38 Monthly Labor Review June 2001

Research Summary Research Summary

The lack of a disability

measure in today's

Current Population

Survey

Thomas W. Hale

Thomas W. Hale is an economist in the Office

of Employment and Unemployment Statistics,

Bureau of Labor Statistics.

e-mail: hale_t@bls.gov

Acommon practice is to use data based on the Current Population

Survey (CPS) to demonstrate that the employment-population ratios for people

with disabilities deteriorated over the

1990s. This finding is counter-intuitive

given the employment growth in the

general population over this period, so

various researchers have attributed the

decline to the Americans with Disabilities Act (ADA) requirement for reasonable accommodations for persons with

disabilities and the failure of the U.S.

Equal Employment Opportunity Commission to adequately enforce the ADA.

There are two flaws with the analyses. The first defect, and the focus of

this article, is that there are no questions

in the Current Population Survey that

identify persons with disabilities.1 The

second defect is attributing the decline

to a specific statute or Federal agency

when there is no data from the CPS that

would provide empirical evidence linking the decline to a specific agency or

statute. Therefore, conclusions by researchers about the employment rate

trend for persons with disabilities and

the underlying causes are not valid.

The questions

There are two sources in the CPS that

have been used to measure employment

trends among persons with disabilities.

The first is from the basic CPS. (The basic CPS contains the questions that are

asked every month to determine the employment status of household members.) The second is from the CPS income

supplement that is appended once a

year to the March basic CPS. (The income supplement provides information

about work experience, earnings, and income in the previous calendar year.)

Typically, researchers use data derived

from both sources of the CPS to estimate

the employment-population ratio for the

population with disabilities.

The basic CPS questions are organized to first determine if the respondent

is employed or unemployed (that is, actively looking and available for work). If

the respondent does not meet the criteria for either category, he or she then is

classified as “not in the labor force.”

When individual respondents or their

proxies are asked if they did any work

for pay or profit (a “yes” or “no” question), some instead respond that they

have a disability, which is recorded. (No

list of possible alternative responses is

read to the respondent.) Following is the

question on disability from the basic

CPS:

 Q20. LAST WEEK, did you do ANY

work for (either) pay (or profit)?

o Yes

o No

o Retired

o Disabled

o Unable to work

o Don’t know

o Refused

Respondents who answer “yes” to

this question are asked to give details

about their employment, such as how

many hours they worked, and in which

industry and occupation they were employed. If the respondents answer “no,”

or give an alternative answer such as

“disabled,” the interviewer probes further to make sure they have not forgotten about some kind of work they did, or

whether they had a job from which they

were absent because of vacation, illness,

and so forth. If it is determined that the

respondents did no work for pay or

profit, the interviewer then moves to

another battery of questions to try to

determine if respondents meet the criteria for being classified as unemployed.

Failing that, respondents are classified

by default as “not in the labor force.”

If the respondent meets the criteria

for either employed or unemployed, the

response of “disabled” is erased from

the file because it is inconsistent with

the labor force categories of employed

and unemployed. Because of this, researchers have no information on the

disability status of employed and unemployed persons from the basic CPS.

Moreover, the alternative answers to

the question are not mutually exclusive.

The fact that a person said he or she was

retired did not mean they did not have a

disability. Hence, not only is the basic CPS

unable to identify employed and unemployed persons with disabilities, it cannot

fully measure the extent of disability

among the “not in labor force” group. Perhaps most important is that most retired

people and people with disabilities simply

say “no” to the work question because

the interviewer had not asked about their

retirement or disability status.

Most researchers who use the CPS to

develop data on the employment status

of persons with disabilities realize that

the basic CPS does not provide them with

the information they need. Thus, they

turn to the second source—income

supplement data from the March CPS. As

the name suggests, a primary purpose

of the income supplement is to determine sources and amounts of income.

The income supplement is the source of

Federal data on poverty and the working poor.

From the income supplement, researchers typically use the questions on

work limitation and income to inquire

about the receipt of Supplemental Security Income (SSI) or Social Security Disability Income (SSDI) payments to define

the population with disabilities.

Following is the work limitation question from the March 1999 Current Population Survey income supplement:
Monthly Labor Review June 2001 39

Q59a. (Do you/Does anyone in this

household) have a health problem or

disability which prevents (you/them)

from working or which limits the kind or

amount of work (you/they) can do?

o Yes

o No

If individuals respond “yes” to the

work limitation question, they are assumed to have a disability. The questioning then moves to identify sources

of income related to the disability, such

as workers’ compensation, disability insurance, State or local government disability, and State temporary sickness.

Persons collecting such benefits might

be assumed to have a disability. (As

noted earlier, they would have been

asked this question only if they responded positively to the work limitation question.) Researchers then cross

tabulate the responses from the question on work limitation with the responses from questions on labor force

status in the basic (March) CPS to determine the employment and unemployment rates of those who responded

positively to the work limitation and disability income questions.

At first glance, these questions seem

to provide a reasonable means of identifying the population with disabilities.

However, a closer examination leads to

the conclusion that the questions lack

validity as identifiers of persons with disabilities. In the case of disability, a valid

question would be written in a way such

that the people who were envisioned to

have a disability would identify themselves when asked the question. Understanding the validity characteristics

of survey questions is key to understanding what the data mean. For example, suppose one defines a person

with a disability as someone with an

impairment or condition that limits him

or her in a major life activity. This is the

first prong of the ADA definition of disability. Question 59a in the March CPS

supplement certainly identifies some

such people, but also may identify

people with the flu, colds, broken legs,

and other temporary illnesses or conditions. In this case, the survey question

is not valid. Because a “yes” response

to the work limitation question does not

differentiate between a person with an

impairment that limits the ability to

work, and a person with a temporary

health problem, this question could not

be used to positively identify the population with disabilities (as defined in the

ADA in our example).

The procedure for designing valid

disability questions starts with the definition of disability. Then questions

should be constructed in a way that will

evoke positive responses from those

who fit that definition. Tests, such as

cognitive tests and field tests, should

be undertaken to determine if a question does the job for which it was designed.

The current CPS questions on work

limitation and disability income did not

begin with any definition of disability.

In fact, the purpose of the work limitation question is to serve as a screen for

the income questions. It was specifically designed to direct respondents to

questions on sources of income. Neither the work limitation nor the income

questions were designed to identify the

population with disabilities, nor were

they tested to determine if they do so.

In the March CPS income supplement, disability is defined as a health

condition or other disability that makes

a person unable to work or limits the

ability to work. This is an extremely narrow (and circular) definition of disability. In the ADA definition (which BLS has

adopted in its efforts to design proper

disability questions for the CPS), there

is no reason to believe a person with a

disability is limited or unable to work.

Indeed, the purpose of the ADA is to

enhance the employment prospects of

people with disabilities and, therefore,

the default assumption of the ADA is that

such individuals can work. The work limitation and income questions in the

March income supplement might identify a subset of the disability population (an untested empirical question),

but they are not likely to capture the

larger population with disabilities.

Elements of uncertainty

In addition to issues of validity, the CPS

questions (both in the basic and the

March income supplement) have several elements that add uncertainty to

their utility as identifiers of the population with disabilities. There is a temporal element—how long must a health

problem or impairment last before it

qualifies as a disabling condition?

Does the health dimension to this question mean we are identifying as disabled

those with temporary conditions such

as the flu or a broken leg? A health condition can be coincident with a disability and it could cause the disability, but

blindness, deafness, spinal cord injury,

or missing limbs generally are not considered to be health conditions. However, depression, heart conditions, and

diabetes might be considered as prerequisite health conditions for disability status. Other health conditions

clearly would not present a qualifying

precondition for disability status, because the ongoing pathology is not long

lasting (for example, a cold), and if it is, it

might not present a substantial limitation (for example, a case of mild hypertension). Of course, if respondents report that this condition substantially

limits their ability to work, the condition would qualify as a disability.

Another element that adds uncertainty to the CPS questions utility as

identifiers of the population with disabilities is the fact that work is only

one of many major life activities in

which one might have difficulties.

There are long lists of activities that

might apply in the ADA definition, including parenting, learning, playing,

getting around inside the home, shopping, counting money, lifting, making

and maintaining relationships, read-
40 Monthly Labor Review June 2001

Research Summary

ing, and conversing.

Indeed, work goes beyond an activity of daily living in terms of difficulty;

it may be one of the most complex

things we do because it requires the coordination of multiple activities, such

as learning, eating, dressing, bathing,

and the ability to use public or private

transportation, among others. Even if a

person can do all of these things but

with great difficulty and they hold a job,

that person might not respond that he

or she is limited in the type or amount

of work performed and so would not be

identified by work limitation questions

or by the source of income questions.

Thus, it is plausible that many people

who work and also have a disability (under the ADA definition) would not consider themselves limited in the type or

amount of work they can do. The CPS

question asks them to identify some

failing about themselves. Why should

they—after all, they are working.

Another element of uncertainty can

be seen in the data from the U.S. Bureau of the Census Survey of Income

and Program Participation (SIPP). These

data show that certain people with specific types of disabilities do not selfidentify unless asked about the disabilities directly—those with blindness, deafness, and learning disabilities, for example. Some of the individuals surveyed in SIPP responded that

they had these conditions, but did not

get identified by questions on particular activity limitations.2

 These individuals also are not likely to be identified by

the work limitation question in the SIPP.

There are likely to be wide crosscultural variations in how “health condition” and “disability” are defined.

There also are likely to be major gender

differences and gender crossed by cultural differences in the definition. Given

the mind-body split assumption of most

western populations, a mental condition

is not likely to be considered a “health

condition” or “disability” for many.

“Work” is another definitional issue

that adds to the uncertainty. Individuals working in a job that they believe to

be significantly below their capabilities

(such as a data entry clerk with a background in programming rockets for

NASA), might say they are limited in the

type of work they can do. How would

the survey researcher know if the limitation was because of a disability, or

because it was the only job that individual could find? The question does

not tease out this difference. If someone acquired a disability and was not

able or allowed to work in the job he or

she was trained to do, and instead had

to accept a menial “substitute” job, that

person might not report that he or she

was working, out of shame or a sense

of failure. Also, the work limitation

question in the March income supplement does not differentiate between

work as a means of obtaining a living,

and work as a meaningful use of time.

Hence, when the March income supplement question asks about work limitation, the respondent who does volunteer work could easily assume that volunteer work is included. Volunteer work

in the basic CPS, of course, is not included in the employment concept—

the question asks “...did you do any

work for pay or profit?”

Remedying the inadequacy

Are the CPS data “valid” for measuring

the employment-population trends of

persons with disabilities? This is an

empirical question, and given that the

questions in the CPS are not designed

to measure a specific definition of disability, the burden of proof is on those

who use the data to infer the labor force

status of people with disabilities. To

proceed as though the data are valid

measures of disabilities turns a data issue into a policy issue.

The Bureau of Labor Statistics recognizes that an adequate measure of the employment status of persons with disabilities may not exist, either from the CPS in its

current form, or from other surveys.

Working under the auspices of Executive

Order 13078 (which calls for the development of an accurate and reliable employment rate for adults with disabilities),

and in conjunction with the Presidential Task Force on the Employment of

Adults with Disabilities and more than

15 other Federal agencies, a set of questions has been identified and are being

tested for possible inclusion in the CPS.

The Executive Order requires that measures of individuals with disabilities be

accurate and reliable. The first steps necessary to produce meaningful statistics

are being undertaken.

1 The Current Population Survey (last revised in 1994) is the official source of employment and unemployment data for the

United States. It is a monthly survey of about

50,000 households, or 100,000 people. This

is the vehicle through which employment and

unemployment data on the protected classes

are gathered.

Based on responses to a series of questions on work and job-search activities, each

person 16 years and older in a sample household is classified as employed, unemployed,

or not in the labor force. A detailed explanation of labor force definitions appears on

page 51 of this issue.

2 Survey of Income and Program Participation, Bureau of the Census, 1994–95.

Notes