Scientists and Engineers With Disabilities
- Field of Science and Engineering
- Employment and Unemployment
- Sector of Employment
- The Disability Salary Gap
Persons with disabilities are also underrepresented in science and engineering. Comparisons of data on participation of persons with disabilities are difficult because of differences in definition.  It appears, however, that persons with disabilities are a smaller proportion of the science and engineering labor force than they are of the labor force in general. About 20 percent of the population have some form of disability; about 10 percent have a severe disability.  Persons with disabilities are 13 percent of all employed persons  and about 5 percent of the science and engineering labor force (see figure 5-1).
Doctoral scientists and engineers with moderate to severe disabilities make up about 5 percent of doctoral scientists and engineers in the United States. (See appendix table 5-42.) The proportion of scientists and engineers with disabilities increases with age. More than half became disabled at age 35 or later. Only 7 percent had been disabled since birth, and only one-fourth had been disabled before the age of 20. (See appendix table 5-43.)
The representation of persons with disabilities in the science and engineering population can be estimated by comparing the results of the NSF National Survey of College Graduates with similar results from the Bureau of the Census's Survey of Income and Program Participation.  Comparisons of the two survey results indicate that persons with significant sensory-motor disabilities are underrepresented among scientists and engineers. The Survey of Income and Program Participation found that in 1991-1992, 0.4 percent of the general population of 15-to-64-year-olds reported that they were unable to see words and letters. The comparable figure from the 1993 National Survey of College Graduates was 0.1 percent. In the total population, 0.2 percent were unable to hear normal conversations, compared with 0.02 percent of the scientists and engineers, and 1.9 percent of the general population reported being unable to lift a 10-pound bag of groceries, compared with 0.2 percent of the scientists and engineers. For those unable to climb stairs, the total population rate was 2.2 percent compared with 0.2 percent of the scientists and engineers.  
Field of Science and Engineering
Unlike women and minorities, persons with disabilities are not particularly concentrated in certain fields (see figure 5-24), although a somewhat higher fraction of those with doctorate degrees in the social sciences have disabilities (6.6 percent) than is true of those with doctorate degrees in science and engineering as a whole (5 percent).
See appendix table 5-42.
Employment and Unemployment
Recent Bachelor's Graduates
Recent bachelor's science and engineering graduates with disabilities are somewhat less likely than those without disabilities to enroll either full time or part time in graduate school. Twenty-six percent of 1992 bachelor's science and engineering graduates with disabilities were full-time or part-time graduate students in 1993, compared with 31 percent of comparable graduates without disabilities. (See appendix table 5-34.)
The unemployment rates of recent bachelor's science and engineering graduates with and without disabilities are similar. The unemployment rate for 1992 bachelor's science and engineering graduates with disabilities was 4.7 percent compared with 4.5 percent for those without disabilities. (See appendix table 5-34.)
Doctoral Scientists and Engineers
The labor force participation rates of doctoral scientists and engineers with and without disabilities are quite different. Almost one-quarter of doctoral scientists and engineers with disabilities are out of the labor force, compared with only 7 percent of those without disabilities. (See appendix table 5-36.) Among those in the labor force, persons with disabilities are more likely than those without disabilities to be unemployed or to be employed part time. The unemployment rate for doctoral scientists and engineers with disabilities was 2.4 percent compared with 1.6 percent for those without disabilities. The percentage of doctoral scientists and engineers in the labor force who were employed part time in 1993 was 11 percent for those with disabilities and 6 percent for those without disabilities. The lack of full-time employment may be particularly problematic for scientists and engineers with disabilities because those who are unemployed or employed part time are likely to have less access to health insurance.
Sector of Employment
Scientists and engineers with disabilities do not differ greatly from those without disabilities in terms of employment sector. Among bachelor's scientists and engineers, 68 percent of persons with disabilities are employed in business or industry, compared with 72 percent of those without disabilities. (See appendix table 5-14.) Among doctoral scientists and engineers, 27 percent of those with disabilities compared with 31 percent of those without disabilities are employed in business or industry. (See figure 5-25.) The fraction of doctoral scientists and engineers with disabilities who are self-employed is higher (9 percent) than the fraction of all doctoral scientists and engineers who are self-employed (6 percent).
See appendix table 5-16.
Doctoral scientists and engineers who are employed in universities and 4-year colleges and who have disabilities are more likely than those without disabilities to be full professors and to be tenured. (See figures 5-26 and 5-27.) This can be explained by differences in age. Because incidence of disability increases with age, scientists and engineers with disabilities tend to be older and to have more years of professional work experience than those without disabilities. Eighty-four percent of doctoral scientists and engineers with disabilities are pre-1985 graduates, compared to 67 percent of those without disabilities. (See appendix table 5-44.) Among pre-1985 graduates, the differences in rank and tenure status between persons with disabilities and persons without disabilities are narrower. For example, 59 percent of doctoral scientists and engineers with disabilities who received their doctorate prior to 1985 are full professors compared with 54 percent of comparable doctoral scientists and engineers without disabilities. (See appendix table 5-44.)
See appendix table 5-44.
See appendix table 5-44.
The type of work that bachelor's-level and master's-level scientists and engineers with disabilities do is not greatly different from the type of work done by those without disabilities. The primary work activity of 27 percent of bachelor's scientists and engineers with disabilities is computer applications, compared with 29 percent of those without disabilities. Design of equipment is the primary work activity of 15 percent of bachelor's scientists and engineers both with and without disabilities. Ten percent of bachelor's scientists and engineers with disabilities and 11 percent of those without disabilities are in management and administration. (See appendix table 5-39.)
Among doctoral scientists and engineers, those with disabilities are more likely than those without disabilities to be in management. (See appendix table 5-45.) Doctoral scientists and engineers with disabilities are older, on average than those without disabilities and thus are more likely to be in management. Among doctoral scientists and engineers age 45 and older and employed in business or industry, 32 percent of both those with disabilities and those without disabilities are in management. (See appendix table 5-45.)
The Disability Salary Gap
The Survey of Doctorate Recipients also permits an examination of the salary gap between persons with and without disabilities, comparable to that done for gender and racial/ethnic groups.  For the purpose of this analysis, individuals who were disabled by the time of receiving their doctorate degrees were differentiated from those who became disabled subsequent to receiving the degree.  This differentiation reflects the fact that the challenges faced by individuals who become disabled after earning their degrees may be different from the challenges faced by individuals who acquire a disability earlier in life.
The observed salary gaps between individuals with disabilities and those without were indeed quite different for those who had disabling conditions at the time of degree and for those who became disabled at a later point. Those in the first group had average salaries approximately $1,600 lower than those without disabilities, whereas those in the latter group had salaries that were $5,700 higher than those without disabilities. (See text table 5-7.) Individuals with late-acquired disabilities, however, are also considerably older than individuals without disabilities. The average length of time since receiving the doctorate was 22 years for those disabled after receiving a degree compared to 14 years for those without a disability and 15 years for those who had a disability by the time they received their doctorates. (See appendix table 5-32.) Adjusting for this difference in time since receipt of the degree explains almost all (85 percent) of the salary advantage of those with late-acquired disabilities compared to those without disabilities.
Other work-related employee characteristics also explain a substantial part (54 percent) of the salary gap between those with late-acquired disabilities and those without disabilities. Most of this difference is attributable to differences between the two groups in the number of years of full-time work experience. (See appendix table 5-32.)
After all of the variables included in the analysis are controlled for, unexplained salary gaps of approximately $1,100 are observed for both groups of persons with disabilities when compared with those without disabilities. Thus, among individuals with doctoral degrees in science and engineering, this rough estimate of the salary disadvantage of having a disability appears to be similar in size to the salary disadvantage of being female.
 The data on persons with disabilities in science and engineering are seriously limited for several reasons. First, operational definitions of "disability" vary and include a wide range of physical and mental conditions. Different sets of data use different definitions and thus are not totally comparable. (See appendix table 1-1.) Second, data about disabilities are frequently not included in comprehensive institutional records (e.g., in registrars' records in institutions of higher education). The third limitation on information on persons with disabilities gathered from surveys is that it often is obtained from selfreported responses. Typically, respondents are asked if they have a disability and to specify what kind of disability it is. Resulting data, therefore, reflect individual decisions to self-identify, not objective measures. Finally, data users should understand that sample sizes for the population of disabled persons may be small and care should be taken in interpreting the data.
 Estimates of the proportion of the population with disabilities vary due to use of different definitions of "disability." See Appendix A Technical Notes for a discussion of the limitations of estimates of the size of this group. The source of these estimates is the U.S. Department of Commerce, Bureau of the Census. 1993. Americans With Disabilities: 1991-92: Data from the Survey of Income and Program Participation (P70-33).
 U.S. Department of Commerce, Bureau of the Census. 1994. "Americans With Disabilities" (Statistical Brief SB/94-1).
 Because of several differences between the two surveys, comparisons can be made only for certain segments of the two populations.
 The question used in the National Survey of College Graduates combined stair climbing and walking, whereas the Survey of Income and Program participation asked about these two activities separately. The rate reported for the latter survey is for the activity with the higher reported disability rate.
 Small cell sizes restrict the analysis of types of disability to overall percentages of the science and engineering population.
 The methodological approach used in analyzing salary gaps is discussed in the section on gender salary gaps and in more detail in the chapter 5 Technical Notes.
 See the box on page xx for the definition of disability used here. Note that it would be possible to classify individuals by the type of their disability (seeing, hearing, walking, lifting) instead of by the age at which they became disabled, but small sample sizes precluded our using both classifications simultaneously. A regression analysis including both type of disability and age of disability indicated that age of disability was the more important determinant of salary.