The AmericanCommunity Survey (ACS)
Lisa Neidert
NPC Workshop: Analyzing Poverty and Socioeconomic Trends Using the American Community Survey
June 22 – June 26, 2009
What is the ACS?
A large, continuous survey Produces single and multiyear estimates of
the characteristics of the population and housing
Produces information for small areas including tracts, block groups and population subgroups
Key component of the decennial census program
Origins of the ACS
More timely data Operational reasons
Steadier funding Year-round Interviewing
Skilled interviewers instead of temps
Strengthen Decennial Census Improved census geography
Updated address files
ACS Implementation
Full implementation: 2005* Every county nationwide Products released in 2006 Annual updated data products released
every year thereafter
*Did not include group quarters in 2005
Interpreting ACS data
Universe and Residence Rules Time periods Reference periods
Comparison Guidelines http://www.census.gov/acs/www/UseData/compAC
S.htm
ACS Compass Products Appendices
ACS Universe
Total resident population of the United States
Group Quarters population added to the sample in 2006
Example Ann Arbor, MI, 2006: 112,371 Ann Arbor, MI, 2005: 98,743 Ann Arbor, MI, 2000: 114,024
Residence Rules
Resident of the housing unit if: 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 the housing unit if: Lives there 2 months or less with another
residence Is away now for more than 2 months
Reference Periods
ACS uses the interview data as the single reference point, or as the end of a reference period, for all data collection Interviewed in October 2006
Earnings reference period: October 1, 2005 – September 30, 2006
Data Products Annual
Microdata 1%
~1,300,000 housing records ~3,000,000 person records
Microdata are a sample of the ACS respondents Approximately 65 of 100 Confidentiality measure
Data Products Multi-year
Combines 3 years worth of data, with a few modifications to the underlying data
Summary data GQ population is estimated for 2005 Geographic boundary changes reflected for all
years
Microdata Re-weight Index income
Data Products: Multi-year
3-year: 2006 - 2008 Release dates: August 2009+
Multiyear Estimates Study 5-year; 3-year; 1-year For test communities only
34 counties
http://www.census.gov/acs/www/AdvMeth/Multi_Year_Estimates/overview.html#noteforusers