Data Quality and the ACS

Introduction to the ACS Aggregator

Lisa Neidert

January 18, 2012PSC Data WorkshopAnn Arbor, MI

Synopsis

Census long-form data were not as good as you thought

ACS data are worse

Collapse cells or combine geographies

Tool: ACS Aggregator [Beta]

ACS Data Quality Issues

Sample Size 1 in 8 instead of 1 in 6

Mixed Mode Non-response is a ~1 in 3 sample Uneven response across geography

Population Controls Only at state/county Long-form data had short-form

Geographic Variation in ACS mail response: by pseudo county (2006-2008)

Census Bureau Solutions

Increase sample size 3.4 million households

Re-distribute sample Small census tracts + Low response areas + Large census tracts; high response areas –

Research

Education

PSC ACS Aggregator

Helps users re-calibrate margins of error after combining geographies or collapsing cells

Statistical Review

Compass Series: Technical Appendix

ACS Aggregator

Practice Data

Seattle: Capitol Hill Neighborhood Table B11001

Combine Geographies

Enter Name, Estimate, MOE for all geographies

Collapse Cells

Enter Name, Estimate, MOE for each column Geographies will be repeated

Questions/Comments

E-mail lisan@umich.edu