[Federal Register Volume 68, Number 86 (Monday, May 5, 2003)]
[Notices]
[Pages 23693-23694]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-10952]


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DEPARTMENT OF COMMERCE

Bureau of the Census

[Docket Number 030328074-3074-01]


Revised Confidentiality Criteria for Bureau of the Census Public 
Use Data Products

AGENCY: Bureau of the Census, Department of Commerce.

ACTION: General notice.

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SUMMARY: The Bureau of the Census (Census Bureau) is issuing this 
Notice to update the criteria used to assess and review public use data 
products prior to their release. The criteria help ensure that 
confidential information is not inadvertently disclosed.

DATES: This notice is effective May 5, 2003.

FOR FURTHER INFORMATION CONTACT: Requests for additional information on 
this Notice should be directed to Laura Zayatz, Chair, Disclosure 
Review Board, Statistical Research Division, U.S. Census Bureau, Room 
3209, Federal Building 4, Washington, DC 20233, (301) 763-4955 or by 
fax at (301) 457-2299.

SUPPLEMENTARY INFORMATION:

Background

    Title 13, United States Code, Section 9, requires the Census Bureau 
to protect the confidentiality of individual respondents. Title 13 also 
requires the Census Bureau to release information from its data 
collections to the public. In order to comply with the latter 
requirement, while protecting respondents' confidentiality, the Census 
Bureau has developed standard procedures for protecting its data 
products from disclosure of identifying information. A Federal Register 
Notice (46 FR 22017) published on April 15, 1981, described those 
procedures.
    Since that Notice appeared, some methodological improvements have 
been introduced and additional formal review has been instituted. 
Specific changes to the earlier criteria are the following items under 
the ``Criteria for Releasing Public Use Microdata'' section of this 
Notice.
    [sbull] Paragraph (4). To ensure confidentiality protection, the 
Census Bureau now requires the completion of a Checklist on Disclosure 
Potential of Data.
    [sbull] Paragraph (4)(e). To better protect the confidentiality of 
data, the Census Bureau may require the use of data swapping. This 
technique is discussed further in that paragraph.
    [sbull] Paragraph (5). The name of the Microdata Review Panel was 
changed to the Disclosure Review Board.
    [sbull] ``Criteria for Releasing Public Use Tabular Data'' section. 
This entire section is new. In 1995, the routine review performed by 
the Disclosure Review Board was extended to include tabular data as 
well as microdata.
    Also, the scope of the Disclosure Review Board was enlarged to 
include setting disclosure limitation rules, monitoring the Census 
Bureau's adherence to its confidentiality policy requirements, and 
resolving any problems, questions, and issues not covered by the 
general criteria described in the earlier Federal Register Notice. This 
Notice updates the information previously published and includes 
criteria for releasing tabular data as well as microdata.

Confidentiality Criteria for Census Bureau Public Use Data Products

Data Subject to Disclosure Protection

    All data released to the public are subject to disclosure 
protection. These public use data products include both microdata and 
tabular data. Microdata

[[Page 23694]]

are records containing information about individuals or households, or 
about businesses, with all personal identifiers removed. Tabular data 
may be frequency counts (e.g., number of Hispanic males) or magnitude 
data presenting sums of a variable of interest (e.g., total value of 
sales) from individuals, households, firms, or establishments.
    Because some business firms and establishments are selected with 
certainty, the disclosure risk for economic microdata files can be 
quite high. For this reason, microdata files containing information on 
establishments are rarely produced. However, any economic microdata 
file produced for public release would be subject to disclosure 
constraints comparable to those provided for individual and household 
microdata files.
    Criteria for avoiding disclosure in data released by the Census 
Bureau for public use have been the subject of internal research, 
consultations with stakeholders, and input from experts in disclosure 
limitation techniques over the past few decades. Based on those 
findings and subsequent assessments of data needs and disclosure risk, 
the Census Bureau has established a release policy stating criteria for 
release. The Census Bureau will apply these criteria to all data 
products released to the public.

Criteria for Releasing Public Use Microdata

    Files of records containing data about households and individuals, 
or about businesses, can be made available for public use, provided the 
appropriate disclosure avoidance requirements have been met. For public 
use microdata about individuals and households, the following 
conditions must be met:
    (1) The records contain no names, addresses, or other unique 
identifiers.
    (2) The records include no geographic or related information that 
would identify an area of fewer than 100,000 population.
    (3) Once a file has been released with one set of geographic 
identification, the same records cannot be released with different 
identification if the two geographic schemes in combination identify 
any area with fewer than 100,000 population.
    (4) Specifications for each file (or groups of files) must be 
reviewed to assure that confidentiality is protected. To do so, the 
Census Bureau's Checklist on Disclosure Potential of Data must be 
completed by the data producers and reviewed by disclosure experts at 
the Census Bureau. (The Checklist is available on the Census Bureau Web 
site at http://www.census.gov/srd/sdc/index.html.) This review may 
result in:
    (a) The removal or reduction in detail of any variable considered 
likely to identify an especially small and visible population (e.g., 
persons with high income or rare demographic characteristics).
    (b) The use of a minimum area population criterion that is higher 
than 100,000 for that particular file(s) (e.g., for a file with 
neighborhood characteristics).
    (c) The introduction of ``noise'' (i.e., small amounts of random 
variation) into selected data items.
    (d) The subsampling of records so that public-use microdata do not 
include all respondents included in a large survey.
    (e) The use of data swapping (i.e., locating pairs of matching 
households in the database, based on a set of predetermined variables, 
and swapping those households across geographic areas to add 
uncertainty for households with unique characteristics).
    More information on these methods is provided on the Census 
Bureau's Internet site at http://factfinder.census.gov/home/en/confidentiality.html#microdata.
    (5) The Disclosure Review Board concurs that the data meet 
disclosure avoidance criteria for public release.
    Comparable criteria will be developed and applied in the event that 
microdata about businesses are being considered for public release.

Criteria for Releasing Public Use Tabular Data

    Although tabular data products had routinely undergone disclosure 
protection, it was not centralized. This Notice documents standardized 
procedures now in use that have been adopted to protect the 
confidentiality of information in frequency counts and magnitude data. 
Tabulations containing data about households, individuals, firms, and 
establishments can be made available for public use provided that:
    (1) Specifications for each file (or groups of files) are reviewed 
to assure that confidentiality is protected for any response provided 
by an individual, a household, a firm, or an establishment. To do so, 
the Census Bureau's Checklist on Disclosure Potential of Data is 
completed by the data producers and reviewed by disclosure experts at 
the Census Bureau. (The Checklist is available on the Census Bureau Web 
site at http://www.census.gov/srd/sdc/index.html.) This review may 
result in:
    (a) The removal or reduction in detail of any variable in a 
tabulation considered likely to identify an especially small and 
visible population or group of establishments.
    (b) The introduction of ``noise'' into selected data items.
    (c) The use of data swapping for selected households.
    (d) The use of rounding in selected tabulations.
    (e) The use of thresholds in selected tabulations.
    (f) The use of cell suppression (i.e., not displaying certain cell 
values that would identify unique cases in a table or disclose an 
individual response; often complementary cells also are blanked out to 
prevent disclosures by subtracting the balance from the total for a 
given row or column).
    (2) The Disclosure Review Board concurs that the data meet 
disclosure avoidance criteria for public release.

    Dated: April 29, 2003.
Charles Louis Kincannon,
Director, Bureau of the Census.
[FR Doc. 03-10952 Filed 5-2-03; 8:45 am]
BILLING CODE 3510-07-P