The American Community Survey (ACS) Lisa Neidert NPC Workshop: Analyzing Poverty and Socioeconomic Trends Using the American Community Survey June 23 – June 27, 2008

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

More timely data  Mariel Boat Lift  Natural disasters

More timely data...  Communities  Populations

ACS Implementation  Demonstration Period

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

Data Release Timetable

Sample Specifics  3,000,000 addresses 250,000 a month

Interpreting ACS data  Universe and Residence Rules  Time periods  Reference periods  Comparison Guidelines compACS.htm

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  Tabular Detailed Subject Geographic Comparison Ranking  Microdata 1 percent  ~1,300,000 housing records  ~3,000,000 person records

Data Products: Multi-year  3-year: Release dates: August  Multiyear Estimates Study 5-year; 3-year; 1-year For test communities only  34 counties ates/overview.html#noteforusers

Microdata vs Tabular  Census Bureau website emphasizes tabular data via American FactFinder FTP is interface to microdata  Exceptions  Workshop Micro (65%) Tabular (35%)