REVIEW 4 major objections 4 minor 40 references
How large should academic departments be?
T0 review · 4 major / 4 minor · reviewed 2026-08-01 · deepseek-v4-flash
Pith's one-line read Academic departments across eight fields share one stable size range, 4 to 23 faculty, with smaller departments either growing fast or closing and larger ones shrinking only slightly.
desk verdict A careful, valuable empirical study of department size dynamics whose central organizational-ecology interpretation is undercut by an untested regression-to-the-mean null. read the letter →
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
The reading
What carries the argument
The Becker-Döring coagulation-fragmentation model, in which departments gain or lose single faculty members at size-dependent rates a_s and b_s. Assuming the fitted size distribution is the model's equilibrium, the ratio a_s/b_{s+1} equals the ratio of consecutive fitted probabilities q_{s+1}/q_s. This ratio, rescaled by the fitted mode, reproduces the empirical pattern: net coagulation below the stable range, net fragmentation within it, and near-balance above it. The shifted log-logistic/shifted log-normal fits and the geometric central range R* are the supporting objects that locate the stable range.
What would settle it
Compile annual closure and growth rates by exact department size (not binned ranges) from an independent longitudinal dataset and test whether the ratio a_s/b_{s+1} from a freshly fitted static distribution predicts the observed direction of change at each size. If the predicted crossover size (the mode) does not align with the empirical tipping point where growth turns to attrition, or if small-department growth disappears once conditioning on survival is varied, the stable-range claim would be undermined. A sharper test: simulate a null model of independent per-faculty attrition plus size-in
Extended reading notes
Core claim
The central claim is that department sizes are regulated by size-dependent processes of growth and closure: there is a stable size range R* = [4, 23), roughly one geometric standard deviation around the median, where closure risk is low and growth is balanced. Below it, departments are in a grow-or-close regime; above it, large departments are weakly pulled downward but rarely close. This pattern appears in all eight domains, with the stable range widening at the upper boundary in domains with expensive infrastructure. The paper uses fits of shifted log-logistic and shifted log-normal distributions to locate the stable range, then shows that annual size-dependent closure risks and growth rat
Load-bearing premise
The load-bearing assumption is that the measured size-dependence of growth and closure reflects genuine organizational selection, not a statistical artifact of mean reversion or boundary effects; if departments merely fluctuate around fixed sizes, small departments would appear to grow or close even under size-independent dynamics.
Editorial extensions
If this is right
- If the stable range is real, then mergers, splits, and closures are not random management events but the tail of a continuous size-regulation process, and the visible extremes are examples of the same forces.
- University administrators can expect the highest churn among departments with fewer than about four faculty; such units are not merely small but systematically unstable.
- The common rescaled dynamics imply that domain differences are reducible to a scale parameter (the mode) plus the strength of small-size coagulation; policy that shifts the mode would shift the whole distribution.
- Large departments, above roughly 23 faculty, do not face a strong ceiling: the paper finds only marginal net attrition and minimal closure risk, so unlimited growth is weakly discouraged rather than prevented.
Reading between the lines
- A natural extension would track departments' internal faculty turnover rates separately from mergers and renames to test whether the stable range arises from regulation or from selection on which departments survive.
- The model identifies only the ratio of coagulation to fragmentation, not the absolute rates; comparing against long-run faculty mobility data would let one estimate both rates and check whether large-department stability stems from low turnover (structural inertia) or from balanced hiring and attrition.
- A stationary-fluctuation alternative—departments fluctuating around fixed sizes with mean reversion—is not explicitly tested; the grow-or-close pattern could partly reflect regression toward a stable size rather than organization-level ecology, and a direct test would strengthen the claim.
- One could test the model out of sample: predict the size-dependent closure and growth curves from the static distribution of a new domain (or a later decade) and compare with observed dynamics, without refitting the dynamic parameters.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper analyzes annual sizes of 14,418 U.S. academic departments across eight domains, fitting shifted log-logistic or log-normal distributions to the cross-sectional size distribution and defining a 'central range' R* of roughly 4–23 faculty. Using year-to-year transitions, it reports that closure risk declines with size and that growth rates exceed one below R*, are balanced inside R*, and fall below one above R*, concluding that department sizes are governed by size-dependent organizational ecology rather than Gibrat's proportionate growth. A Becker–Döring coagulation–fragmentation model, parameterized from the fitted static distribution, is presented as reproducing the direction of these dynamics. The paper emphasizes commonality across domains and a 'grow-or-close' pattern for small departments.
Significance. If the central claim is correct, the paper provides a large-scale empirical case for size-dependent selection in organizations and identifies a stable size range for academic departments, with direct policy implications for departmental restructuring. The empirical work is careful: the data are extensive, the distribution-fitting procedure includes synthetic refits to assess plausibility, and the paper reports standard errors and provides code and data. The analysis also goes beyond static fits by measuring annual transitions and testing against Gibrat's law and an independent-attrition null. However, the paper's central interpretation rests on ruling out an alternative, untested stationary-fluctuation (regression-to-the-mean) null, and the Becker–Döring 'reproduction' is only an in-sample consistency check in direction, not magnitude. These issues are load-bearing for the paper's main conclusion.
major comments (4)
- [Size-dependent closure and growth, Figs. 2 and S2] The central interpretation rejects Gibrat's law and independent per-faculty attrition, but it never tests the natural null in which each department fluctuates around a latent stable size μ_i. Under such a stationary-fluctuation model, a department observed at small s is likely to be a downward fluctuation and will regress upward on average, producing g_s>1 at small sizes; being near zero also increases the chance of hitting the absorbing boundary, producing elevated c_s. This generates the exact Fig. 2 pattern—growth and closure below R*, stagnation inside, mild attrition above—without any size-dependent organizational force. The independent-attrition null of Fig. S2 does not include mean reversion, and the implied per-faculty risk growing with s is also consistent with regression to the mean. I would require a simulation or hierarchical-model test of this stationary-fluctuation null bef
- [A coagulation–fragmentation model, Eq. (8), Materials and methods] The Becker–Döring rate ratio is set equal to q_{s+1}/q_s (Eq. 8), which is the detailed-balance condition of the fitted static distribution. Its agreement with the empirical growth rates is therefore guaranteed by construction up to direction, as the paper itself acknowledges in the Materials and methods ('comparisons are limited to the direction of net change, not its magnitude'). Moreover, the mode s* used for normalization and the central range R* used for binning are both obtained from the same fitted q_s, so the claimed coincidence of the geometric and dynamic stable ranges is an in-sample comparison. Claiming the model 'reproduces department dynamics across the full size range' overstates what is shown. An out-of-sample test (e.g., fit on one time period and predict transitions in another) or a magnitude comparison would be needed.
- [Table 1 and Figure S1] For Applied Sciences, the optimized SLL/SLN fit is not a plausible draw from the data (Table 1 footnote; Figure S1 gives p≈0.03 for both SLN and SLL). The paper still includes Applied Sciences in the pooled R* and in the cross-domain dynamic comparisons. The claim of a common size distribution and common stable range across all eight domains is therefore not supported for at least one domain. The cross-domain claims should be restricted to the seven domains whose fits pass the goodness-of-fit test, or the failure for Applied Sciences should be explained and analyzed separately.
- [Size-dependent closure and growth; Discussion limitations] Closure risk is measured as any transition from s>0 to s=0, which includes renames, mergers, and splits. The Discussion acknowledges this may inflate closure risk, but the size gradient of c_s is central to the grow-or-close claim. If small departments are more likely to be renamed or merged (e.g., as part of restructuring), the measured pattern could arise without a true size-dependent closure process. I would like to see a sensitivity analysis using alternative event definitions, or at least a quantitative assessment of how many size-zero transitions are renames/restructurings versus genuine closures, before the closure-risk result is used as evidence for organizational ecology.
minor comments (4)
- [Figure 1c] The whiskers are said to indicate 90%-quantiles, but this is not defined in the text or figure legend. Please clarify what quantity the whiskers represent (e.g., 5th–95th percentiles of the fitted or empirical distribution).
- [Table S6] The caption says 'with uncertainty estimates in parentheses,' but the rendered table shows no parentheses or uncertainty values. Please correct the table or the caption.
- [Eq. (8) and surrounding text] The step 'setting n_s = q_s/q_1' is not fully explained. As written it appears to fix both the scale and the normalization of the rate ratio; a brief justification would help readers understand how the mode s* enters and why the shape of a_s/b_{s+1} is independent of the absolute normalization.
- [Abstract] The abstract says '14,000 U.S.-based departments' but the analyses use 14,418. Consider using the exact number or an explicit approximation.
Circularity Check
No significant circularity: the dynamic measurements are independent of the static distribution fit, and the Becker-Döring comparison is an acknowledged direction-only consistency check.
full rationale
The paper's central dynamical quantities are not fitted inputs. Closure risk c_s = Pr(s_{t+1}=0 | s_t=s) and growth rate g_s = s_{t+1}/(G_t s_t) are computed directly from annual department-size transitions (Materials and methods), while the SLL/SLN parameters (mode s*, central range R*) are fitted to the static median-size distribution. The 'stable range' conclusion is an empirical association between two independently measured objects, not a consequence of the fit. The Becker-Döring rate ratio in Eq. 8 is an analytic consequence of assuming the fitted q_s is the equilibrium: a_s/b_{s+1}=q_{s+1}/q_s. The paper uses it only as a direction-of-change comparison with the measured dynamics and explicitly warns that 'comparisons between the rate ratio and the empirical growth rates are therefore limited to the direction of net change at each size, not its magnitude.' Thus the BD agreement is a weak consistency check, not a fitted parameter disguised as a prediction. The possible regression-to-mean/stationary-fluctuation alternative is a substantive robustness concern, but it does not make the derivation circular: the paper's equations do not reduce to that null, and the dynamic measurements are not defined in terms of the fit. Self-citations (refs 18, 19, 33, 35) supply data categorization, hierarchy context, and fitting methodology; none is a load-bearing uniqueness claim or an answer smuggled in by citation. Overall, the derivation chain is self-contained and the central inference has independent empirical grounding.
Assumptions & free parameters
free parameters (3)
- SLL/SLN fit parameters (s0, alpha, beta; or mu, sigma) per domain =
Table S6
- Central range width (one geometric standard deviation around fitted median) =
R* = [s-, s+) with s- ~4, s+ ~23 overall
- Normalization a_s = b_{s+1} at mode s* =
unit ratio at s*
assumptions (4)
- domain assumption The observed department size distribution is stationary and representative of the equilibrium of the BD process.
- domain assumption Department size changes occur only by single-faculty gains/losses; closures/mergers/splits are represented by size-zero transitions.
- ad hoc to paper Observed annual size s_t is the true organizational size, not a noisy transient; measured size-dependence is not a regression-to-the-mean artifact.
- domain assumption Domain categorization from ref [19] is valid for these data.
Cite this review
Pith. "Pith review of How large should academic departments be?." pith.science (2026). https://pith.science/paper/SUWRPH6O
@misc{pith2026260722189,
author = {Pith},
title = {Pith review of: How large should academic departments be?},
year = {2026},
howpublished = {\url{https://pith.science/paper/SUWRPH6O}},
note = {Machine review of arXiv:2607.22189}
}
abstract
Academic departments are the primary unit of scholarship and education at universities, and they vary vastly in their sizes. However, the consequences and natural dynamics of department size are poorly understood. Small departments face disproportionate teaching and administrative overhead per faculty member, while large ones face coordination costs and thematic incoherence. Here, we characterize and model the dynamics of academic department sizes using $14,000$ U.S.-based departments in eight academic domains. Across all domains, similar broad-tailed distributions reveal a common size range from 4 to 23 faculty members, widening across domains at its upper border. Annual size-dependent closure risks and growth rates indicate that stability is greatest in this size range: below it, small departments either close or grow quickly; within it, closure risk is low and sizes stabilize; above it, large departments can persist, with marginal attrition and minimal closure risk. An analytically tractable model of size-dependent coagulation and fragmentation, informed only by the aggregated size distribution, reproduces department dynamics across the full size range. Rescaling each domain by its most stable size reveals a common regression toward the stable range across most domains. Our results establish academic departments as organizations with natural size dynamics defined by a grow-or-close pattern for the smallest departments, and a weak pressure against unlimited growth for the largest.
Reference graph
Works this paper leans on
-
[1]
WVU Board Approves Dramatic Academic Cuts to Address $45M Deficit.Higher Ed Dive.https://www.highereddive.com/news/wvu- board- approves-academic-cuts-45m-deficit/693857/(Sept
Spitalniak, L. WVU Board Approves Dramatic Academic Cuts to Address $45M Deficit.Higher Ed Dive.https://www.highereddive.com/news/wvu- board- approves-academic-cuts-45m-deficit/693857/(Sept. 15, 2023)
2023
-
[2]
Quinn, R. West Virginia’s Unprecedented Proposed Cuts Become Clear.Inside Higher Ed.https://www.insidehighered.com/news/faculty/tenure/2023/ 08/11/west-virginia-universitys-unprecedented-proposed-cuts-become- clear(Aug. 11, 2023)
2023
-
[3]
WVU Tech.Academic Transformation Academic Program Portfolio Reviewhttps: //transformation.wvutech.edu/review(2026)
2026
-
[4]
Merger of UTSA’s Demography and Sociology Programs to In- crease Access to Research Opportunities.UT San Antonio News.https://hcap
Amanda Cerreto. Merger of UTSA’s Demography and Sociology Programs to In- crease Access to Research Opportunities.UT San Antonio News.https://hcap. utsa.edu/news/2023/08/soc-dem-merge.html(Aug. 28, 2023). 16
2023
-
[5]
Melanie Lefkowitz. New Data Science, Computational Biology Departments Span Colleges.Cornell CALS News.https://cals.cornell.edu/news/2018/10/new- data-science-computational-biology-departments-span-colleges(Oct. 11, 2018)
2018
-
[6]
Gumport, P. J. & Sporn, B. inHigher Education: Handbook of Theory and Research (eds Smart, J. C. & Tierney, W. G.) 103–145 (Springer Netherlands, Dordrecht, 1999).isbn: 978-94-011-3955-7
1999
-
[7]
Perkins, J. A. Organization and Functions of the University.The Journal of Higher Education43,679–691.issn: 0022-1546 (1972)
1972
-
[8]
The Academic Department: How Does It Fit Into The University Reform Agenda?Change: The Magazine of Higher Learning31,16–27.issn: 0009- 1383 (Sept
Edwards, R. The Academic Department: How Does It Fit Into The University Reform Agenda?Change: The Magazine of Higher Learning31,16–27.issn: 0009- 1383 (Sept. 1, 1999)
1999
Show all 40 references
-
[9]
Walvoord, B. E.et al. Academic Departments: How They Work, How They Change 164 pp.isbn: 978-0-7879-5714-8 (Wiley, 2000)
2000
-
[10]
& Nielsen, M
Aagaard, K., Kladakis, A. & Nielsen, M. W. Concentration or Dispersal of Research Funding?Quantitative Science Studies1,117–149.issn: 2641-3337 (Feb. 1, 2020)
2020
-
[11]
A., Maurer, J
Hur, H., Andalib, M. A., Maurer, J. A., Hawley, J. D. & Ghaffarzadegan, N. Recent Trends in the U.S. Behavioral and Social Sciences Research (BSSR) Workforce. PLOS ONE12,e0170887.issn: 1932-6203 (Feb. 6, 2017)
1932
-
[12]
A., Thompson, H
Smith, B., Arbeit, C. A., Thompson, H. & Yamaner, M. I.Graduate Enrollment and Postdoctoral Appointments in Science, Engineering, and Health Rise, Driven Largely by Increases in the Number of Women and Temporary Visa HoldersNSF 25-316 (National Science Foundation, Jan. 21, 202...
2025
-
[13]
Gowder, C.Trends in Graduate Students and Postdocs by Field of StudyUseful Stats.https://ssti.org/blog/useful- stats- trends- graduate- students- and-postdocs-field-study(2026)
2026
-
[14]
26, 2019)
Burke, A.Science and Engineering Indicators 2020: Science and Engineering Labor Force.NSB-2019-8 (National Science Board, National Science Foundation, Sept. 26, 2019)
2020
-
[15]
Josefy, M., Kuban, S., Ireland, R. D. & Hitt, M. A. All Things Great and Small: Or- ganizational Size, Boundaries of the Firm, and a Changing Environment.Academy of Management Annals9,715–802.issn: 1941-6520 (Jan. 2015)
1941
-
[16]
& Wagner, K
Leitner, K.-H., Prikoszovits, J., Schaffhauser-Linzatti, M., Stowasser, R. & Wagner, K. The Impact of Size and Specialisation on Universities’ Department Performance: A DEA Analysis Applied to Austrian Universities.Higher Education53,517–538. issn: 1573-174X (Apr. 1, 2007)
2007
-
[17]
Gibrat, R. P. L. Les Inégalités Économiques (1931)
1931
-
[18]
& Larremore, D
Clauset, A., Arbesman, S. & Larremore, D. B. Systematic Inequality and Hierarchy in Faculty Hiring Networks.Science Advances1,e1400005 (Feb. 12, 2015). 17
2015
-
[19]
H., Zhang, S., Clauset, A
Wapman, K. H., Zhang, S., Clauset, A. & Larremore, D. B. Quantifying Hierarchy and Dynamics in US Faculty Hiring and Retention.Nature610,120–127.issn: 1476-4687 (7930 Oct. 2022)
2022
-
[20]
FitzGerald, C., Huang, Y., Leisman, K. P. & Topaz, C. M. Temporal Dynamics of Faculty Hiring in Mathematics.Humanities and Social Sciences Communications 10,247.issn: 2662-9992 (May 17, 2023)
2023
-
[21]
Zipf’s Law and the Growth of Cities.American Economic Review89, 129–132.issn: 0002-8282 (May 1999)
Gabaix, X. Zipf’s Law and the Growth of Cities.American Economic Review89, 129–132.issn: 0002-8282 (May 1999)
1999
-
[22]
Luttmer, E. G. J. Selection, Growth, and the Size Distribution of Firms.The Quar- terly Journal of Economics122,1103–1144.issn: 0033-5533 (Aug. 1, 2007)
2007
-
[23]
Hannan, M. T. & Freeman, J. Structural Inertia and Organizational Change.Amer- ican Sociological Review49,149–164.issn: 0003-1224 (1984)
1984
-
[24]
Brinkman, P. T. & Leslie, L. L. Economies of Scale in Higher Education: Sixty Years of Research.The Review of Higher Education10,1–28.issn: 1090-7009. https://muse.jhu.edu/pub/1/article/645243(1986)
1986
-
[25]
& Groot, W
Tirivayi, N., Maasen van den Brink, H. & Groot, W. N. J.Size and Economies of Scale in Higher Education and the Implications for Mergerspre-published
-
[26]
Baker, D. D. & Cullen, J. B. Administrative Reorganization and Configurational Context: The Contingent Effects of Age, Size, and Change in Size.The Academy of Management Journal36,1251–1277.issn: 0001-4273 (1993)
1993
-
[27]
N., West, E
Barron, D. N., West, E. & Hannan, M. T. A Time to Grow and a Time to Die: Growth and Mortality of Credit Unions in New York City, 1914-1990.American Journal of Sociology100,381–421 (Sept. 1994)
1914
-
[28]
& Auster, E
Aldrich, H. & Auster, E. Even Dwarfs Started Small: Liabilities of Age and Size and Their Strategic Implications.Research in Organizational Behavior8,165–198 (Jan. 1986)
1986
-
[29]
Blau, P. M. A Formal Theory of Differentiation in Organizations.American Soci- ological Review35,201–218.issn: 0003-1224 (1970)
1970
-
[30]
& Döring, W
Becker, R. & Döring, W. Kinetische Behandlung Der Keimbildung in Übersättigten Dämpfen.Annalen der Physik416,719–752.issn: 1521-3889 (1935)
1935
-
[31]
Coagulation-Fragmentation Processes222,1–20.issn: 0167-2789 (Oct
Wattis,J.A.D.AnIntroductiontoMathematicalModelsofCoagulation–Fragmentation Processes: A Discrete Deterministic Mean-Field Approach.Physica D: Nonlin- ear Phenomena. Coagulation-Fragmentation Processes222,1–20.issn: 0167-2789 (Oct. 1, 2006)
2006
-
[32]
& Hochberg, Y
Benjamini, Y. & Hochberg, Y. Controlling the False Discovery Rate: A Practical andPowerfulApproachtoMultipleTesting.Journal of the Royal Statistical Society. Series B (Methodological)57,289–300.issn: 0035-9246.https://www.jstor.org/ stable/2346101(1995). 18
1995
-
[33]
& Erwin, D
Clauset, A. & Erwin, D. H. The Evolution and Distribution of Species Body Size. Science321,399–401 (July 18, 2008)
2008
-
[34]
& Kotz, S.Statistical Size Distributions in Economics and Actuarial Sciences354 pp.isbn: 978-0-471-45716-9 (John Wiley & Sons, Oct
Kleiber, C. & Kotz, S.Statistical Size Distributions in Economics and Actuarial Sciences354 pp.isbn: 978-0-471-45716-9 (John Wiley & Sons, Oct. 10, 2003)
2003
-
[35]
Clauset, A., Shalizi, C. R. & Newman, M. E. J. Power-Law Distributions in Em- pirical Data.SIAM Review51,661–703.issn: 0036-1445 (Nov. 4, 2009)
2009
-
[36]
& Singh, S
Diyali, B., Kumar, D. & Singh, S. Discriminating between Log-Normal and Log- Logistic Distributions in the Presence of Type-II Censoring.Computational Statis- tics39,1459–1483.issn: 1613-9658 (May 1, 2024)
2024
-
[37]
A Brief History of Generative Models for Power Law and Log- normal Distributions.Internet Mathematics1,226–251.issn: 1542-7951 (Jan
Mitzenmacher, M. A Brief History of Generative Models for Power Law and Log- normal Distributions.Internet Mathematics1,226–251.issn: 1542-7951 (Jan. 1, 2004)
2004
-
[38]
H., Teukolsky, S
Press, W. H., Teukolsky, S. A., Vetterling, W. T. & Flannery, B. P. Numerical Recipes in C: The Art of Scientific Computing, Second Edition.issn: 0-521-43108- 5 (1992)
1992
-
[39]
& Price, K
Storn, R. & Price, K. Differential Evolution – A Simple and Efficient Heuristic for Global Optimization over Continuous Spaces.Journal of Global Optimization11, 341–359.issn: 1573-2916 (Dec. 1, 1997)
1997
-
[40]
Department of Education.College Scorecard DataOffice of Planning, Evalu- ation and Policy Development
U.S. Department of Education.College Scorecard DataOffice of Planning, Evalu- ation and Policy Development. June 2026.https://collegescorecard.ed.gov/ data/. 19 Supplementary Information for How large should academic departments be? 20 Data processing The Academic Analytics Re...
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