Presentation Transcript

1. An Overview of the American Community Survey

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2. Overview What is the American Community Survey? Content Survey Methodology Data Products How is it different from Census 2000?
3. What is the American Community Survey? 3
4. Decennial Census In Census 2000, the census used 2 forms “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 “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 asample, received the long form. 4
5. 2010 Census and American Community Survey 2010 Census will focus on counting the U.S. population The sample data are now collected in the ACS Puerto Rico is the only U.S. territory where the ACS is conducted 2010 Census will have a long form for U.S. territories such as Guam and U.S. Virgin Islands Same “short form” questions on the ACS 5
6. American Community SurveyContent 6
7. American Community Survey Social Characteristics Education Marital Status Fertility Grandparent Caregivers Veterans Disability Status 7
8. American Community Survey Economic Characteristics Income Benefits Employment Status Occupation Industry Commuting to Work Place of Work 8
9. American Community Survey Housing Characteristics Tenure Occupancy & Structure Housing Value Taxes & Insurance Utilities Mortgage/Monthly Rent 9
10. American Community Survey Demographic Characteristics Sex Age Race Hispanic Origin 10
11. American Community Survey 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 11
12. American Community SurveyTarget Population Resident population of the United States and Puerto Rico Living in housing units and group quarters Current residents at the selected address “Two month” rule 12
13. American Community SurveyGroup 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. 2 categories of group quarters: Institutional Non-institutional 13
14. American Community Survey Period Estimates ACS estimates are period estimates, describing the average characteristics over a specified period Contrast with point-in-time estimates that describe the characteristics of an area on a specific date 1-year, 3-year, and 5-year estimates will be released for geographic areas that meet specific population thresholds 14
15. American Community Survey Data Products Release Schedule * Five-year estimates will be available for areas as small as census tracts and block groups. Source: US Census Bureau 15
16. American Community SurveyData Products Profiles Data Profiles Narrative Profiles Comparison Profiles Selected Population Profiles Tables Detailed Tables Subject Tables Ranking Tables Geographic Comparison Tables Thematic Maps Public Use Microdata Sample (PUMS) Files
17. American Community Survey Learning More ACS Main Page 2007 Data Product Details Subject Definitions Guidance on Comparing 2007 Data to Other Sources Design and Methodology Report The ACS Compass Products 17
18. American Community SurveyACS Main Page http://www.census.gov/acs/www 18
19. American Community Survey 2007 Data Release http://www.census.gov/acs/www/Products/ 19
20. American Community Survey 2007 Data Product Details http://www.census.gov/acs/www/Products/users_guide/ 20
21. American Community Survey 2007 Data Product Details 21
22. American Community Survey Comparison Guidance Comparing 2008 ACS to 2007 ACS Census Bureau supports comparisons made between 2007 and 2008 ACS data Comparing 2008 ACS to Census 2000 Differences between the 2008 ACS and Census 2000 include residence rules, universes, and reference periods. 22
23. American Community Survey Comparing Data http://www.census.gov/acs/www/UseData/compACS.htm 23
24. Set of educational handbooks aimed at specific audiences Presentation slides on important ACS topics E-learning tutorial American Community Survey The ACS Compass Products 24
25. American Community SurveySimilarities with Census 2000 Same questions and many of the same basic statistics 5-year estimates will be produced for same broad set of geographic areas including census tracts and block groups 25
26. American Community SurveyKey Differences from Census 2000 Beginning in 2010, data for small geographic areas will be produced every year versus once every 10 years Data for larger areas are available now and data for mid sized area will be available in December 2008 Census 2000 data described the population and housing as of April 1, 2000 while ACS data describe a period of time and require data for 12 months, 36 months, or 60 months 26
27. American Community SurveyKey Differences from Census 2000 The goal of ACS is to produce data comparable to the Census 2000 long form data These estimates will cover the same small areas as Census 2000 but with smaller sample sizes Smaller sample sizes for 5-year ACS estimates results in reductions in the reliability of estimates 27

28. Geographic Areas and Concepts for the American Community Survey

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29. Overview of Session Basic Census Bureau geography Geographic areas for which ACS data are available 2007 1-year estimates 2005-2007 3-year estimates Geographic area concept and definition issues to be aware of when using ACS data
30. What is not covered? Small geographic areas that will only appear in 5-year products Block groups and census tracts Geography products, such as maps, shapefiles, and relationship files Geographic entity codes, such as FIPS codes
31. Census Geographic ConceptsLegal/Administrative and Statistical Areas
32. ACS Geographic Area Types U.S. and Puerto Rico
33. Hierarchy of Census Geographic Entities 33
34. Public Use Microdata Areas (PUMAs) Minimum population of 100,000 Cannot cross state boundaries Composed of: Census tracts Places One or more Counties Combination of Tracts and Counties 34
35. Public Use Microdata Areas
36. ACS Geographic Area Types U.S. and Puerto Rico
37. Understanding Multiyear Estimates from the American Community Survey
38. Overview What are multiyear estimates? When should you use multiyear estimates? What should you be aware of when using multiyear estimates? How can you use multiyear estimates to make comparisons? Example of using multiyear estimates
39. What are multiyear estimates?
40. What is a Period Estimate? Definition An estimate that describes the average characteristics of an area over a specific time period Period for ACS 1-year estimates is the calendar year Different from a point-in-time estimate
41. What is a Multiyear Estimate? Definition A period estimate that encompasses more than one calendar year Period for ACS multiyear estimates is either 3 or 5 calendar years
42. Population Thresholds for ACS Estimates
43. How to Label Multiyear Estimates ACS estimates based on data collected from 2005-2007 should not be labeled “2006” or “2007” estimates Multiyear estimates do not represent any one year or the midpoint of a period Correct labeling for multiyear estimate: “The child poverty rate for the 2005-2007 period was X percent.”
44. Constructing 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
45. When should I use multiyear estimates?
46. 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
47. Currency vs. Reliability
48. Reliability Note: Fictional data
49. What should I be aware of when using multiyear estimates?
50. Inflation Adjustment Dollar-valued data items are inflation adjusted to the most recent year for the period Income, rent, home value, and energy costs Adjusted using inflation factors based on the Consumer Price Index (CPI) Adjustment designed to put the data into dollars with equal purchasing power
51. Geographic Boundaries Multiyear estimates are based on geographic boundaries as of January 1 of the last year in the multiyear period Boundary Annexation Survey collects boundary changes Boundaries of other statistical areas will be updated every decade in conjunction with the decennial census
52. Geographic Boundaries Amarillo city, Texas
53. Population Controls Estimates of housing units and people are controlled to the population estimates derived from the Population Estimates Program Multiyear estimates are controlled to the average of the individual year’s estimates for the period
54. How can I use multiyear estimates to make comparisons?
55. Comparing 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
56. Counties in Kentucky, by Population Size Source: U.S. Census Bureau, American Community Survey Handbook for General Audiences.
57. Comparing Data in 2010
58. Comparing Across Time Periods Same 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
59. Overlapping Periods
60. Introduction to the Public Use Microdata Sample (PUMS) File from the American Community Survey
61. Overview What is the ACS Public Use Microdata Sample (PUMS) file? What geographic areas are available in the ACS PUMS? How does the Census Bureau protect confidentiality in the ACS PUMS? How do I access ACS PUMS data?
62. What is the ACS PUMS file? A sample of population and housing unit records from the American Community Survey Allows users to create custom tables that are not available through pretabulated ACS products The 1-year ACS PUMS file represents 1 percent of the U.S. population
63. Summary Data and Microdata What’s the Difference? Summary data are predefined tables for specific geographic areas (states, counties, etc.) In the ACS microdata, the basic unit is an individual housing unit or person
64. Who Should Use the ACS PUMS? People who want to create tables that are not available through American FactFinder People who need data for small or unique population groups People interested in mapping population and housing characteristics
65. Sample Questions That the ACS PUMS Could Answer What proportion of children ages 5 to 9 live in households that do not have telephone service? What is the veteran status of college students living in Maine? What proportion of low-income workers in Kentucky commute 90+ minutes to work?
66. Geographic Areas in the ACS PUMS Nation All states, D.C., Puerto Rico Public Use Microdata Areas (PUMAs)
67. What are PUMAs? Predefined areas with 100,000+ residents Combinations of adjacent counties and census tracts within states PUMA boundaries match those used in Census 2000, with exception of Louisiana
68. Identifying PUMAs PUMAs are identified by a five-digit number, unique within each state Geographic equivalency files show how other areas align with PUMA boundaries Located on the PUMS download page on American FactFinder: http://factfinder.census.gov/home/en/acs_pums_2007_3yr.html Census 2000 PUMAs will continue to be used until after the 2010 Census
69. Protecting Confidentiality in the ACS PUMS Title 13 requires the Census Bureau to keep all personal information strictly confidential: By stripping personal information from records Through “data swapping,” “top coding,” and “bottom coding” By including only a sample of ACS responses By limiting geographic areas on the PUMS
70. Accessing PUMS Files Data can be downloaded through FactFinder and analyzed with statistical software Or accessed through the menu-driven DataFerrett system Refer to PUMS data dictionary http://factfinder.census.gov/home/en/acs_pums_2007_1yr.html
71. Bedrooms Condominium status Contract rent (monthly rent) Cost of utilities and fuels Family income Family and household relationships Farm status and value Fire, hazard, and flood insurance Food Stamps Fuels used Gross rent House heating fuel Household income Household type Kitchen facilities Linguistic isolation Meals included in rent Mortgage status and owner costs Plumbing facilities Presence and age of own children Presence of subfamilies in household Property value Real estate taxes Residence state Rooms Telephone in housing unit Tenure Units in structure Vacancy status Vehicles available Year householder moved into unit Year structure built Housing Topics Covered in ACS PUMS
72. Military status and periods of service Mobility status Occupation Personal care limitation Place of birth Place of work Poverty status Race Relationship School enrollment and type of school Sex Time of departure for work Travel time to work Vehicle occupancy Weeks worked Work status Work limitation status Year of entry Person Topics Covered in ACS PUMS Ability to speak English Age Ancestry Citizenship Class of worker Disability status Educational attainment Fertility Hispanic origin Hours worked Income by type Industry Language spoken at home Last week work status Marital status Means of transportation to work Migration
73. Downloading ACS PUMS data American FactFinder
74. Downloading ACS PUMS data American FactFinder http://factfinder.census.gov/home/en/acs_pums_2007_3yr.html
75. Other PUMS Resources American FactFinder Values used in top- and bottom-coding the variables Detailed codes for ancestry, occupation, etc. Links to geographic equivalency files Accuracy of the PUMS and methods of calculating sampling error
76. Analyzing PUMS Data DataFerrett Can be used to extract PUMS data using a menu-driven system Need to register to use DataFerrett Download DataFerrett and install it on your computer
77. DataFerrett Website http://dataferrett.census.gov/
78. Availability of ACS PUMS Data Available each year beginning in 2000 2007 ACS 1-year PUMS released September 2008 2005-2007 ACS 3-year PUMS released January 2009
79. Other Sources for ACS Data Microdata Integrated Public Use Microdata Series (IPUMS) from Minnesota Population Center: www.ipums.org PDQ-Explore: www.pdq.com Aggregate Data Social Explorer: www.socialexplorer.com Brookings State of Metropolitan America: www.brookings.edu/metro/StateOfMetroAmerica/Map.aspx