erally excluded but may be included in tabulations of graduate students because of differences in the design of the national surveys of graduate students and Ph.D.s. The behavioral and social sciences of interest include psychology, sociology, anthropology, demography, and speech-language pathology and audiology. Because this study focuses on research scientists, clinical, counseling, and school psychologists, who constitute more than 40 percent of recent Ph.D. graduates in these disciplines combined, are excluded in most tabulations.
The potential research workforce in the targeted fields is defined to include Ph.D.s who are either (1) employed full- or part-time in science or engineering, (2) unemployed but seeking work, or (3) not employed and not seeking work but not retired. Employment includes postdoctoral appointments. Because of data limitations, biomedical and behavioral Ph.D.s are included even if they are working in other scientific or engineering fields. Similar data limitations also result in the exclusion of Ph.D.s with degrees in other fields who have chosen to work in biomedical or behavioral sciences.
Those not employed and not seeking work are usually considered not to be in the labor force (and will be labeled as such). Among Ph.D.s in these fields, this group is overwhelmingly female. They move in and out of employment, and with the proportion of female Ph.D.s increasing, those not in the labor force are important to track as a potential source of trained labor. (The inclusion of this group is also the reason for using the somewhat unconventional label “potential workforce. ”)
People are assumed to enter the potential workforce when they (1) graduate with a Ph.D. in the biomedical or behavioral sciences and stay in the U.S., (2) immigrate to the U.S. after earning a Ph.D. abroad in these fields, or (3) shift from a job outside science to a job in science. The third category includes the few shifts from jobs outside science to unemployment or out of the labor force. Some additional possibilities that also involve small numbers of people will be ignored: return from retirement and, for U.S.-trained Ph.D.s. working abroad, return migration. (Excluding a return from retirement is one reason for distinguishing the retired from those not in the labor force, a number of whom return to employment.)
People are assumed to leave the potential workforce if they (1) take employment outside science, (2) retire, or (3) die. They may also emigrate, but data on emigrants are inadequate for analysis.
Figure D-1 illustrates the different groups and potential movements among them. Only the potential workforce itself and its three components—the employed, the unemployed, and those not in the labor force—will be projected, though for this purpose movement into and out of other groups has to be tracked.
Survey data provide a picture of the potential workforce and show how it has evolved and thus permit parameters to be selected for the above model based on recent history. One source is the Survey of Doctorate Recipients, a longitudinal biennial survey dating