DOI: 10.3886/icpsr38937
title: 2020 Census Demographic and Housing Characteristics (DHC) Noisy Measurement File (NMF)
title: Archival Version

description: The 2020 Census Demographic and Housing Characteristics Noisy Measurement File is an intermediate output of the 2020 Census Disclosure Avoidance System (DAS) TopDown Algorithm (TDA) (as described in Abowd, J. et al [2022], and implemented in DAS_2020_DHC_Production_Code/das_decennial/programs/engine/primitives.py at main uscensusbureau/DAS_2020_DHC_Production_Code (github.com) The 2020 Census Demographic and Housing Characteristics Noisy Measurement File includes zero-Concentrated Differentially Private (zCDP) (Bun, M. and Steinke, T [2016]) noisy measurements, implemented via the discrete Gaussian mechanism (Cannone C., et al., [2023] ), which added positive or negative integer-valued noise to each of the resulting counts. These are estimated counts of individuals and housing units included in the 2020 Census Edited File (CEF), which includes confidential data collected in the 2020 Census of Population and Housing.
The noisy measurements included in this file were subsequently post-processed by the TopDown Algorithm (TDA) to produce the Census Demographic and Housing Characteristics Summary File. In addition to the noisy measurements, constraints based on invariant calculations --- counts computed without noise --- are also included (with the exception of the state-level total populations, which can be sourced separately from data.census.gov).
The Noisy Measurement File was produced using the official "production settings," the final set of algorithmic parameters and privacy-loss budget allocations that were used to produce the 2020 Census Redistricting Data (P.L. 94-171) Summary File and the 2020 Census Demographic and Housing Characteristics File.
The noisy measurements are produced in an early stage of the TDA. Afterward, these noisy measurements are post-processed to ensure internal and hierarchical consistency within the resulting tables. The Census Bureau has released these noisy measurements to enable data users to evaluate the impact of disclosure avoidance variability on 2020 Census data. The 2020 Census Demographic and Housing Characteristics (DHC) Noisy Measurement File has been cleared for public dissemination by the Census Bureau Disclosure Review Board (CBDRB-FY22-DSEP-004).
These data are available for download (i.e. not restricted access). Due
to their size, they must be downloaded through the link on this metadata
page
and not through the standard ICPSR download. The link will take you to the
Globus site where these
data are housed. A README file is located in the Globus repository. Please
refer to
that for pertinent information.
The Globus holding site requires users to create an account to access
these data. Accounts can be created through existing institutional access
and by
personal access.
Please see the Globus "How to get
Started" page for more information.
description: Datasets: 
DS1: 2020 Census Demographic and Housing Characteristics (DHC) Noisy Measurement File (NMF)
description: Visit the U.S. Census
Bureau's Disclosure Avoidance Modernization page to learn more
about the use of differential privacy in the 2020 Census.Copies of the original data collection instruments can be found at: Decennial Census Questionnaires and Instructions.The readme is located here: 2020_DHC_NMF_README.