The American Community Survey (ACS) Lisa Neidert McCormick Specialized Training Institute October , 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 Improve response rate for census  No long-form  No intrusive questions on census

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

Senator Burris and the ACS  What is it? Is it a scam?

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

ACS Operations: Mixed Mode

Workloads and Costs by Mode

ACS is mandatory

Interpreting ACS data  Universe and Residence Rules  Time periods  Reference periods  Comparison Guidelines S.htm S.htm  ACS Compass Products 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  Census 2010 Residence rules:

Data Products: Annual  Tabular Profiles Narrative Subject Geographic Comparison Ranking Detailed

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 Allows for geographies of 20,000+  Summary data GQ population is estimated for 2005 Geographic boundary changes reflected for all years  Microdata Re-weight Index income

Microdata vs Tabular  Census Bureau website emphasizes tabular data American FactFinder CensusScope  Trend data; ready-to-use NHGIS  Historical data  Census tracts for the nation  Microdata access Census Bureau FTP site Data Ferrett IPUMS website

Embargo Access  Journalists can get early access to data via embargo policy gopolicy.html gopolicy.html  Experiences with embargoed data Paul, Bill, others?