June 15, 2023: The U.S. Census Bureau today released the Noisy Measurement File for the 2020 Census Redistricting Data (P.L. 94-171). 

Noisy Measurement Files (NMF) are an intermediate output of the Disclosure Avoidance System’s TopDown Algorithm (TDA). The TDA generates noisy measurements when it applies differentially private noise to each of the tabulations from the confidential data. Because the noise can result in internal and hierarchical inconsistencies within the tables we publish, the TDA completes a final step called “post-processing.” That post-processing improves accuracy for lower-level geographies and corrects those inconsistencies before the tables or Privacy-Protected Microdata Files are published.  

On June 30 we will release a separate NMF that applies the 2020 Disclosure Avoidance System (DAS) production settings to the 2010 Census tables from the former Summary File 1 (SF1) that now make up the new Demographic and Housing Characteristics File (DHC). In the May 25, 2023 newsletter, we incorrectly stated that file would be released concurrent with today’s 2020 NMF for the redistricting data.

Webinar June 15: Working with Noisy Measurement Files for the Redistricting and DHC Data Products 

Researchers interested in a deeper dive into accessing and using the NMFs to generate unbiased estimates and confidence intervals for the effect of disclosure avoidance on census data can join us for a webinar on Thursday, June 15.

Please save the date and log in information below:

• Date: June 15, 2023
• Time: 3:00 – 4:30 p.m. ET  
• WebEx link 
• Webinar/Access number (if needed): 2763 911 3394
• Webinar password (if needed): Census#1
• You can find recordings, transcripts, and slides for all disclosure avoidance webinars on the series webinar page.  

Related Links

• Noisy Measurement File for the 2020 Census Redistricting Data (P.L. 94-171)

• Webinar 6/15: Working with Noisy Measurement Files for the Redistricting and DHC Data Products