Enrollment in U.S. graduate S&E programs grew for almost 20 years, reached a peak of almost 440,000 students in 1993, and then began to shrink. From 1975 to 1993, the total number of students in graduate programs increased steadily at an average annual rate of 2 percent. Subsequent declining enrollment has averaged 1 percent annually. Fewer students enrolling in engineering, mathematics, and the computer sciences account for most of this decline. Engineering, mathematics, and computer science enrollment grew at a rate of almost 4 percent annually from 1975 to 1992, but declined 3 percent annually from 1992 to 1995. While a slightly increasing number of students continues to enroll in the social and natural sciences, the annual rate of increase in these fields slowed after 1992. Trends differ when examining subfields: a look at the natural sciences shows that graduate enrollment in the physical sciences has decreased, while enrollment in the biological sciences has increased (NSF 1996e).
While there are fewer graduate students in science and engineering, U.S. students today are a more diverse group than in the past. In 1977, women represented only one-quarter of S&E graduate enrollment; by 1995, they accounted for 38 percent of enrollment. (See figure 2-13.) While women and minorities continued a decade-long trend of increased enrollment in graduate S&E programs in 1993, enrollment figures for foreign students and U.S. white males began a downward trend. (See figure 2-14.)
In 1992, foreign graduate students reversed their decade-long trend of increased S&E enrollment in U.S. institutions. They decreased their enrollment each year since then. From 1983 to 1992, the number of foreign graduate students increased over 5 percent annually. From 1992 to 1995, their numbers decreased more than 3 percent annually. (See appendix table 2-25.)
The field of engineering illustrates both decreasing enrollment and increasing diversity. The number of students enrolled in graduate programs in engineering declined from approximately 118,000 in 1992 to less than 108,000 in 1995. But 1995 enrollment included almost 1,000 more women and 1,000 more underrepresented minorities than in 1992. One factor in the increasing enrollment of minorities in graduate S&E programs may be changing demographics-the higher growth rate in the minority population relative to the white population. The approximately 10,000-person decrease in engineering students from 1992 to 1995 was primarily due to declining numbers of foreign students and U.S. white males. In 1995, the number of foreign students represented about one-third of U.S. graduate enrollment in engineering, down from a peak of 34 percent in 1992. (See figure 2-15 for the declining enrollment of foreign students in graduate engineering.)
The recent decline in foreign students is likely influenced by the increasing educational opportunities in other countries. The growing capacity for S&E graduate education in Asian countries is shown not only in the expansion of higher education institutions in Asia (see "Growth in Institutions of Higher Education in Asia"), but also in the high rate of growth in earned doctoral degrees within Asian universities. (See appendix table 2-26.)
The majority of foreign students in the United States come from a small group of countries. Twelve leading countries of origin account for over 60 percent of the approximately 450,000 foreign students enrolled in U.S. higher education. Students from Asian countries-the most significant region of origin of foreign students in U.S. institutions-come to study at both the graduate and undergraduate levels. (See text table 2-7.) Students from China and India come to study mainly at the graduate level and overwhelmingly in NS&E fields. In contrast, students from Japan enroll mainly at the undergraduate level for non-S&E fields such as business administration. Enrollments of students from South Korea and Taiwan are more equally divided among graduate and undergraduate programs. Undergraduate students from South Korea and Taiwan in U.S. institutions study mainly non-S&E fields, while the majority of South Korean and Taiwanese graduate students enter S&E fields. (See appendix table 2-34.)
Over the past two decades, the overall trends in science and engineering degrees at the master's level show an increase in the number of earned degrees throughout the 1980s, with even stronger growth in the 1990s. The recent growth is mainly accounted for by the rising numbers of earned degrees in the social sciences and engineering, with relatively stable numbers in the natural sciences, mathematics, and computer sciences.
Examining trends within each field highlights the variations among different time periods of the past 20 years. In natural science fields, after a slight downward trend in the 1980s, the number of graduate students successfully completing master's degrees increased in the 1990s. In mathematics and the computer sciences, the very strong growth rate in earned master's degrees in the 1980s (almost 8 percent annually) shifted to a more modest growth rate in the 1990s, about 2 percent. The slight downward trend in earned master's degrees in the social sciences turned around in 1989, with sharply increasing numbers of social science degrees since then. The rapid growth in engineering master's degrees after 1980 leveled off in 1989-91, increased from 1991 to 1994, and then again leveled off in 1994-95. (See appendix table 2-27.)
Over the 20-year period 1975 to 1995, males accounted for the strong growth in master's degrees in engineering, mathematics, and the computer sciences. Females were primarily responsible for the strong growth in social sciences; they also obtained a larger share of degrees in the natural sciences. However, the proportion of master's degrees earned by females increased considerably in the last two decades-not only in the natural sciences, but in engineering as well. In 1975, females earned 21.1 percent of the natural science degrees at the master's level and 2.5 percent of the engineering degrees. By 1995, females accounted for 41.0 percent of natural science degrees and 16.2 percent of engineering degrees. (See appendix table 2-27.)
In the 1990s, minority groups in the United States earned, in most cases, increasing numbers as well as increasing shares of master's degrees in S&E fields. The number of S&E degrees earned by Asian Americans consistently increased, especially in engineering, mathematics, and the computer sciences. The number of S&E master's degrees obtained by blacks grew modestly in most fields, with strong growth in the social sciences. Despite gains in individual S&E fields, the overall share of master's degrees in S&E earned by black students declined slightly from 1977 to 1995. Hispanics earned a modestly increasing number-and proportion-of degrees in the social sciences, as well as in engineering. White students showed modest growth in NS&E degrees earned in the 1990s, and strong growth in social science. Notwithstanding these gains, the share of master's degrees earned by white students in all fields declined during the 1977-95 period. (See text table 2-8 and appendix table 2-28.)
Analysis of master's degrees by citizenship shows a continuation of the trend toward a larger proportion of degrees going to foreign students in engineering, mathematics, and the computer sciences. In 1975, foreign students earned 21.8 percent of the engineering degrees and 11.3 percent of the math and computer science degrees. By 1995, foreign representation at the master's level was 33.9 percent in engineering and 34.7 percent in math and computer sciences. (See appendix table 2-28.)
However, the rate of growth of overall S&E master's degrees obtained by foreign students slowed somewhat in the 1993-95 period, primarily because of the leveling off in their earned degrees in mathematics and computer sciences. There is as yet no evidence of declining numbers of engineering degrees awarded to foreign students, even though foreign graduate enrollment in engineering decreased from 1993 to 1995 and leveled off in 1996. (See figure 2-15.)
From 1975 to 1985, the number of S&E doctoral degrees granted in the United States was relatively stable. After 1985, however, the number of such degrees grew, reaching over 26,000 by 1995. (See figure 2-16.) Large increases in the number of earned degrees occurred mainly in engineering, mathematics, and computer sciences. The number of degrees in these fields nearly doubled from 1985 to 1995. Natural science fields-particularly the biological sciences-also contributed to the rising number of degrees, with a 30 percent increase.
Male doctoral degree recipients accounted for much of the growth in engineering, mathematics, and computer sciences, while female doctoral recipients were largely responsible for the increasing number of natural science degrees.
Within the past two decades, the share of S&E doctoral degrees earned by women doubled from 15.6 percent in 1975 to 31.2 percent in 1995. The proportion has differed by field. By 1995, females earned almost half of the doctoral degrees in the social sciences and 38 percent in the biological sciences. (See appendix table 2-30.) Growth in the proportion of degrees awarded to women was greatest in engineering subfields. By 1995, women earned almost 12 percent of all engineering doctorates, and 15 to 16 percent of doctoral degrees in chemical and materials engineering.
Underrepresented minorities within U.S. universities received almost 5 percent of all S&E doctorates awarded in 1995, up slightly from 3 percent in 1977. As a group, these minorities accounted for 8 percent of earned degrees in the social sciences, 4 percent in the natural sciences, 3 percent in engineering, and 2 percent in mathematics and the computer sciences. For black Ph.D. recipients, the largest numerical increases in the past decade have been in the biological and social sciences. The largest percentage increases have been in the biological sciences and engineering. (See appendix table 2-31 and NSF 1996d.)
In the past decade, foreign students have accounted for the large growth in S&E doctoral awards in U.S. universities. The number of foreign doctoral recipients in U.S. universities doubled in S&E fields from over 5,000 in 1986 to over 10,000 in 1995. This doubling translates to an 8.2 percent average annual increase. In contrast, the rate of increase in doctoral degrees to U.S. citizens averaged only 1.9 percent annually.
Within NS&E fields, the proportion of doctoral degrees earned in U.S. universities by foreign citizens climbed from 31 percent in 1986 to 47 percent in 1994; it has since begun to level off. (See figure 2-17.) Foreign students from China, India, South Korea, and Taiwan have played a central role in this growth. In 1995, foreign doctoral recipients from these four Asian economies accounted for 59 percent of all S&E doctorates earned by foreign students (NSF 1996d). In 1995, the share of NS&E degrees earned by foreign students decreased slightly to 46 percent, mainly due to a decline in doctoral degrees earned by South Korean and Taiwanese students. Both of these economies (which are major contributors of foreign graduate students in the United States) have increased their internal capacity for graduate education in science and engineering, evidenced by the increasing number of in-country doctoral degrees in these fields. (See appendix table 2-36.)
Even as Asian students entered U.S. graduate programs in record numbers, Asian universities were expanding their own doctoral degree programs in S&E fields. In fact, the two phenomena are related. The desire to increase their within-country capacity to educate their students through the doctoral level required sending students abroad as a way of preparing more S&E faculty for expanded graduate programs within Asian universities. In the period 1988-94, the Asian effort to receive doctoral training in U.S. universities was particularly intense, as evidenced by an increase from 2,872 earned degrees in 1989 to 6,229 in 1994. The annual rate of growth in earned S&E doctoral degrees during this period was over 17 percent. This rate of growth has slowed considerably in the last few years, however.
Students from Asian countries are becoming less dependent on U.S. universities for their doctoral training. After 1993, the annual rate of increase in the number of earned S&E doctoral degrees within Asian universities greatly exceeded the growth in degrees earned by Asian foreign students within U.S. universities. (See figure 2-18.) While Ph.D. production in S&E fields is growing at a faster rate in Asian countries than in the United States, it should be noted that the base is lower. In 1995, total doctoral degrees in S&E earned in six Asian countries numbered 15,700. In that same year, U.S. universities produced over 26,000 doctoral S&E degrees; over 6,000 of these degrees were earned by foreign students from Asia. (NSF 1996e). In 1995, the number of doctoral NS&E degrees earned from universities within four Asian economies exceeded the number of such degrees earned by Asian foreign students within U.S. universities. Only for Taiwan do U.S.-earned NS&E doctoral degrees outnumber those earned within Taiwanese universities. However, in engineering, China, India, and South Korea still obtain more doctoral degrees from U.S. universities than from their home country universities. (See text table 2-9.)
Besides providing doctoral training to foreign students from Asia, U.S. higher education is also linked to expansion of Asian capacity in S&E education through institution building. Leading research universities in the United States are advising developing countries in their design of higher education in science and engineering. For example, the Massachusetts Institute of Technology has accepted an agreement to create a scientific research university in Malaysia (Sales 1997).
Until 1992, around half of the foreign students who earned doctoral degrees in S&E in U.S. universities planned to locate in the United States after completing their degrees. A significantly smaller proportion (one-third) received firm offers to remain in the United States for academic or industrial employment. The proportion of foreign doctoral recipients who plan to locate in the United States and accept firm offers differs considerably by country and region. Students from Asian countries, who are the most numerous, are the most likely to stay in the United States. In contrast, of the less numerous students from North and South American countries, fewer plan to locate in the United States.
For the period 1992-96, the percentages of foreign S&E doctoral recipients planning to remain in the United States increased: over 68 percent planned to locate in the United States, and nearly 44 percent had firm offers to do so. This recent increase in stay rates, which may be temporary, is mainly accounted for by the sharp increase in the percentage of Chinese students with firm plans to stay in the United States. In 1990, 42 percent of over 1,000 Chinese S&E doctoral recipients in U.S. universities had firm plans to stay. By 1996, 57 percent of the nearly 3,000 Chinese S&E doctoral recipients from U.S. universities had firm plans to remain in the United States. The underlying cause for this shift is the large number of Chinese students granted permanent residence status in the United States in 1992 following China's response to student demonstrations. In 1996, students from selected countries in Europe also increased their stay rates after completing advanced S&E degrees from a U.S. university, but their numbers are small in comparison to Asian countries: 61 from the United Kingdom and 75 from Germany. (See appendix table 2-37.)Among Asian countries, China and India apparently have a limited capacity to provide high-level employment to large numbers of returning recipients of doctoral degrees in science and engineering. In 1996, 57 and 59 percent, respectively, of the U.S. S&E doctoral recipients from these countries choose to accept employment in the United States. (See appendix table 2-37.) In contrast, only 24 percent of 1996 doctoral recipients from South Korea and 28 percent from Taiwan accepted employment offers in the United States. The trend in the 1990s has been for fewer doctoral recipients from these economies to remain in the United States because of within-country employment opportunities; this is particularly true of South Korean engineering doctoral recipients. (See figure 2-19.)
To a large extent, the definite plans of foreign S&E doctoral recipients to remain in the United States revolve around postdoctoral study rather than employment. Between 1988 and 1995, individuals from the five economies with the largest numbers of foreign doctoral recipients cited further study as their main reason to stay in the United States (58 percent), followed by employment in R&D (27 percent), teaching (7 percent) and other professional employment (8 percent). (See text table 2-10.)
A recent study of foreign doctoral recipients working and earning wages in the United States (Finn 1997) shows that about 47 percent of the foreign students who earned S&E doctorates in 1990 and 1991 were working in the United States in 1995. The percentages are higher in physical sciences and engineering, and lower in the life sciences and social sciences. (See chapter 3, "Stay Rates of Foreign Recipients of U.S. Ph.Ds.") These stay rates differ more by country of origin than by discipline, however. The majority of the 1990-91 foreign S&E doctoral recipients from India (79 percent) and China (88 percent) were still working in the United States in 1995. In contrast, only 10 percent of South Koreans who completed engineering doctorates from U.S. universities in 1990-91 were working in the United States in 1995. (See appendix table 2-38.)
The same study looked at foreign doctoral recipients from 1970 to 1972. Finn estimated that 47 percent were working in the United States in 1995, and that the stay rate for that group had fluctuated around 50 percent during the 15 years leading up to 1995. There is no evidence of significant net return migration of these scientists and engineers after 10 or 20 years of work experience in the United States. This does not mean that there is no significant return migration; in fact, such migration is known to occur. (See "Reverse Flow of Scientists and Engineers to Asia" later in this chapter.) However, the fairly constant stay rates indicate that any tendency of the 1970-72 cohorts to leave the United States after gaining work experience here has been largely offset by others from the same cohorts returning to the United States after going abroad.
Postdoctoral research positions in science and engineering in U.S. universities increased 5 percent annually from the mid-1980s, and continued this rate of growth until 1994. Most of the growth in the number of postdoctoral appointments, which reached almost 26,000 in 1994, can be accounted for by the expansion of research performed by universities and the concomitant increase in earned doctoral degrees. From 1985 to 1994, funding of research performed by U.S. universities increased at almost $1 billion a year in constant dollars, from a base of $10 billion. (See chapter 4.) However, in 1995 the rate of increase in the availability of postdoctoral appointments slowed considerably, dropping to only 1 percent. In that year, R&D expenditures for university-performed research also stabilized.
During the period of rapid growth in S&E postdoctoral appointments, foreign students earned an increasing proportion both of doctoral degrees and of subsequent postdoctoral appointments. From 1990 to 1994, U.S. universities provided slightly more than half of their postdoctoral appointments to non-U.S. citizens. During this period, the growth rate of domestic postdoctoral appointments was about 4 percent. However, like the recent decline of foreign graduate enrollments in science and engineering in U.S. universities since 1993, there has been a slightly smaller proportion of foreign postdoctoral appointments and a slightly increasing number of appointments to U.S. citizens, particularly in the sciences. Foreign postdoctoral recipients still receive the majority of such research positions within U.S. universities in engineering. (See appendix table 2-39 and chapter 3, "Postdoctorate Appointments.")
Mobility is a characteristic of postdoctoral researchers throughout the world, however. Foreign scientists and engineers represent approximately 50 percent of the postdoctoral pool in the United States; the United Kingdom and France have a high percentage of foreign postdoctorates as well, although the number of postdoctoral positions in these countries is much smaller. In addition, Japan is attempting to improve the quality of its basic research at universities by offering more postdoctoral fellowships for both Japanese and foreign doctoral scientists and engineers.
One indicator of mobility of S&E personnel in the world is the proportion of foreign-born faculty in U.S. higher education. The United States has been a magnet for trained scientists and engineers because of a well-developed economy able to absorb high-level personnel. (See chapter 3, "Foreign-Born Scientists and Engineers in the United States.") This section reviews data on those S&E faculty members in four-year colleges and universities who were born in another world region and whose primary job is teaching in an S&E field.The U.S. university system has been able to employ considerable numbers of foreign-born scientists and engineers. In 1993, foreign-born faculty in U.S. higher education represented 37 percent of the engineering professors and 27 percent of the mathematics and computer science teachers. (See figure 2-20.) These faculty are mainly from Asia and Europe, with the largest numbers coming from India, China, the United Kingdom, Taiwan, Canada, and South Korea. (See text table 2-11.)
In the past decade, Asian foreign students-mainly from China, India, South Korea, and Taiwan-have earned nearly 45,000 doctoral degrees in S&E within U.S. universities. (See appendix table 2-43 and text table 2-12.) Compared to these major Asian countries of origin, the number of students from Singapore and Japan earning doctoral degrees in the United States is relatively small. Japanese industries often finance advanced training of their employees in U.S. universities for one to two years, but relatively few remain long enough to complete a doctoral program (NSF 1997c).
As mentioned above, a considerable number of doctoral recipients from Asian countries have received firm offers to remain in the United States. These Asian scientists and engineers have contributed significantly to the U.S. university system. In 1993, Asian-born faculty in U.S. higher education represented 19.7 percent of the faculty in engineering, 9.6 percent in the physical sciences, and 12.5 percent in mathematics and computer sciences. (See appendix table 2-40.) They have also contributed to U.S. industry as R&D personnel and by starting new companies. Immigrant scientists and engineers make up 28 percent of the S&E labor force in the United States (NSF 1995b). Many Asian scientists working in the United States participate in communication networks with home-country scientists. The dramatic growth in Asian economies has provided U.S.-based Asian scientists and engineers with more opportunities for cooperative research and consulting (Choi 1995).
The decision of foreign doctoral recipients to remain and work in the United States or to return home relates to job opportunities in their home country. Some dynamic Asian economies are gaining the capacity to absorb high-level S&E personnel. For example, foreign doctoral recipients from Taiwan, South Korea, and Hong Kong are successfully recruited to S&E positions within their home economies. In contrast, a high proportion of foreign doctoral recipients from India and China remains in the United States, since these countries currently have a limited capacity to offer high-level S&E employment to the 14,000 scientists and 7,500 engineers from these countries who have been educated in the United States in the last 10 years. (See appendix table 2-43.)
In the 1990s, Asian-born scientists and engineers working in the United States have begun a small reverse flow from West to East. Some are attracted by new or expanded research facilities based in their home countries; these facilities are often part of the country's strong investment in R&D infrastructure as a strategy to develop indigenous high technologies. By 1992, the combined R&D investments of six Asian countries reached almost $100 billion in constant dollar terms, up from $35 billion in 1982 (NSF 1993).
Asian countries offer opportunities for high-level employment in science as well as expanding R&D budgets that can fund the majority of proposed research within these countries. Taiwan has been able to recruit senior scientists and engineers who had previously emigrated to the United States as students and young scientists. In the late 1980s, returnees with science degrees numbered between 500 and 1,000 per year. These scientists, including some Nobel prize winners, were hired in Taiwan as senior faculty for expanding graduate programs and as laboratory directors, particularly at centers of excellence such as the Synchrotron Center in Hsinchi Science Park. (see "Chinese Students Drawn Back to Asia," 1996). The increasingly large numbers of Taiwan returnees with science degrees-over 2,000 per year-are, since 1992, competing for fewer jobs; S&E positions in government and universities, except for the newly established East China University, have largely been filled with early returnees. The Taiwanese government is providing two-year postdoctoral appointments within high-technology industries to many recent returnees. These high-technology industries, however, are hiring permanently only in targeted areas in which there is a scarcity of trained S&E personnel, such as superconductivity, and solid-state industries.
Newly established Asian universities have successfully begun to recruit Western-educated scientists and engineers to expanding S&E departments. For example, the large majority of Chinese and South Korean professors in the Hong Kong University of Science and Technology (HKUST) and South Korea's Pohang University of Science and Technology received their doctoral training in the United States. In addition to the large portion of U.S.-educated faculty in the major universities of Hong Kong, former U.S. faculty are the deans and heads of almost all of S&E departments and make up a large majority of the directors of HKUST research institutes. (See text table 2-13.)
Similarly, the National University of Singapore and its attached five research centers and six independent institutes are recruiting senior scientists from the United States as deans, department heads, and laboratory directors. Many Chinese-born U.S. scientists have been attracted to Singapore's world-class facilities and equipment, high salaries, generous research funding, and opportunity to contribute to the development of the Asian region through science and technology.