecennial census
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Population Controls
• Estimates of housing units and people are Estimates of housing units and people are controlled to the population estimates derived controlled to the population estimates derived from the Population Estimates Program from the Population Estimates Program
• Multiyear estimates are controlled to the average Multiyear estimates are controlled to the average of the individual year’s estimates for the periodof the individual year’s estimates for the period
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Using multiyear Estimates Using multiyear Estimates to Make Comparisons? to Make Comparisons?
Comparing Across GeographiesComparing Across Geographies
• Only compare the same type of estimate
• 1-year estimates to other 1-year estimates
• 3-year estimates to other 3-year estimates
• 5-year estimates to other 5-year estimates
• Same time period
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Comparing Across Time PeriodsComparing Across Time Periods
Same geographic areaSame geographic area– Use caution if geographic boundaries have
changed over time– Easier to compare non-overlapping periods– Make comparisons using the same length time
period
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Overlapping PeriodsOverlapping Periods
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American Community Survey American Community Survey Learning MoreLearning More
• ACS Main Page
• 2008 Data Release Page
• 2006-2008 Data Product Details
• Guidance on Comparing 2008 ACS 1-Year Data
• Guidance on Comparing 2006-2008 ACS 3-Year Data to Other Sources
• Geographic Overview
• User Notes
• Errata Sheets
• Design and Methodology Report
• The ACS Compass Products
American Community Survey American Community Survey Accessing Home PageAccessing Home Page
American Community SurveyAmerican Community SurveyACS Main PageACS Main Page
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American Community Survey American Community Survey 2008 Data Release2008 Data Release
http://www.census.gov/acs/www/Products/
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American Community Survey American Community Survey 2006-2008 Data Product Details2006-2008 Data Product Details
http://www.census.gov/acs/www/Products/users_guide/
American Community Survey American Community Survey 2006-2008 Data Product Details - Hawaii2006-2008 Data Product Details - Hawaii
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American Community Survey American Community Survey Geography OverviewGeography Overview
http://www.census.gov/acs/www/UseData/geo.htm
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American Community Survey American Community Survey Comparing 2008 ACS 1-Year DataComparing 2008 ACS 1-Year Data
http://www.census.gov/acs/www/UseData/compACS2008.htm
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American Community Survey American Community Survey Comparing 2006-2008 ACS 3-YearComparing 2006-2008 ACS 3-Year
http://www.census.gov/acs/www/UseData/compACS2006-2008.htm
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American Community Survey American Community Survey User NotesUser Notes
http://www.census.gov/acs/www/UseData/usernotes.htm
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American Community Survey American Community Survey
Errata Errata
http://www.census.gov/acs/www/UseData/Errata.htm
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American Community Survey American Community Survey Subject DefinitionsSubject Definitions
http://www.census.gov/acs/www/UseData/Def.htm
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American Community Survey American Community Survey Using Multiyear EstimatesUsing Multiyear Estimates
http://www.census.gov/acs/www/UseData/myeoverview.html
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American Community Survey American Community Survey Question by Question Fact SheetQuestion by Question Fact Sheet
http://www.census.gov/acs/www/SBasics/SQuest/factsheet.htm
American Community Survey American Community Survey Question by Question Fact Sheet Question by Question Fact Sheet
Health InsuranceHealth Insurance
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American Community Survey American Community Survey Design and Methodology ReportDesign and Methodology Report
Important reference document covering methods used in producing ACS data
Available at http://www.census.gov/acs/www/SBasics/desgn_meth.htm
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The ACS Compass ProductsThe ACS Compass ProductsA Compass for Understanding and Using American A Compass for Understanding and Using American
Community Survey DataCommunity Survey Data
• General Data Users• Businesses• High School Teachers• Congress• Federal Agencies• Media • PUMS• State and Local
Governments• Puerto Rico Community
Survey (PRCS)
• Researchers• Rural Areas• American Indian and
Alaska Native Populations
Planned
• Puerto Rico Community Survey (PRCS) – in Spanish
http://www.census.gov/acs/www/UseData/Compass/compass_series.html
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The ACS Compass ProductsThe ACS Compass ProductsA Compass for Understanding and Using American A Compass for Understanding and Using American
Community Survey DataCommunity Survey Data
• Fully scripted PowerPoint presentations
– An Overview of the ACS
– Things that May Affect the Estimates
– Understanding Multiyear Estimates
– Data Products
– Geographic Areas and Concepts
– Introduction to the PUMS files
• E-learning ACS Tutorial (forthcoming)
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For more informationFor more information
Subscribe to “ACS Alert”http://www.census.gov/acs/www/Special/Alerts.htm
Visit the ACS/PRCS website:http://www.census.gov/acs/www
Contact by telephone:301-763-1405
Contact by email:[email protected]
747474
U.S. Census BureauU.S. Census BureauPartnership & Data Services ProgramPartnership & Data Services Program
15350 Sherman Way, Suite 40015350 Sherman Way, Suite 400Van Nuys, CA 91406Van Nuys, CA 91406
(888) 806-6389 Toll Free(888) 806-6389 Toll Free
L.A. Regional Website: www.census.gov/losangelesL.A. Regional Website: www.census.gov/losangeles [email protected]@census.gov
[email protected]@census.gov
Resources: Need Assistance?Resources: Need Assistance?