PROCEDURES FOR RESEARCHER ACCESS TO CONFIDENTIAL MICRODATA

 AT THE BUREAU OF LABOR STATISTICS* 

Virginia A. de Wolf, Bureau of Labor Statistics

* For the latest information on researcher access to BLS microdata, see 

http://www.bls.gov/bls/blsresda.htm 

KEY WORDS: Confidentiality, Accessing

Sensitive Data, Privacy, Data Protection

The Bureau of Labor Statistics’ (BLS) mission is to

gather, produce, analyze, and disseminate information

on economic statistics. The bulk of the economic data

that BLS collects is from business establishments.

Most BLS economic data are collected under a pledge

of confidentiality. Since staff cannot conduct all

necessary (and possible) analyses on the data that BLS

collects, the agency sometimes relies on other

researchers (non-BLS staff) to do such work. The risk

of re-identifying confidential data collected from

establishments limits the access to these data (for

instance, public-use microdata files are rarely

released). BLS has developed a set of procedures to

enable access to confidential microdata on-site at its

national office in Washington, D.C., for legitimate

research purposes. This paper summarizes that

process. A brief description of BLS’s confidentiality

policy is also included.

1. Introduction

BLS disseminates data in a variety of ways. For

instance, macroeconomic data (such as tabular reports

and time series data via the Internet) are used by a

wide variety of researchers and organizations. While

BLS releases some public-use microdata files on

persons1

, it releases very few public-use microdata

files on business establishments due to the risk of reidentifying respondents. While wide dissemination of

public-use microdata sets on persons has yielded

substantial benefits to data users, agencies, and society

as a whole, similar returns have not been realized from

data collected from businesses and other

organizations; in fact, data collected from these

 

1

 BLS has three programs that distributed personbased public-use microdata files -- the National

Longitudinal Surveys of Youth, the Consumer

Expenditure Survey, and the Current Population

Survey.

sources have been called an “underutilized resource”

(Duncan et al., 1993, p. 200).

To enable the analyses of statistical data that cannot be

released as public-use microdata, Federal statistical

agencies have employed a variety of administrative

procedures to allow for researcher access. Jabine

(1993) called these ‘restricted access’ procedures since

they restrict the conditions under which a researcher

can obtain access to these data, and he described a

broad cross-section of such procedures in a 1993

paper. One restricted access procedure that BLS has

used is its ASA/NSF/BLS Fellows Program. Since its

inception in 1987, the Fellows Program has enabled

over 25 researchers to temporarily relocate to the BLS

national office in Washington, D.C., and to conduct

research and analyses on data that BLS collects.

These analyses have been very useful. However, the

Fellows Program has limitations and cannot fund all

of the worthwhile research proposals. In July 1995,

BLS formally adopted a standardized set of procedures

to process requests from individuals who want to

conduct research using confidential BLS microdata.

2. Confidentiality Policy

Before describing relevant activities, it is important to

briefly review BLS’ policy concerning confidential

microdata. The Bureau’s confidentiality policy is

contained in Commissioner’s Order 3-93, Confidential

Nature of BLS Records. Section 7(a) states that data

“...collected or maintained by, or under the auspices

of, BLS under a pledge of confidentiality shall be

treated in a manner that will assure that individually

identifiable data will be used only for statistical

purposes and will be accessible only to authorized

persons” (BLS, 1993, p. 2).

The designation of “authorized persons” is defined in

Section 8 of Commissioner’s Order 3-93. This

designation includes: individuals who need to use the

data as part of their duties as BLS employees or

contractors; State agency employees who are directly

involved in BLS/State cooperative programs;

employees of another Federal agency who are working

on a joint program with BLS; and Federal employees
from other agencies who are serving as BLS agents in

the conduct of BLS programs. Other individuals or

organizations may be granted access to confidential

BLS microdata only when authorized by the

Commissioner for a statistical purpose that furthers the

mission and functions of BLS.

3. Background

In 1993, the BLS Quality Council2

 chartered a

Microdata Access Review Team to “[d]evelop a set of

procedures to enhance access to confidential BLS

microdata for legitimate statistical and research uses

that further the mission and functions of BLS”

(de Wolf, 1994). One of the Team’s major

recommendations was to establish a unit in its national

office in Washington, D.C., that would support

projects by outside researchers using confidential BLS

microdata. While a long-term goal of the Quality

Council is to establish a centralized facility or facilities

to accommodate researchers who are granted access to

confidential BLS microdata, the costs involved in

setting up such a research center (or centers) were

determined to be prohibitive. Another alternative was

needed and the Team was asked to develop such an

alternative.

Based on the resulting work of the Team, BLS adopted

a set of standardized procedures to process requests

from researchers for access to confidential microdata.

All BLS program offices are required to follow these

procedures. Steps involved in the process can be

divided into three phases: the application phase, the

“on-site” phase, and the review phase.

4. Application Phase

There are three parts to the application phase:

Describing the proposed research: Each researcher

must submit a written request that adequately

describes the proposed research project. All use of

confidential BLS microdata must occur on-site at

BLS’s national office in Washington, D.C.

A request can be sent to a BLS program office or to

the Commissioner. Each request is entered into BLS’s

Controlled Correspondence System. Once a request is

entered, the researcher will receive an

 

2

 The Quality Council’s mission is to develop and

guide the BLS management effort.

acknowledgment letter from the Commissioner stating

that the request is being reviewed.

A written request should include a detailed plan

describing the research, as well as the general time

frame needed to conduct the research. Unless

researchers are already familiar with BLS data, they

should expect the application phase to take time in

order to clarify the proposal. In particular, it may be

necessary to interact several times with BLS staff to

understand precisely what variables are collected by

BLS and then incorporate this information into the

proposal.

Evaluating the proposed research: One major task of

BLS staff is to evaluate the research proposal. Once a

formal request is received, a program office has 30

days to evaluate the proposed research, prepare a

response to the request, and make a recommendation

to the Commissioner whether or not to accommodate

the request. The evaluation considers:

• the suitability of BLS data for the proposed

research;

• an assessment of whether there is a conflict

between the proposed research and the original

pledge of confidentiality made to the respondents

when these data were collected;

• whether the proposed research meets the criteria

set forth in Commissioner’s Order 3-93, i.e., that

the research project furthers the mission and

functions of BLS and that confidential data are

not being used for non-statistical purposes (which

is clearly prohibited by this Order); and

• the costs involved in accommodating the request -

- especially the amount of staff time needed to

assist the researchers as well as the staff and

computer resources required to prepare and

document the data files (some costs may be

recovered from the researcher).

Depending on the nature of the proposed research,

there may be several exchanges of letters and/or phone

calls between the researcher’s initial request and BLS’

final decision. As noted earlier, a researcher may not

clearly understand the limitations of the BLS data and

may modify the proposal based on information

provided by BLS staff. Another reason to modify a

request would be that a researcher could not afford to

pay BLS for recoverable costs involved in preparing a

data file to accommodate the initial proposal.
A recommendation to deny the proposed research must

clearly state the rationale for the denial. The

Commissioner reviews the BLS staff evaluation and

makes the final decision on whether to accommodate

or deny a request.

Completing institutional agreements: If a research

proposal is approved, two documents must be

completed before the researcher will be allowed onsite.

1. A Letter or Agreement (LOA) must be signed

between a “high-level official” at the researcher’s

organization and the BLS’ Commissioner. A

“high-level official” is defined as someone who

has the authority to “bind” the researcher’s

organization, such as a Vice President, Provost,

Center Director, or an official in a similar

position. (Note that the signature of the Chair of

a university department is not accepted.) The

LOA contains provisions concerning the

confidentiality and security of BLS data. The

researcher and his/her employer must agree to

abide by the terms of the LOA.

2. Each researcher who is granted access to

confidential BLS microdata must sign a “BLS

Non-disclosure Affidavit” acknowledging that

he/she has read, and understands, the BLS

confidentiality policy as stated in Commissioner’s

Order 3-93.

Once a proposal is accepted by BLS, there could be

other delays caused by the researcher’s organization.

Getting approval from BLS to come on-site to conduct

research is only half the battle, so to speak. Remember

that the official agreement is between the researcher’s

institution and BLS’ Commissioner. (For example,

one organization would not agree to sign the LOA for

one of its post-doctoral fellows and put a halt to the

process. In another instance, a university had its legal

office review the LOA and this took additional time.)

5. Working On-site at BLS’ National Office

Maintaining the confidentiality of the data that it

collects is of paramount importance to BLS. Program

offices are required to take stringent security

precautions. Researchers must be diligent and follow

these required procedures. Several of the possible

precautions are listed in the LOA and include:

• accessing confidential data only at the BLS

national office in Washington, D.C.;

• not removing tapes, CD-ROMs, diskettes, etc.,

containing confidential information from BLS;

• not linking the confidential data with individually

identifiable records from any BLS or non-BLS

data set (unless such a linkage has been

approved);

• not using the confidential information for the

purpose of identifying respondents in any way;

• following strict computer security procedures (for

example, researchers can have access to only

those data elements needed to complete their

projects, cannot have access to the Internet while

at BLS, and may be required to follow special

procedures if their research involves the use of

large data sets); and

• being required to sit in a “secure area” while at

BLS.

These precautions may seem strict to researchers who

are used to having flexibility in how they do their

analytic research, when they do it, and where it is

done. For instance, many professors work at home

and are quite used to carrying diskettes of data back

and forth from the office to home. This is not allowed

when they do research at BLS. Individuals who want

to conduct research at BLS need to be aware of these

limitations.

6. Review of Final Products

Researchers must present their final written reports to

BLS for a confidentiality review. This consists of

reviewing the analyses for breaches of confidentiality

and it does not entail review of conclusions or

findings.

It is difficult to generalize exactly the steps taken in a

confidentiality review since each BLS program has its

own set of rules and procedures regarding statistical

methods used to limit disclosure. As a first step such a

review would include the rules already used to limit

disclosure. Additionally, the LOA requires the

researcher to:

• avoid direct or indirect disclosure of respondents

or the confidential data they have reported (it

notes that particular attention should be paid to

tables containing cells with a small number of

respondents);
• not disseminate or share any aggregate or

summary data with non-authorized persons prior

to the confidentiality review;

• provide BLS with copies of reports, papers, etc.,

based on the confidential information; and

• have all reports that use confidential information

reviewed by BLS prior to publication or release to

non-authorized persons.

7. Summary

One observation concerning the research proposals

that have been processed during the past few months is

that it takes much more time than anyone might

expect. It takes time to refine the proposal. It takes

time to process a LOA, especially when it involves

legal/contracting officers at the researcher’s

organization. BLS staff have responsibility to process

data to meet publication deadlines and this

responsibility takes precedence over processing

researcher requests. Often the documentation

necessary to analyze BLS databases is not in a

“researcher-friendly” format and this causes delays.

BLS considers this to be an evolving process. As the

number of approved researcher requests increases and

more databases are accessed, one of the benefits would

be the continued development of “researcher-friendly”

documentation and databases. Of course, many of the

analyses conducted by researchers are valuable in-andof-themselves.

This could be called a “centralized, decentralized”

approach. It is centralized because all program offices

must follow the same procedures when handling each

request. It is decentralized because the program office

responsible for the microdata reviews the application

and makes the assessment about the suitability of the

proposed research. Obviously, a centralized unit

would make some aspects of this process easier; for

example, security precautions would no longer be a

concern of the program office.

References

Bureau of Labor Statistics. (August 18, 1993).

Confidential Nature of BLS Records.

(Commissioner’s Order 3-93). Washington, DC: U.S.

Department of Labor, Bureau of Labor Statistics.

de Wolf, V.A. (1994). Enhancing Researcher Access

to Economic Microdata at the Bureau of Labor

Statistics. Proceedings of the American Statistical

Association, Government Statistics Sections.

Duncan, G.T. Jabine, T.B., & de Wolf, V.A. (1993).

Private Lives and Public Policies: Confidentiality

and Accessibility of Government Statistics.

Washington, DC: National Academy Press.

Jabine, T.B. (1993). Procedures for Restricted Data

Access. Journal of Official Statistics, 9(2), 537-589.

Author’s Notes: (1) The views expressed in this

paper are those of the author and do not necessary

represent those of the Bureau of Labor Statistics. (2)

Copies of BLS documents referenced in this paper

(Letter of Agreement, Non-disclosure Affidavit, and

Commissioner’s Order 3-93) can be obtained from:

BLS, Division of Management Systems, Room 3255, 2

Massachusetts Ave., N.E., Washington, D.C. 20212-

0001. Phone: 202-606-7628.