April 3, 2023: The U.S. Census Bureau today released a suite of files based on 2010 Census results to help data users analyze the impact of the new 2020 Census Disclosure Avoidance System.

Dubbed the “2010 Demonstration Data Products Suite – Redistricting and DHC,” the files incorporate the final production settings chosen for both the 2020 Census Redistricting Data (Public Law 94-171) Summary File and the Demographic and Housing Characteristics File (DHC). 

We will conduct a webinar about the release on Thursday, April 6, 2023 (see log-in information below).

Today’s Release Includes the Following:  

• A new, combined, 2010 Demonstration Privacy-Protected Microdata File (PPMF) for the Redistricting Data and DHC.

The new PPMF applies the 2020 Disclosure Avoidance System (DAS) production settings to two 2010 Census products: the Redistricting Data (Public Law 94-171) Summary File and tables from the former Summary File 1 (SF1) that now make up the new DHC. In census terminology, “production” settings are the final settings chosen to produce the final data products. We’re regenerating the PPMF in this combined format to produce a full set of Noisy Measurement Files (see below).

PPMFs present the data as rows of privacy-protected individual records (called microdata) rather than the aggregated totals found in a table-based format. As with past PPMF releases, IPUMS National Historical GIS plans to convert the PPMFs into user-friendly table-format files. 

Both the redistricting file and DHC are protected with the differentially private TopDown Algorithm (TDA). The TDA was specifically designed to ensure that census blocks—the “building blocks” of census geographical units—aggregate with increasing relative accuracy. The redistricting data included in this version will differ slightly from the production settings 2010 Census redistricting demonstration data product released in August 2021 because this is a completely new run with the same production settings. Note that each independent run of the 2010 Census data through the TDA infuses different values of noise to protect against disclosure. 

• Detailed Summary Metrics for the new PPMF

The Detailed Summary Metrics quantify differences between the published 2010 Census data (protected with “swapping”) and the 2010 demonstration data (protected with the production settings for the formally private disclosure avoidance system). The Detailed Summary Metrics provide measures of differences for select subjects and geographies.  

• Noisy Measurement File for the Redistricting data

Noisy Measurement Files are the intermediate output of the Disclosure Avoidance System’s 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.” This corrects those inconsistencies before the tables or PPMFs are published. 

This public release gives researchers and data scientists the opportunity to independently process the files, complete analysis and conduct valuable assessments of the confidentiality protections.

Today’s release includes the 2010 Redistricting NMF only. We will release the 2010 DHC Noisy Measurement File separately in June.

• Supporting materials that describe the contents of the release

In addition to technical documentation for the PPMF and metrics, today’s release includes technical documentation for data users and analysts who plan to access and use the 2010 Redistricting NMF. 

There are approximately 25 trillion numbers associated with the combined 2010 Redistricting data and the 2010 DHC Noisy Measurement Files, consuming 33 terabytes of space in a compressed format. Given their large size, the files are housed and accessible via the Inter-university Consortium for Political and Social Research (ICPSR). For guidance on how to access and use these files, review materials on our FTP page.