Science and Engineering Indicators 2014

Chapter 3. Science and Engineering Labor Force

Definition of the S&E Workforce

Because there is no standard definition of S&E workers, this section uses multiple categorizations to measure the U.S. S&E workforce. In general, this section defines the S&E workforce to include people who either work in S&E occupations or hold S&E degrees.^[1] The application of S&E knowledge and skills is not limited to jobs with formal S&E titles; the number of college graduates reporting that their jobs require at least a bachelor’s degree level of knowledge in one or more S&E fields exceeds the number of workers employed in S&E occupations in the economy. Therefore, this section also presents data on the use of S&E technical expertise on the job to provide an estimate of the U.S. S&E workforce. The estimated number of scientists and engineers varies based on the criteria applied to define the S&E workforce.

U.S. federal occupation data classify workers by the activities or tasks they primarily perform in their jobs. The NSF and Census Bureau occupational data in this chapter come from federal statistical surveys in which individuals or household members provide information about job titles and work activities. This information is used to classify jobs into standard occupational categories based on the Standard Occupational Classification (SOC) system.^[2] In contrast, the BLS-administered OES survey relies on employers to classify their workers using SOC definitions. Differences between employer- and individual-provided information can affect the content of occupational data.

NSF has developed a widely used set of SOC categories that it calls S&E occupations. Very broadly, these occupations include life scientists, computer and mathematical scientists, physical scientists, social scientists, and engineers. NSF also includes postsecondary teachers of these fields in S&E occupations. A second category of occupations, S&E-related occupations, includes health-related occupations, S&E managers, S&E technicians and technologists, architects, actuaries, S&E precollege teachers, and postsecondary teachers in S&E-related fields. The S&E occupations are generally assumed to require at least a bachelor’s degree level of education in an S&E field. The vast majority of S&E-related occupations also require S&E knowledge or training, but an S&E bachelor’s degree may not be a required credential for employment in some of these occupations. Examples include health technicians and computer network managers. Other occupations, although classified as non-S&E occupations, may include individuals who use S&E technical expertise in their work. Examples include technical writers who edit scientific publications and salespeople who sell specialized research equipment to chemists and biologists. The NSF occupational classification of S&E, S&E-related, and non-S&E occupations appears in table 3-2 along with the NSF educational classification of S&E, S&E-related, and non-S&E degree fields.

Other general terms, including science, technology, engineering, and mathematics (STEM), science and technology (S&T), and science, engineering, and technology (SET), are often used to designate the part of the labor force that works with S&E. These terms are broadly equivalent and have no standard definition.

The number of individuals who have S&E training or who reported applying S&E technical expertise in their jobs exceeds the number of individuals employed in S&E occupations. A relatively narrow definition of the S&E workforce consists of workers in occupations that NSF designates as S&E occupations. A much broader definition of an S&E worker, defined by SESTAT, includes any individual with at least a bachelor’s (or higher) degree in an S&E or S&E-related field of study or a college graduate in any field employed in an S&E or S&E-related occupation. The S&E workforce may also be defined by the technical expertise or training required to perform a job. Unlike information on occupational categories or educational credentials, information on the use of technical knowledge, skills, or expertise in a person’s job reflects that individual’s subjective opinion about the content and characteristics of the job.^[3] The next section provides estimates of the size of the S&E workforce using all three definitions.

Size of the S&E Workforce

Defined by occupation, the U.S. S&E workforce totals between 5.8 million and 6.0 million people according to the most recent estimates (table 3-3). Those in S&E occupations who had at least a bachelor’s degree are estimated at between 4.3 million and 5.4 million (table 3-3).^[4] By far the largest categories of S&E occupations are in computer and mathematical sciences and engineering, which together account for between three-fourths and four-fifths of all employed workers in S&E occupations (figure 3-1). Occupations in the life sciences, social sciences, and physical sciences each employ a smaller proportion of S&E workers.

As noted earlier, S&E degree holders greatly outnumber those currently employed in S&E occupations. In 2010, about 19.5 million college graduates in the United States had a bachelor’s or higher level degree in an S&E field of study (table 3-3). Almost three-fourths of these college graduates (14.5 million) attained their highest degree in an S&E field (in this chapter, these individuals are referred to as S&E highest degree holders). An individual’s highest degree is often an accurate representation of the skills and credentials that one employs in the labor market, which is why the data presented in this chapter by educational attainment are often provided for highest degree. Overall, social sciences and engineering were the most common degree fields among individuals with S&E highest degrees (figure 3-2). Of the 14.5 million S&E highest degree holders, slightly more than one-fourth attained a master’s degree (3 million) or doctorate (979,000) as their highest degree.^[5]

The majority of individuals with a highest degree in S&E reported that their job was either closely or somewhat related to their field of highest degree (table 3-3). This is despite the fact that many of these individuals were employed in occupations not categorized as S&E. This suggests that the application of S&E knowledge and skills is widespread across the U.S. economy and not just limited to S&E occupations.

The extensive use of S&E expertise in the workplace is also evident from the number of college graduates who indicate that their jobs require technical expertise at the bachelor’s degree level in S&E fields. According to the 2010 National Survey of College Graduates (NSCG), 16.5 million college graduates reported that their jobs require at least this level of technical expertise in one or more S&E fields (table 3-3). This figure is much higher than the estimated number of college graduates employed in S&E occupations (5.4 million).

Growth of the S&E Workforce

The S&E workforce has grown faster over time than the overall workforce. According to Census Bureau data, employment in S&E occupations grew from about 1.1 million in 1960 to about 5.8 million in 2011.^[6] This represents an average annual growth rate of 3.3%, compared to the 1.5% growth in total employment during this period. As a proportion of all employment, S&E occupational employment grew from 1.6% in 1960 to 4.1% in 2011.

Data from more recent years indicate that trends in S&E employment compared favorably to overall employment trends during and after the 2007–09 economic downturn. OES employment estimates from BLS indicate that the size of the S&E workforce rose slightly from 5.4 million in May 2006 to 5.8 million in May 2009 and then remained relatively steady through May 2012, reaching a level of 6 million. In contrast, the total workforce during this period declined from 133 million in May 2006 to 131 million in May 2009 and then to 130 million in May 2012. The broader STEM aggregate (including S&E technicians, S&E managers, etc.) remained relatively steady at 7.9 million in May 2012, compared with 7.8 million in May 2009 and 7.4 million in May 2006. BLS projects that between 2010 and 2020 S&E occupations—particularly computer and mathematical sciences, life sciences, and social sciences-related occupations—will grow at a faster rate than the total workforce. (See sidebar, “Projected Growth of Employment in S&E Occupations.”)

The growth in the number of individuals with S&E degrees in recent years can be examined using data from NSF’s SESTAT. The number of S&E highest degree holders employed in the United States grew from 9.6 million to 11.4 million between 2003 and 2010, with most broad fields exhibiting growth (figure 3-3). Similarly, employment in S&E occupations among college degree holders rose from 4.8 million to 5.4 million during this timeframe. Although individuals with advanced degrees beyond the bachelor’s level account for a minority of the college graduate population, between 2003 and 2010 the growth in S&E degree holders with advanced degrees generally outpaced the growth in individuals with bachelor’s degrees in most broad fields (with the exception of social sciences) (figure 3-3). (See chapter 2 for a fuller discussion of S&E degrees.)

A number of factors likely contributed to the growth in the U.S. S&E labor force over time: the rising demand for S&E skills in a global and highly technological economic landscape; increases in U.S. S&E degrees earned by women, by racial and ethnic minority groups, and by foreign-born individuals; temporary and permanent migration to the United States of those with foreign S&E educations; and the relatively small proportion of scientists and engineers retiring from the S&E labor force. The demographic sections of this chapter provide data on aging and retirement patterns of scientists and engineers as well as on S&E participation by women, by racial and ethnic minorities, and by foreign-born individuals.

Educational Distribution of Workers in S&E Occupations

Workers in S&E occupations have undergone more formal education than the general workforce (figure 3-4). Data from the 2011 ACS indicate that a larger proportion of workers in nonacademic S&E occupations (74%) hold a bachelor’s or higher degree than workers in all other occupations (30%).^[7] The proportion of workers with advanced degrees beyond the bachelor’s level is 31% in S&E occupations, compared to 11% in all other occupations. About 7% of all S&E workers (except postsecondary teachers) have doctorates.

Compared with the rest of the workforce, a very small minority of those employed in S&E occupations have only a high school degree. Many individuals enter the S&E workforce with marketable technical skills from technical or vocational schools (with or without an earned associate’s degree) or college courses, and many acquire these skills through workforce experience or on-the-job training. In information technology, and to some extent in other occupations, employers frequently use certification exams, not formal degrees, to judge skills. (See sidebar, “The U.S. S&E Workforce Without a Bachelor’s Degree” and the discussion in chapter 2.)

According to the 2010 SESTAT data, the vast majority (81%) of college graduates employed in S&E occupations have at least one S&E degree (table 3-4), suggesting that formal S&E training is the usual pathway for obtaining employment in these occupations. However, the importance of formal S&E training in the same broad field as one’s S&E occupation varies across occupational categories. Among computer and mathematical scientists, for example, less than half (44%) have a bachelor’s or higher level degree in the field of computer and mathematical sciences. The proportion is significantly higher in other broad S&E occupational categories: 73% of life scientists, 72% of physical scientists, 77% of social scientists, and 81% of engineers have a bachelor’s or higher level degree in their respective broad field. Slightly more than one-fourth (28%) of computer and mathematical scientists do not have any S&E degree. The next section presents data on the proportion of S&E degree holders who obtain employment in S&E and non-S&E occupational categories.

Occupational Distribution of S&E Degree Holders and Relationship between Jobs and Degrees

NSF’s SESTAT provides information on the degree and occupational choices of scientists and engineers in the United States, thus enabling a comparison of the interplay between degree and occupation for members of the S&E workforce with and without a highest degree in an S&E discipline. Although an S&E degree is often necessary to obtain S&E employment, the data indicate that many individuals with S&E degrees pursue careers outside of S&E. The majority of workers with S&E training who work in non-S&E jobs reported that their work is nonetheless related to their S&E training, suggesting that the application of S&E skills and expertise extends well beyond the jobs NSF classifies as S&E. (The next section, “S&E Workers in the Economy,” provides data on R&D activity of scientists and engineers employed in S&E and non-S&E occupations.)

Only about half of S&E highest degree holders are employed in an S&E (35%) or S&E-related (14%) occupation; the rest are employed in non-S&E occupations. Figure 3-5 shows the occupational distribution of the S&E workforce with S&E, S&E-related, and non-S&E highest degrees. The largest category of non-S&E jobs for S&E highest degree holders is management and management-related occupations (2.1 million workers), followed by sales and marketing occupations (995,000 workers) (appendix table 3-3). Other non-S&E occupations with a large number of S&E-trained workers include social services occupations (400,000) and college and precollege teaching in non-S&E areas (358,000). S&E highest degree holders also work in S&E-related jobs (14%) such as health occupations (532,000), S&E managerial positions (417,000), S&E technicians or technologists positions (405,000), and precollege teaching in S&E areas (196,000).

Most individuals who have S&E highest degrees but are not working in S&E occupations do not see their field of highest degree as entirely irrelevant to their work. Rather, most indicate that their jobs are either closely (35%) or somewhat (32%) related to their highest degree field (table 3-5). Among S&E highest degree holders in non-S&E managerial and management-related occupations, for example, 33% indicate that their jobs are closely related, and another 40% say that their jobs are somewhat related, to their S&E degree. Among those in social services and related occupations, 73% say that their jobs are closely related, and another 21% say that their jobs are somewhat related, to their S&E degree. Among workers in sales and marketing, 50% characterize their jobs as closely or somewhat related to their S&E degree.

Unlike members of the S&E workforce with an S&E highest degree, half or more of the S&E workforce with S&E-related or non-S&E highest degrees obtain employment in their respective broad occupational category (figure 3-5). For those with an S&E-related highest degree, the largest category of jobs is health occupations (3.2 million); for those with a non-S&E highest degree, the largest category of jobs is management and management-related occupations (862,000) (appendix table 3-3). Significant numbers of the S&E workforce with a non-S&E highest degree also work in health occupations (604,000), in precollege teaching in S&E areas (536,000), or as lawyers or judges (571,000).

The pattern of significant proportions of S&E highest degree holders obtaining employment in areas other than S&E occupations has been robust over time. SESTAT data from 1993 indicate that 36% of all scientists and engineers with S&E highest degrees were employed in S&E occupations, and the rest held positions in areas other than S&E.

The proportion of S&E highest degree holders who go on to work in S&E occupations varies substantially by S&E degree fields and levels. Individuals with social sciences highest degrees are the least likely to work in S&E occupations; these individuals primarily obtain non-S&E employment (figure 3-6). Only about 13% of social sciences highest degree holders work in S&E occupations, whereas 80% work in non-S&E occupations. Similar proportions of life sciences highest degree holders work in S&E occupations (30%) and in S&E-related occupations (26%) such as health occupations, and less than half (44%) work in non-S&E occupations. In contrast, individuals with computer and mathematical sciences (54%), physical sciences (51%), or engineering (58%) highest degrees are much more likely to work in S&E occupations. Computer and mathematical sciences highest degree holders are the most likely to obtain employment in the broad S&E field in which they were trained (51%), whereas social sciences highest degree holders are the least likely to do so (8%).

This pattern of field differences generally characterizes individuals whose highest degree is at either a bachelor’s or master’s degree level. At the doctoral level, the size of these field differences shrinks substantially (figure 3-7). S&E doctorate holders most often work in an S&E occupation similar to their doctoral field.

Whereas figure 3-7 shows the proportion of S&E degree holders employed in S&E occupations, figure 3-8 shows the proportion of S&E degree holders (regardless of occupational categories) who reported that their work is related to their S&E degree. Workers with more advanced S&E training are more likely than those with only bachelor’s level degrees to work in a job that is related to their field of highest degree. Up to 5 years after receiving their degrees, 97% of S&E doctorate holders say that they have jobs closely or somewhat related to their degree field, compared with 92% of master’s degree holders and 73% of bachelor’s degree holders (figure 3-8). In general, higher proportions of employed individuals with natural sciences and engineering highest degrees compared with those with social sciences highest degrees indicate that their jobs are related to their field of highest degree. Thus, among the SESTAT population of scientists and engineers in 2010, 75% of life sciences highest degree holders, 77% of physical sciences highest degree holders, 87% of computer and mathematical sciences highest degree holders, and 88% of engineering highest degree holders reported that their jobs were either closely or somewhat related to their highest degree field compared with 66% of social sciences highest degree holders. This is not surprising given that individuals trained in the social sciences most often obtain employment in non-S&E occupations.

The pattern of a stronger relationship between S&E jobs and S&E degrees at higher degree levels is robust across career stages, as seen in comparisons among groups of bachelor’s, master’s, and doctoral degree holders at comparable numbers of years since receiving their degrees (figure 3-8). For each group, the relationship between job and field of highest degree becomes weaker over time. Possible reasons for this decline include changes in career interests, development of skills in different areas, promotion to general management positions, or realization that some of the original training has become obsolete. Despite these potential factors, the career-cycle decline in the relevance of an S&E degree appears modest.