On April 28, the U.S. Census Bureau released a new set of “demonstration data” to help the data user community evaluate the latest update to the new Disclosure Avoidance System to enhance protection of 2020 Census redistricting. The demonstration data use previously released 2010 Census data to illustrate the impact of the latest iteration of the new system.
The release, in the form of “Privacy-Protected Microdata Files,” is the first that reflects an increase in the “privacy-loss budget” (PLB). The “budget” has nothing to do with any sort of financial value. It refers to a chosen limit on how much privacy is traded for increased accuracy. That increased PLB is reflected in the accuracy of population counts and demographic characteristics at various levels of geography.
The updated release uses a privacy-loss budget of 10.3 for persons and 1.9 for housing units (approximating the anticipated final PLB level). All previous “beta” releases used a privacy-loss budget of 4.0 for persons and 0.5 for housing units for development comparison purposes.
Data users are encouraged to analyze the demonstration data and share their feedback with the Census Bureau. Data users should send their responses directly to the Census Bureau at 2020DAS@census.gov. (Include “April PPMF” in the subject line.) The Bureau is accepting feedback until May 28, 2021.
You may find tabulations recently posted on the IPUMS site to be helpful. The tabulations, which are from the recently released 2021-04-28 Privacy Protected Microdata File (PPMF), are available here. The actual microdata file can be accessed here.
The 2021-04-28 PPMF consists of two microdata files. Both files were created using the same codebase and the same fractional allocations to queries and geographic levels. The only difference between the files is the global privacy loss budget. One file uses a global PLB of 12.2, with 10.3 allocated to person-level data and 1.9 allocated to housing unit-level data. The second file uses a global PLB of 4.5, with 4.0 allocated to person-level data and 0.5 allocated to housing unit-level data.
The PAA leadership strongly encourages interested members to take advantage of this important, unique opportunity to share their feedback with the Census Bureau and to influence the outcome of the very consequential steps that the agency will be taking to develop and implement its new Disclosure Avoidance System.
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