Open AccessDifferential privacy in the 2020 US census: what will it do? Quantifying the accuracy/privacy tradeoff
Author(s) -
Samantha Petti,
Abraham D. Flaxman
Publication year - 2019
Publication title -
gates open research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.069
H-Index - 9
ISSN - 2572-4754
DOI - 10.12688/gatesopenres.13089.1
Subject(s) - census , computer science , differential privacy , sample (material) , information privacy , data collection , simple random sample , population , internet privacy , computer security , data mining , statistics , mathematics , demography , chemistry , chromatography , sociology
Background: The 2020 US Census will use a novel approach to disclosure avoidance to protect respondents’ data, called TopDown. This TopDown algorithm was applied to the 2018 end-to-end (E2E) test of the decennial census. The computer code used for this test as well as accompanying exposition has recently been released publicly by the Census Bureau. Methods: We used the available code and data to better understand the error introduced by the E2E disclosure avoidance system when Census Bureau applied it to 1940 census data and we developed an empirical measure of privacy loss to compare the error and privacy of the new approach to that of a simple-random-sampling approach to protecting privacy. Results: We found that the empirical privacy loss of TopDown is substantially smaller than the theoretical guarantee for all privacy loss budgets we examined. When run on the 1940 census data, TopDown with a privacy budget of 1.0 was similar in error and privacy loss to that of a simple random sample of 50% of the US population. When run with a privacy budget of 4.0, it was similar in error and privacy loss of a 90% sample. Conclusions: This work fits into the beginning of a discussion on how to best balance privacy and accuracy in decennial census data collection, and there is a need for continued discussion.