Investigation of Anomalies in Derived Variances for Estimates from The American Community Survey Public Use Microdata File

• Activity Number: 418
• Type: Topic Contributed
• Date/Time: Tuesday, August 6, 2013 : 2:00 PM to 3:50 PM
• Sponsor: Survey Research Methods Section
• Author(s): Sirius Fuller*+ and Karen E. King
• Companies: U.S. Census Bureau and U.S. Census Bureau
• Keywords: American Community Survey ; Public Use Microdata Sample ; Design Factors ; Design Effects

Abstract

The American Community Survey releases Public Use Microdata Sample (PUMS) files annually for users to calculate their own estimates. PUMS contains individual housing unit and person records for a limited set of geographic areas. Two methods exist for users to calculate Variances for estimates: a generalized variance method (design factor) and a replicate weight based method.

Research conducted outside of the Census Bureau has shown that the variance based on the replicate weight is much higher than the variance based on design factors for certain estimates at the national level. The Census Bureau is conducting research which will attempt to duplicate those findings and to look for possible causes of these results. It will look at the creation process for the replicate weights for PUMS records, focusing on the impact of PUMS sampling and weighting. It will examine the process to create design factors for PUMS data, focusing on the iterative linear regression used to create design factor candidates. This paper will show results and may offer some practical solutions to bring the two sets of SEs into better alignment.