# Presentation: 711472

## Overview of New Legislation Protecting Confidentiality of Statistical Information and Statistical Disclosure Limitation Methodologies

*Nancy Kirkendall *
*Director of Statistics and Methods Group *
*Energy Information Administration (EIA)*

- BTS Confidentiality Seminar Series, Feb. 2003

## Main Topics for this Seminar

- New law
- How it affects statistical agencies
- How my agency, the Energy Information Administration, is reacting
- Statistical disclosure limitation methodologies to protect confidential information

## Confidential Information Protection and Statistical Efficiency Act of 2002 (CIPSEA)

- Title V of E-Government Act of 2002, Public Law 107-347
- Signed into law December 17, 2002
- Entire E-Gov Act is 72 pages; CIPSEA is on last 9 pages
- Available at
-             http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=107_cong_public_laws&docid=f:publ347.107.pdf

## CIPSEA

- Subtitle A, Confidential Information Protection
- Offers a consistently high level of  protection to all statistical data collected under a pledge of confidentiality
- Subtitle B, Statistical Efficiency
- Directed toward sharing of business data by Census, BEA, and BLS; this subtitle has no direct effect on other agencies

## CIPSEA Subtitle A, Confidential Information Protection

- An agency may collect information under a pledge of confidentiality for exclusively statistical purposes
- Such information may not be disclosed in identifiable form for any nonstatistical purpose without the informed consent of a respondent
- Such information is also exempt from release under the Freedom of Information Act (FOIA)

## Statistical and Nonstatistical Purposes

- Statistical purposes include using  information to describe or make estimates about whole or subgroups of the economy, society, or the environment
- Nonstatistical purposes include using information for administrative, regulatory, law enforcement, judicial, or other purposes that may affect the rights, privileges, or benefits of a respondent

## CIPSEA Benefits for Federal Statistical Agencies

- Most agencies did not have specific laws ensuring confidentiality of information
- Agencies can now better protect data collected for exclusively statistical purposes
- Higher level of confidentiality may encourage respondents to participate in surveys
- Agencies can avoid disputes about withholding from release under FOIA

## CIPSEA Effects on Agencies

- An agency may designate information as being for exclusively statistical purposes
- Information collected under CIPSEA
- Cannot be shared for nonstatistical purposes
- Can be shared for statistical purposes by entering into special written agreements, agent bound to provide same level of protection
- In EIA’s case, CIPSEA overrides existing laws that required EIA to share for official purposes which could be nonstatistical
- A statistical agency must clearly explain to respondents before any information is collected if it is to be used for nonstatistical purposes

## EIA View of Survey Confidentiality Options

- CIPSEA - Confidential and for exclusively statistical purposes
- Confidential, but not for exclusively statistical purposes; agency may withhold from public release using other laws such as FOIA and the Privacy Act
- Not confidential and may be publicly released in identifiable form

## EIA Actions

- Consult with OMB and DOE/OGC
- Create a team to examine EIA surveys and determine confidentiality appropriate to each
- In particular, what data/information should be included into the new CIPSEA confidentiality category?
- Likely possibilities end-user  and other sample surveys
- Inclusion in this new category precludes any future sharing of information for nonstatistical purposes (e.g., DOE/Policy, FERC, EPA, DOJ)

## EIA Adoption of CIPSEA Confidentiality for Surveys

- Develop wording for all pledges of confidentiality
- Discuss with OMB, obtain clearance
- Notify respondents (by mail for on-going surveys, in instructions for upcoming surveys)

**Notes:**
-Class E felony with prison up to 5 years and/or $250,000 fine for willfully disclosing such information to a person or agency not entitled to receive it

## Other EIA Actions

- Training for EIA staff on CIPSEA
- Surveys covered
- Additional procedures for protecting data
- CIPSEA fines and penalties (Class E felony with prison up to 5 years and/or $250,000 fine for willfully disclosing such information to a person or agency not entitled to receive it)

## Confidential Survey Information May Be In Different Formats

- Completed survey forms
- Electronic files and printouts
- Information products such as printed publications and web site information
- Public-use microdata files (information about individual survey respondents)

## Disclosure Limitation Methodologies

- Statistical agency must have controls to ensure protection of confidential information
- Actions to protect the information
- Internal procedures
- Aggregate information used in agency products such as tables, charts, graphs, and text
- Microdata; i.e., information about individual survey respondents

## Disclosure Limitation in Tables

- Ensure that aggregate data do not inadvertently disclose individually-identifiable confidential survey information
- For example, a data cell in a table may represent responses from only one or two respondents or the cell may be dominated by a small number of large respondents

## Disclosure Limitation Methods for Tables

- Cell suppression is most common
- Do not release a cell if it may be used to estimate confidential information (called primary suppression)
- May also require not releasing one or more other cells to ensure the sensitive cell cannot be determined (called complementary suppression)

## Coal Stocks at Other Industrial Plants by Census Division and State (Thousand Short Tons) 

| Census Division  | 9/30/2002 | 6/30/2002 | 9/30/2001 | % difference 9/3002  vs 9/30/01 |
| --- | --- | --- | --- | --- |
| Mid Atlantic Total | W | W | W | W |
|    New Jersey | W | W | W | W |
|    New York  | 296  | 235 | 199 | 48.6 |
|    Pennsylvania | 202  | 215 | 187 | 7.9 |
| W = Withheld to avoid disclosure of individual company data.
Note:  Total may not equal sum of components because of independent rounding.
Source:  EIA’s Quarterly Coal Report, http://www.eia.doe.gov/cneaf/coal/quarterly/html/t35p01p1.html |  |  |  |  |

- Primary

- Complementary

## Alternative to Suppression

- New method being developed will use synthetic data to protect confidentiality
- Add or subtract a small amount to cell value so respondents cannot use it to estimate value of other respondents too accurately.
- May be implemented using rounding

## Primary Suppression Rules for Tables

- Rules for determining if a cell is sensitive and requires primary suppression
- n, k rule focuses on number of respondents represented in a cell’s value and the percentage contributed by the larger respondents
- pq rule
- p-percent rule
- Combination

## Primary Suppression Rules (Cont’d)

- Recommend using one of the above rules, or a combination
- They are simple and have important mathematical properties (union of nonsensitive cells is not sensitive)
- Rules are described in detail in Statistical Policy Working Paper 22, Report on Statistical Disclosure Limitation Methodology
-      http://www.fcsm.gov/working-papers/spwp22.html

## Hint

- If a table has too many suppressions, data not useful
- Redesign, combining categories to make a table with fewer suppressions

## Disclosure Limitation Methods for Public Use Microdata Files

- Public use microdata files consist of records that contain individual information on persons, businesses, or other entities
- Used for analytical and research purposes
- Agency must ensure that confidentiality is maintained

## Disclosure Limitation Methods for Microdata Files Include

- Rounding
- Top and bottom coding
- Recoding
- Collapsing categories
- Data swapping
- Adding noise
- Suppressing individual records or certain variables from all records

## Responsibilities for Confidentiality

- Agency and its contractors are responsible for ensuring confidentiality of survey information
- Broken confidentiality promise has potential for severe negative consequences
- Including 5 years in prison/$250K in fines for willful disclosure

## Additional References and Background Materials

- Federal Committee on Statistical Methodology (FCSM), Statistical Policy Working      Paper 22, Report on Statistical Disclosure Limitation Methodology
-      http://www.fcsm.gov/working-papers/spwp22.html
- ASA Committee on Privacy & Confidentiality is creating a Privacy, Confidentiality, and Data Security Training Website (available Spring 2003)
- http://www.amstat.org/Comm/index.cfm?fuseaction=commdetails&txtComm=CCNMS10

## Background (continued)

- FCSM’s Confidentiality and Data Access Committee (CDAC) http://www.fcsm.gov/committees/cdac/cdac.html
- CDAC’s web site includes materials on:
- Checklist on Disclosure Potential of Proposed Data Releases
- Confidentiality and Data Access Issues Among Federal Agencies
- Restricted Access Procedures
- Panel on Disclosure Review Boards of Federal Agencies
- Identifiably in Microdata Files

## Contact Information

- Nancy KirkendallStatistics and Methods Group, EI-70Energy Information AdministrationU.S. Department of EnergyPhone:  202-287-1706Fax:      202-287-1705E-mail:  Nancy.Kirkendall@eia.doe.gov