Doctoral Population in the Sciences and Engineering
Distribution by Field
The estimated population of science and engineering doctorates in 1995 was 542,500. For this project, the population was defined to include Ph.D.s who earned their degrees in a science or engineering field from a U.S. institution between January 1942 and June 1994 and who were age 75 or younger and residing in the United States in April 1995.
- Twenty percent of the science and engineering Ph.D. population was composed of doctorates in biological sciences (see Table 1).
- The next largest components were engineering doctorates (16 percent), psychology doctorates (15 percent), and social science doctorates (14 percent).
Demographic characteristics of science and engineering Ph.D.s, including gender, race, age, and citizenship are described in this section (see Tables 2 and 3).
- Women comprised 22 percent of the U.S. population of science and engineering doctorates in 1995.
- The fields of health sciences and psychology had the highest representation of women (51 and 42 percent, respectively). The fields with the lowest proportion of women were engineering and physics/astronomy (5 and 6 percent, respectively).
- The proportion of female science and engineering Ph.D.s has grown with each successive cohort. Only 8 percent of the group that earned its doctoral degrees more than 25 years earlier were women, while 34 percent of the doctorates from the most recent 5-year cohort were women (see Table 3).
Race/Ethnicity (regardless of citizenship status)
- The population of science and engineering doctorates was 84 percent white, 12 percent Asian, 2 percent black, 2 percent Native American, and less than 1 percent Hispanic.
- Asians comprised 29 percent of the doctorates in computer sciences and engineering.
- The highest concentrations of blacks were in health and social sciences, both 4 percent.
- The racial/ethnic composition of science and engineering Ph.D. cohorts changed over time as each successive cohort included a higher proportion of Asians, Native Americans, and blacks. Of the doctorates who earned degrees more than 25 years earlier, 6 percent were Asian; for the most recent 5-year cohort, the proportion who were Asian was 22 percent. Looking at these same two cohorts, the proportion of doctorates who were Native American increased from 1 to 4 percent, and the proportion who were black increased from 1 to 3 percent.
Age in 1995
- Of all science and engineering doctorates, 42 percent were age 44 or younger. Doctorates age 55 or older accounted for 25 percent of the population.
- The youngest doctorates were in computer sciences: 81 percent were age 44 or less. Chemistry had the highest proportion of doctorates age 55 or older (31 percent).
Year of Doctorate
- About 7 percent of all science and engineering doctorates received their degrees before 1960. Another 44 percent were earned between 1960 and 1979, and 50 percent were earned after 1979.
- Fifty-one percent of the degrees in computer sciences were earned since 1989, due primarily to the burgeoning number of programs in that field. A relatively high proportion of health science doctorates were also earned within the most recent 5 years-30 percent, compared with 19 percent for science and engineering doctorates overall.
- Thirteen percent of chemistry doctorates received their degrees before 1960, the highest proportion by field, compared with 7 percent of science and engineering doctorates overall.
- Eight percent of science and engineering doctorates were foreign citizens in 1995 (including both permanent and temporary residents).
- Computer sciences and engineering had the highest proportions of foreign citizens, 28 and 16 percent, respectively. The lowest proportion (2 percent) was in psychology.
- Foreign citizens comprised 24 percent of science and engineering doctorates earned within the most recent 5 years.
 Appendix D provides a list of detailed science and engineering Ph.D. fields and shows how they were grouped into the broad fields used for analysis in this report.