F

Minimal Support Levels

The goal of this appendix is to estimate the minimum level of support needed for individual investigators, and more globally to maintain the flow of young people into the field of biological physics. The analysis starts with the basic ingredients and then addresses how these come together to define minimal effective grant sizes for individual investigators and a minimum level of support for the field as a whole. All estimates are based on publicly available data, as indicated.

INGREDIENTS

Faculty.

At all but a handful of U.S. institutions, faculty receive a salary only for the academic year. Being active in research, and mentoring students and postdoctoral fellows, means collecting a summer salary from research grants. Faculty compensation varies widely, but the American Association of University Professors (AAUP) surveys salaries and parcels out the results by institutional categories.¹ What is most relevant to this discussion are the 227 doctoral (AAUP Category I) institutions; analysis is focused on the professorial ranks, since lecturers and instructors seldom serve as PhD advisers. A summary of these data can be found in Table F.1. Support for faculty includes fringe benefits, which again vary widely across institutions. The AAUP reports that Category I institutions’ spending on retirement and

___________________

¹ See Tables 1 and 7 in American Association of University Professors, 2020, The Annual Report on the Economic Status of the Profession, 2019-20, https://www.aaup.org/2019-20-facultycompensation-survey-results.

medical benefits is an average of 21.8 percent on top of salaries,² and this provides an estimate of fringe benefit costs to grants. The result is that 2 months of summer salary for an average faculty member is a direct cost of $34,100 per year. This likely is an underestimate, since science faculty have above-average salaries at most institutions, and because research in biological physics is not distributed uniformly across the Category I institutions.

Students.

Supporting a PhD student means paying a modest salary (stipend) so that the student can be free to focus on their research, and compensating their host institution for the cost of the student’s education. Making estimates here is especially challenging because stipends and tuition vary widely across institutions. A benchmark is provided by the National Science Foundation (NSF) Graduate Research Fellowship Program,³ which sets a stipend of $34,000 per year and a “cost of education allowance” of $12,000 per year.

Travel.

Doing research means engaging with the community. Although there are many ways to accomplish this, one important component is attendance at one scientific conference per year. For concreteness this is assumed to be the American Physical Society (APS) March Meeting. This cost has three components: (1) lodging, meals, and incidental expenses for 5 full days, taken from the per diem rates set by the General Services Administration⁴ and averaged over the locations of the March Meeting in the decade 2011–2020; (2) meeting registration fees for students and faculty, taken from the APS (pre-pandemic); (3) travel, set very roughly at $500 per person round trip. A summary is in Table F.2.

TABLE F.1 Average Academic Year Salaries at PhD-Granting Institutions, by Rank

SOURCE: Data from the AAUP faculty compensation survey.

___________________

² See Tables 8 and 9 in American Association of University Professors, 2020, The Annual Report on the Economic Status of the Profession, 2019-20, https://www.aaup.org/2019-20-facultycompensation-survey-results.

³ National Science Foundation, “Graduate Research Fellowship,” https://www.nsfgrfp.org.

⁴ General Services Administration, “Per Diem Rates,” https://www.gsa.gov/travel/plan-book/per-diem-rates.

TABLE F.2 Costs of Attending American Physical Society March Meeting

SOURCE: Registration fees from APS; lodging, meals and incidentals from GSA per diem, 5 days averaged over meeting locations 2011–2020.

Indirect costs.

Grants in support of research provide support for facilities and administrative costs, also known as indirect costs or “overhead.” This is added as a percentage of (qualifying) direct costs to cover infrastructure and other costs in the background of the research, and the percentage is negotiated by each institution with the federal government. These rates are available publicly by searching for “F&A rates” with the university’s name. The committee assessed these rates for institutions listed in the top 100 doctoral programs in physics, focusing on those with identifiable biological physics groups on their departmental websites; results are summarized in Figure F.1. The average indirect cost rate is 56.1 percent.

Postdoctoral fellows.

In physics, half of PhD students go on to postdoctoral research positions, and in 2015–2016 their median starting salary was $50,000 per year at universities and $65,000 per year at government laboratories; the split between these group is 75/25.⁵ Since 2015–2016 there has been 10.8 percent inflation,⁶ so an estimate of current median postdoctoral salaries is $60,000. As with faculty, fringe benefits are added on top of salaries; the same 21.8 percent is taken as an estimate.

A MINIMAL GRANT

Table F.3 is the budget for a minimal effective grant: 2 months of summer salary for a faculty member, stipend and cost of education for one student, travel to attend the APS meeting, and indirect costs. This is a very conservative estimate; notably, this analysis does not include any costs of actually carrying out the research, which for experimental efforts can be substantial, nor does it include the costs of

___________________

⁵ P. Mulvey and J. Pold, 2019, Physics Doctorates: One Year After Degree, American Institute of Physics, https://www.aip.org/statistics/reports/physics-doctorates-one-year-after-degree-2016.

⁶ See the “US Inflation Calculator,” with data from the Bureau of Labor Statistics, https://www.usinflationcalculator.com.

infrastructure, which might range from computing to specially built experimental apparatus. Obviously many research projects also need the intellectual effort of more than just one student.

Despite this conservatism, this minimal grant ($123,736 per year) is essentially equal to the median annual award from NSF ($122,600 per year, see Appendix E). If one replaces the average faculty member with an assistant professor, the total drops slightly but remains above the level of the CAREER award.

SUPPORTING THE FIELD AS A WHOLE

As explained in Chapter 8, there has been tremendous growth in the number of physics students who do their thesis research on problems in biological physics; this number now is more than 150 per year. The goal of this analysis is to provide an estimate of the minimum support required to nourish this flow of young people into the field.

To begin, physics PhD programs typically take 6 years to complete, divided roughly into 2 years of coursework and 3 to 4 years of focused research activity. Producing 150 new PhDs each year thus means supporting ~500 students in steady state. As noted above, half of the PhD students in physics go on to postdoctoral research positions. While postdoctoral positions once were 2 or 3 years in duration, 4 to 6 years is now more common. This lengthening of postdoctoral periods has been led by the biomedical research groups, and many young biological physicists are competing with people from these groups as they look for their next positions, so this creates pressure on the community. Assuming that postdoctoral terms average 5 years, and with 150/2 = 75 new people each year, this gives a steady state

TABLE F.3 A Minimal Research Grant Budget, Supporting Faculty Summer Salary and One PhD Student

TABLE F.4 Components of a Minimal Annual Budget to Support the Entire Biological Physics Community, Focusing on the Flow of Young People into the Field

NOTE: APS = American Physical Society.

community of 375 postdoctoral fellows. The committee estimates that these PhD students and postdoctoral fellows are being mentored by ~250 faculty members, which is roughly consistent with the number of distinct principal investigators represented in the Physics of Living Systems program over the decade 2010–2019. If these estimates are correct, then the core U.S. research community in biological physics consists (very) roughly of 500 PhD students, 375 postdoctoral fellows, and 250 faculty, or nearly 1,200 people. This is roughly consistent, for example, with the number of presentations on biological physics at the APS March Meeting.

These estimates of community size can be combined with the data above on the costs for supporting different components of the community, and results are summarized in Table F.4. The total depends on how support for PhD students is divided between training grants and research grants, but is in the range of $83 million to $92 million per year. It is emphasized again that this would support only the primary research personnel. Not included are the costs of research facilities, equipment and supplies, technical or administrative support staff, travel for collaboration, and so forth.

It also is possible that this discussion substantially underestimates the size of the field. As noted in Figure 8.2, if one includes both biological physics as a field of physics and biophysics as a field of the biological sciences, the enterprise is twice as large.