The number of bachelor’s degrees in physics awarded annually at US institutions is at or near an all-time high—nearly double what it was two decades ago. Yet the number of first-year physics graduate students has grown much more slowly, at only around 1–2% per year. The difference in the growth rates of bachelor’s recipients and graduate spots may be increasing the competition that students face when interested in pursuing graduate study.
With potentially more students applying for a relatively fixed number of first-year graduate openings, students may need to apply to more schools, which would take more time and cost more money. As the graduate school admissions process becomes more competitive, applicants may need even more accomplishments and experiences, such as postbaccalaureate research, to gain acceptance. Such opportunities are not available equally to all students. To read about steps one department has taken to make admissions more equitable, see the July Physics Today article by one of us (Young), Kirsten Tollefson, and Marcos D. Caballero.
We do not view the increasing gap between bachelor’s recipients and graduate spots as necessarily a problem, nor do we believe that all physics majors should be expected to go to graduate school. Rather, we assert that this trend is one that both prospective applicants and those advising them should be aware of so students can make an informed decision about their postgraduation plans.
Gathering the data
For our analysis, we used data from the annual rosters of physics enrollments, which are compiled by the Statistical Research Center of the American Institute of Physics. (AIP also publishes Physics Today.) We focused on the past two decades, a period when the numbers of awarded bachelor’s degrees and PhDs rebounded from a low in the late 1990s and early 2000s. The data include enrollment and degree statistics at the departmental level and are gathered by sending annual surveys to each US physics department. More than 90% of departments respond during a typical year. To account for large-scale geopolitical and economic events that may introduce short-term fluctuations in the numbers, we computed the three-year average for each count, using the current, previous, and following years.
To determine the overall competitiveness of physics graduate school, we assumed that the number of bachelor’s degrees awarded represents the potential applicant pool and that the number of first-year graduate students in the following fall term represents the number of graduate school spots available to those degree recipients.
Although a recent AIP survey suggests that only about half of physics and astronomy seniors want to attend physics or astronomy graduate school, we used the total number of bachelor’s recipients to account for other potential applicants who are harder to quantify. For example, previous AIP surveys suggest that around 10% of first-year physics graduate students major in something other than physics or astronomy as undergraduates. They also show that 32% of first-year US graduate students wait more than five months after completing their bachelor’s degree to enroll in a graduate program. Other graduate school applicants have already completed a master’s degree or graduate coursework at a different institution.
The overall picture
Comparing the three-year national averages of the number of first-year graduate students and the number of bachelor’s degrees awarded, we find that the potential competition for spots in physics graduate programs has nearly doubled over the past two decades. In 2003 there were 0.67 graduate school spots per undergraduate physics degree (3008 first-year graduate students compared with 4504 bachelor’s degrees awarded). In 2020 there were 0.36 spots (3337 first-year graduate students compared with 9182 bachelor’s degrees awarded).
And opportunities may be even narrower for students from the US. The most recent year of data indicates that around 10% of bachelor’s physics degrees in the US are awarded to international students, whereas around 42% of physics graduate students are international.
To understand what the trend looks like for US students, we scaled the overall trend by the average percentage of US students in physics graduate school over the past two decades (55%) divided by the average percentage of physics bachelor’s degrees earned by US students over that time frame (93.7%). We did this not because graduate schools split their spots into domestic and international ones but rather to acknowledge that a significant fraction of first-year graduate students are not represented in our applicant pool.
Doing so, we find that the number of spots in physics graduate school per US physics bachelor’s degree awarded has dropped from 0.39 in 2003 to 0.21 today. In other words, for every five US undergraduate physics students, there is one graduate school spot available.
Looking only at the national picture can obscure the various routes to a graduate physics degree. Accordingly, we also examined how the number of graduate spots per bachelor’s degree has changed over time based on the institution. Even when we broke up the data according to the highest physics degree offered and whether the institution is public or private, the same basic trend of fewer spots per bachelor’s degree holds.
The institutional data do provide insights into how the gap between bachelor’s degree recipients and first-year graduate spots has widened. In the early 2000s, the annual number of students accepted into graduate physics programs at PhD-granting institutions exceeded the number of physics bachelor’s degrees conferred by those schools. Today those institutions accept only a fraction of graduate students per bachelor’s degree that they award. The trend is especially apparent for PhD-granting departments at public institutions, where the number of graduate spots per bachelor’s degree has been cut in half. That’s likely because most of the growth in physics bachelor’s degree recipients has happened at those institutions.
Examining the trend for women
Besides the number of graduate school spots, to whom those spots are going is important too. AIP’s Statistical Research Center provided us with gender data for first-year graduate students, which allowed us to examine the representation of women in the incoming classes of PhD-granting institutions over the past two decades. (Data on race and ethnicity were not available.)
Looking at the three-year averages, we find that the percentage of physics graduate school spots awarded to women has largely followed the trend of physics bachelor’s degrees awarded to women. Until recently, the fraction of women among first-year graduate students hovered around 20%. More recently, however, both the fraction of bachelor’s degrees awarded to women and the fraction of first-year graduate students who are women have been increasing.
Taken together, the results suggest that although women are still underrepresented in physics, the increasingly competitive nature of physics graduate admissions has not resulted in further underrepresentation.
Outlook and implications
The number of graduate students is inherently tied to the amount of departmental funding. With budgets unlikely in the near future to expand enough to allow a dramatic increase in the number of graduate school spots, it is unlikely that these trends will change in the near future on the graduate student side. On the potential applicant side, however, the number of physics bachelor’s degree recipients declined for the first time in nearly two decades for the class of 2021, and the number of junior and senior physics majors is also decreasing, so fewer applicants may vie for those spots in coming years.
The fact that not every person who receives a bachelor's in physics in the US can attend a US graduate school isn’t necessarily a problem, but it should give physics faculty pause. Leaders of undergraduate physics programs should be aware that many of their graduates will not attend graduate school. Departments should develop curriculums that prepare students for alternative paths and provide regular, updated information to their undergraduates to help them make informed career decisions.
Students considering graduate school should be strategic in their choice of applications, balancing the likelihood of acceptance and the time and financial resources needed to apply. Students should also be aware that they may need to apply to graduate school during multiple academic years and consider alternative opportunities in the meantime.
For their part, graduate degree–granting departments need to consider how they allocate the limited number of spots in their programs and whether that process aligns with their equity goals. In particular, departments should take steps to prevent an arms race, in which applicants need better and better CVs to get a spot.
An arms race may at first glance appear to benefit departments. As a result, they may admit students who have extensive research experience, peer-reviewed publications, or a master’s degree. But applicants from marginalized groups or who have had nontraditional paths may not have had the same opportunities as their peers. To work toward their diversity, equity, and inclusion goals, departments should evaluate students’ accomplishments in the context of the opportunities available to them, highlighting their potential for graduate success.