1. American Community Survey Presented at the Meeting of the National Neighborhood Indicators Partnership Susan Schechter May 2010 1

2. 2 What I’ll Cover Introduction to the American Community Survey Census 2000 and ACS – Similarities and Differences Plans for the first release of ACS 5-year estimates

3. 3 Introduction to the ACS The 2010 Census will only collect critical data required of the full population The detailed demographic, social, economic, and housing data will now be collected and disseminated using the American Community Survey

4. 4 Introduction to the ACS While ACS content is similar to the Census 2000 long form, the design and methodology differ ACS data are collected continuously throughout the year and estimates are released once-a- year in the form of 1-year, 3-year, and 5-year aggregates

5. 5 Introduction to the ACS The ACS has a diverse set of data users including federal, state, and local governments, academia, media, and the private sector Uses range from a single estimate for a grant application or homework assignment to complex research using microdata files

6. 6 Census 2000 and ACS Similarities Census 2000 questions are on the ACS ACS produces many of the same tables and characteristics as Census 2000 Same broad set of geographic areas Same basic data dissemination vehicle – American FactFinder and same basic types of data products

7. 7 ACS Data Products Used in Census 2000 Detailed Tables Summary Files Data Profiles and Subject Tables (Similar to Quick Tables) Thematic Maps Geographic Comparison Tables Public Use Microdata Sample (PUMS) Files

8. 8 ACS Data Products Not Included in Census 2000 Narrative Profiles Ranking Tables Comparison Profiles Selected Population Profiles

9. 9 Census 2000 and ACS Key Differences ACS data are collected continuously and all ACS estimates are period estimates Estimates will be released every year rather than once-a-decade ACS estimates are released in the form of both single year and multiyear estimates ACS estimates have more sampling error

10. Period Estimates Describe the average characteristics over a specific period of time Contrast with point-in-time estimates –ACS estimates do not describe the characteristics as of a specific date Period is 1 year, 3 years, or 5 years for ACS 10

11. 11 ACS estimates will be released every year while census estimates were released only once-a-decade

12. 12 ACS estimates are released in the form of both single year and multiyear estimates based on the estimated population of the geographic area

13. ACS Data Release Schedule 13 Hypothetical situation: If Census 2010 contained a long form, detailed characteristic data would not be available until 2012

14. 14 Data Release Rules Estimated Population of Geographic Area Type of ACS Estimates Released 65,000 or more1-year, 3-year, and 5-year 20,000 to 64,9993-year, and 5-year Less than 20,0005-year

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18. 18 The ACS sample is smaller than the sample in Census 2000 which means that ACS estimates will include more sampling error

19. 19 Quality of ACS Estimates Recent research suggests that margins of error around ACS 5-year estimates will be about 1.75 times as large as those associated with the Census 2000 sample estimates Evaluations after Census 2000 demonstrated reductions in ACS nonsampling error relative to Census 2000

20. 20 ACS Displays Margins of Error

21. 21 Census 2000 and ACS Other Differences ACS includes a few revisions to question wording as compared with Census 2000 ACS has added several new questions that were not included in Census 2000 ACS reference periods and residence rules differ from those used in Census 2000

22. 22 Questions Added to the ACS Health Insurance Coverage Marital History Service-Connected Disability Status and Rating Field of Degree

23. 23 Residence Rules Both the census and the ACS describe the resident population (housing units and group quarters) in the United States and Puerto Rico Census 2000 - usual residence as of April 1, 2000 ACS – current residence as of interview date

24. 24 Reference Periods Census 2000 centers its count and age distributions on a reference date of April 1, 2000. Some questions have a reference period different than April 1. Data generally describe characteristics between March and June of 2000. The ACS collects all data using a reference date of the date of interview. Like Census 2000, some questions have reference periods. Given that interviews are spread fairly evenly across the year, the data describe the calendar year but there is an overlap for questions that include a 12 month reference period.

25. 25 Differences between the 2010 Census and the ACS The 2010 Census will count the population to support apportionment and redistricting The ACS will supplement this information with annually updated data on the characteristics of population and housing Plus, many of the same differences (residence rules, reference periods) when you compare Census 2000 long form data to ACS

26. 2009 ACS First release of ACS 5-year estimates –Data will be available for small areas Census tracts Block Groups –Will be based on data collected from 2005, 2006, 2007, 2008 and 2009 The 2009 ACS (1-year estimates) and the 2007-2009 ACS (3-year estimates) will also be released 26

27. Census 2000 Data Products from the Long Form Sample ProductReleased Summary File 3 (SF3)2002 - 2003 Summary File 4 (SF4)2003 American Indian and Alaska Native Summary File (AIAN SF) 2003 Public use microdata sample (PUMS) files 2003 27

28. ACS Data Products 1-Year and 3-Year Estimates ACS data products have included detailed tables, other summary products and PUMS files The geographic detail of SF3 as well as data comparable to the SF4 and the AIAN SF were not possible with 1-year and 3-year estimates 28

29. ACS 5-Year Estimates We plan to release the first ACS 5-year estimates this year The 5-year data products will be similar in many ways to the existing ACS products and to Census 2000 products Over time, we expect the specific set of data products to change as we receive input from users and evaluate usage 29

30. ACS 5-Year Estimates Release Restrictions Unlike the 1- and 3-year estimates, there will be no 5-year population thresholds and no table restrictions based on reliability Only restrictions will be to protect the confidentiality of the data Margins of error will be published with all ACS estimates 30

31. ACS 5-Year Estimates Set of Proposed Tables We will produce the ACS tables that are most comparable to those released in Census 2000 Summary File 3 We will also produce some tables that were not included in Census 2000 – new tables that were designed after Census 2000 31

32. ACS 5-Year Estimates Set of Proposed Tables Most proposed summary levels will receive a full set of 5-year tables regardless of size or type – exception is block groups Some tables have geographic restrictions similar to those in place for Census 2000 SF3 32

33. 2005-2009 ACS Data Products Planned Detailed tables Summary files Data profiles Narrative profiles Subject tables **No Selected Population Profiles for ACS 5-Year Data **No SF4, or AIAN SF Files for the first release. Geographic comparison tables Thematic maps PUMS files 33

34. ACS 5-Year Estimates Number of Geographic Summary Levels by Data Product Estimated number of geographic summary levels Detailed tables670K Data profiles180K Subject tables170K Geographic comparison tables, thematic maps 90K 34

35. ACS 5-Year Estimates Number of Tables Proposed for Release Estimated number of tables Summary levels other than block groups Block Groups* Detailed tables800330 Data profiles40 Subject tables600 Geographic comparison tables, thematic maps 900 * The total number of block groups is estimated to be about 210,000 35

36. ACS 5-Year Estimates Geographic Summary Levels Most, but not all, of the geographic summary levels in Census 2000 SF3 will be included in the first ACS 5-year release This includes tracts, block groups, geographic components, and geographic intersections 36

37. ACS 5-Year Estimates Data Product Limitations by Geographic Summary Level For proposed geographic summary levels, we will always produce detailed tables We will only produce data and narrative profiles, subject tables and geographic comparison tables for a subset 37

38. ACS 5-Year Estimates Examples of 5-year Geographic Summary Levels for US and Puerto Rico Residence-based tabulations Estimated number of areas 1-year3-year5-year Congressional districts 435 Counties7851,0303,221 Tracts00~66,000 Block groups00~ 210,000 All summary levels~ 6,500~ 13,500~ 670,000 38

39. ACS 5-year Estimates Data Dissemination Plan We plan to release 5-year estimates annually and disseminate all 5-year ACS data products through the American FactFinder We plan to release census block group data only in a summary file format, accessible from the American FactFinder download center 39

40. ACS 5-Year Estimates Tentative Data Release Schedule Type of estimateRelease date 2009 ACS 1-year estimates Sept 2010 2007-2009 ACS 3-year estimates Dec 2010 or later, after the release of the 5-year estimates 2005-2009 ACS 5-year estimates Nov or Dec 2010, some data products released in 2011 40

41. ACS 5-Year Estimates Future Products We are evaluating the disclosure avoidance issues related to producing annual 5-year PUMS files. We plan to release the ACS SF4 and the ACS AIAN SF in 2012 based on the 2006-2010 ACS 5-year estimates 41

42. ACS 5-Year Estimates Future Products We expect to refine this plan for future releases and value your feedback on shortcomings or overkill We will continue to look for the most effective way to release 3 sets of ACS estimates annually along with the production of SF3, SF4, and AIAN SF-like products and PUMS files 42

43. 43 For 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: acso.users.support@census.gov