Tracing the baccalaureate origins of doctoral recipients reveals a complex landscape where massive public flagships, elite private universities, and tiny liberal arts colleges each play distinctive roles.

Analysis of NCES Survey of Earned Doctorates, 2015–2024

Every year, roughly 33,000 to 35,000 people in the United States earn doctoral degrees. They emerge from graduate programs at hundreds of universities, but they arrive at those programs from an even wider constellation of undergraduate institutions—more than 1,600, according to the National Center for Education Statistics. Where, precisely, these future scholars completed their bachelor’s degrees reveals a great deal about the structure of American higher education and the institutional pathways that propel students toward lives of research and advanced study.

Using a decade of panel data from the Survey of Earned Doctorates (2015–2024), we set out to map these pathways. The data traces each doctoral recipient back to the undergraduate institution where they earned their baccalaureate degree, broken down by discipline. When combined with institutional data on enrollment, selectivity, and institutional type, a rich and sometimes surprising portrait emerges of the college origins of the American professoriate and research workforce.

The Raw Numbers: Big Public Universities Dominate

By sheer volume, the top producers of future PhD recipients are overwhelmingly large public research universities. UC Berkeley stands in a class of its own, with 5,228 of its former undergraduates earning doctorates over the decade—roughly 523 per year. The University of Michigan, Cornell, UCLA, and the University of Florida round out the top five, each producing well over 3,000 doctoral recipients.

The dominance of public flagships is striking. Of the top 20 institutions by raw count, 14 are public universities—a testament to their massive undergraduate populations. The University of California system alone produced over 19,000 doctoral recipients across its campuses during this period, a figure that rivals or exceeds entire countries’ PhD output. The Big Ten is similarly well-represented, with Michigan, Illinois, Wisconsin, Penn State, Ohio State, Minnesota, and Purdue all placing in the top 25.

Among privates, the usual suspects appear: Harvard, MIT, and the University of Chicago all crack the top 25. But so does a perhaps less expected name—Brigham Young University, Provo, which ranks ninth overall with 2,863 doctoral recipients, ahead of Penn State, Ohio State, and every Ivy League institution. BYU’s presence is driven partly by its large enrollment (~34,000 undergraduates) and partly by a campus culture that strongly emphasizes graduate education and research as career pathways. Its PhD output is remarkably broad-based: it ranks among the top producers in engineering, biological sciences, education, psychology, the humanities, social sciences, and even business.

Brigham Young University ranks 9th nationally in raw PhD production—ahead of every Ivy League school except Harvard—and is the single largest feeder into business doctoral programs in the country.

Adjusting for Size: Small Colleges Punch Far Above Their Weight

Raw counts, of course, reward size. A university with 40,000 undergraduates will naturally produce more PhD recipients in absolute terms than a college with 1,500, even if the smaller school sends a far greater share of its graduates on to doctoral work. To control for this, we calculated a per-capita rate: the number of doctoral recipients per 1,000 current undergraduates over the decade.

The results dramatically reshape the rankings. Caltech leads with an extraordinary rate of 891 doctoral recipients per 1,000 undergraduates—a reflection of its tiny enrollment (under 1,000 students) and nearly singular focus on scientific research. Harvey Mudd College, another tiny STEM-focused institution, follows at 509. MIT ranks third at 487, and then comes Swarthmore College—a liberal arts college with no engineering school to speak of—at a remarkable 481.

The per-capita top 25 is almost entirely composed of two types of institutions: highly selective private research universities (Harvard, Princeton, Yale, Chicago, Stanford) and elite liberal arts colleges (Swarthmore, Carleton, Williams, Haverford, Pomona, Grinnell). Not a single public university appears. This is a stunning inversion of the raw rankings and suggests that while public flagships produce the most PhDs in aggregate, the most intensive “PhD factories” on a per-student basis are the small, selective liberal arts colleges and private research universities.

The Liberal Arts College Pipeline

The prominence of liberal arts colleges in the per-capita rankings is one of the most consistent findings in studies of doctoral production, and the latest data confirms the pattern emphatically. Carleton College (399 per 1,000), Reed College (364), Williams (340), Haverford (333), Pomona (323), and Grinnell (319) all produce PhDs at rates that rival or exceed those of the Ivy League.

These institutions share several characteristics that likely drive their high rates: small class sizes, close faculty-student mentoring relationships, an undergraduate research culture, and student bodies that are self-selected for intellectual curiosity and academic ambition. The liberal arts model—broad-based education with deep engagement in a major field—appears to be especially effective at preparing students for the rigors of doctoral study.

What Drives PhD Production? Selectivity, Size, and Control

By merging the doctoral production data with institutional characteristics from NCES, we can examine how broad institutional attributes correlate with PhD output. Three variables stand out as especially predictive: selectivity, institutional size, and public/private control.

The relationship between selectivity and per-capita PhD production is dramatic and roughly monotonic. Institutions classified as “Most Selective” produce doctorates at an average rate of 252 per 1,000 undergraduates—roughly five times the rate of “Moderately Selective” ones (53). Less selective institutions average about 49 per 1,000. Selectivity is, of course, a proxy for many things at once: student ability, institutional resources, campus culture, faculty research engagement, and peer effects. But whatever the underlying mechanisms, the gradient is steep and consistent.

Public and private institutions tell different stories depending on the metric. Public universities in our matched sample account for about 100,000 doctoral recipients over the decade—well over 60% of the total—but average only 57 PhDs per 1,000 undergraduates. Private institutions contribute fewer total PhDs (~64,000) but average 207 per 1,000, nearly four times the public rate. This divergence reflects the fundamental structural difference: public universities educate vastly more students, while private institutions—especially the highly selective ones—channel a much greater proportion of their students toward doctoral study.

Hidden Gems: PhD Pipelines Beyond the Elite

The preceding analysis might suggest that PhD production is an exclusive province of the most selective institutions. It is not. When we filter the data to include only institutions classified as “Less Selective” or “Moderately Selective”—schools with acceptance rates ranging from 40% to well over 90%—a number of institutions emerge with PhD production rates that are impressive by any standard.

Spelman College tops this group with a per-capita rate of 147 PhDs per 1,000 undergraduates—a figure that would place it ahead of Yale, Brown, and Duke in the overall per-capita rankings. Spelman achieves this despite a 25% acceptance rate that, while competitive, falls in NCES’s “Less Selective” classification. Its success reflects a decades-long institutional commitment to preparing Black women for careers in science, medicine, and academic research.

Morehouse College (86 per 1,000, 44% acceptance), Xavier University of Louisiana (71 per 1,000, 69% acceptance), and Hampton University (71 per 1,000, 62% acceptance) further demonstrate the distinctive role that HBCUs play as PhD pipelines. Xavier is particularly noteworthy: it produces more Black medical students than any other institution in the country, and its graduates go on to earn doctorates in the biomedical sciences at extraordinary rates. These institutions, none of which are classified as “Most Selective” or “Extremely Selective,” consistently produce doctoral scholars at rates that rival or exceed their far more selective peers.

Among large public universities, the picture is equally telling. The University of Illinois at Urbana-Champaign (90 per 1,000, 42% acceptance) and the University of Wisconsin–Madison (80 per 1,000, 45% acceptance) lead this group, but the real surprises come farther down the selectivity ladder. Michigan State University, with an 85% acceptance rate, produces 2,215 doctoral recipients over the decade—more than Princeton, Yale, or Stanford. The University of Kansas (93% acceptance rate) produces over 1,100. Iowa State University (89% acceptance) and the University of Iowa (84% acceptance) each contribute well over 1,000. These are not institutions typically associated with elite academic pathways, yet they function as major arteries in the doctoral pipeline.

UC Santa Cruz deserves special mention: despite a 66% acceptance rate and enrollment of only 18,000, it produces PhDs at a rate of 79 per 1,000—higher than many institutions twice its size and half its acceptance rate. Its strong research culture and proximity to the wider UC research ecosystem likely play a role.

Michigan State, with an 85% acceptance rate, produces more future PhD recipients than Princeton, Yale, or Stanford. The University of Kansas, accepting 93% of applicants, contributes over 1,100 doctoral scholars.

Brigham Young University Provo, classified as “Moderately Selective” with a 68% acceptance rate, produces PhDs at an astonishing rate of 89 per 1,000 students—driven by its vast enrollment and cultural emphasis on academic and professional achievement. It leads the nation in business PhD production by a wide margin and ranks in the top 10 for several other fields.

These patterns carry an important implication: the doctoral pipeline depends heavily on institutions that are accessible to a broad cross-section of students. If doctoral programs drew only from the most selective colleges, the pipeline would be dramatically narrower. The large, moderately selective public universities and the mission-driven HBCUs serve as essential on-ramps, channeling thousands of students from diverse backgrounds into academic and research careers.

The Disciplinary Landscape: Who Produces PhDs Where?

The picture becomes even more nuanced when we disaggregate by discipline. Different types of institutions dominate different fields, and the patterns reveal the varied strengths of the American higher education ecosystem.

Engineering is dominated by a predictable set of technically oriented universities. Georgia Tech leads the nation, followed closely by Berkeley, Illinois, Purdue, and MIT. These five alone account for over 4,000 engineering doctoral recipients. The pipeline from undergraduate engineering programs to doctoral programs is tightly concentrated in a handful of elite technical universities.

Computer and information sciences shows a similar but even more concentrated pattern. Berkeley, MIT, and Carnegie Mellon form a clear top tier, trailed by Illinois, Michigan, and Cornell. The emergence of Harvard and Princeton in the CS top 10—institutions not traditionally known as “engineering schools”—reflects the broadening appeal of computing as an intellectual discipline beyond its engineering roots.

Biological and biomedical sciences, the largest single field, sees Berkeley once again at the top, but the rest of the list is notably different from engineering. Cornell, UC Davis, Wisconsin, and UC San Diego—all major research universities with strong life-sciences programs—dominate. The biological sciences draw from a broader base of institutions than engineering does.

Humanities and arts present a markedly different profile. Berkeley still leads, but the rest of the top 10 is strikingly weighted toward elite privates: Yale, Harvard, Chicago, NYU, and Columbia all rank among the top producers. BYU, notably, ranks eighth—a reflection of its emphasis on language study and cultural engagement tied to its missionary program. The humanities remain the most “elite-institution-heavy” field in terms of doctoral feeder patterns.

Mathematics and statistics show perhaps the most extreme concentration at the top. Berkeley, Chicago, MIT, UCLA, and Princeton account for a disproportionate share of future math PhDs, with Caltech also making a strong showing. This concentration likely reflects the relatively small number of institutions with the depth of undergraduate mathematics instruction needed to prepare students for doctoral-level work in the field.

Trends Over Time

Total doctoral production in the United States has remained remarkably stable over the past decade, hovering between 31,000 and 35,000 per year. The notable exception is 2021, when production dipped to about 30,800—almost certainly a delayed effect of the COVID-19 pandemic, which disrupted research timelines and degree completion across the country. By 2022, production had rebounded, and 2024 saw the highest total of the decade at nearly 34,800.

Beneath this surface stability, significant shifts are underway across fields. Engineering has seen the most pronounced growth, rising from 3,814 doctorates in 2015 to 4,657 in 2024—a 22% increase. Computer and information sciences has grown even faster in percentage terms, surging 52% from 670 to 1,016, reflecting the explosive demand for computing talent. Biological and biomedical sciences, already the largest field, has also expanded steadily, reaching nearly 7,000 doctorates in 2024.

Other fields have moved in the opposite direction. Humanities and arts doctorates have declined from 4,115 in 2015 to 3,108 in 2024—a 24% drop that mirrors well-documented enrollment declines in humanities undergraduate programs. Education has similarly contracted, from 3,917 to 3,437. Social sciences have also slipped, declining 11% over the decade. These divergent trends suggest that the American doctoral landscape is slowly but meaningfully shifting toward STEM fields and away from the humanities and social sciences.

Noteworthy Institutional Stories

HBCUs as PhD Pipelines

Historically Black Colleges and Universities have long played an outsized role in producing Black doctoral recipients, and the data bears this out. Howard University leads HBCUs with 462 doctoral recipients over the decade, followed by Spelman College (381), Florida A&M (347), Hampton University (263), and Morehouse College (234). Spelman’s figure is particularly notable given its small enrollment (~2,200), placing it among the most productive institutions per capita in the nation. Xavier University of Louisiana, famous for its pre-medical pipeline, contributes 185, a disproportionate number of whom go on to earn doctorates in the biomedical sciences.

Women’s Colleges

Women’s colleges continue to punch above their weight. Wellesley (646 PhDs), Smith (616), Mount Holyoke (559), and Barnard (555) all rank among the most productive small institutions in the country. Bryn Mawr (384) and Spelman (381, both a women’s college and an HBCU) round out the group. These institutions have historically been especially effective at channeling women into fields where they have been underrepresented, including the sciences, and that tradition clearly persists.

The UC System: A National Research Engine

The University of California system deserves special mention as a collective. Across its nine undergraduate campuses, the UC system produced over 19,100 doctoral recipients during the decade—far more than any other university system. Berkeley alone accounts for 5,228, but every campus contributes meaningfully: UCLA (3,262), UC San Diego (2,588), UC Davis (2,374), UC Santa Barbara (1,605), UC Irvine (1,568), UC Santa Cruz (1,419), UC Riverside (841), and even the youngest campus, UC Merced (220), established only in 2005.

Conclusion: Two Parallel Stories

The data reveals two parallel stories about who produces America’s PhDs. In absolute terms, the story is about scale: large public research universities—especially the UC system, the Big Ten, and flagship campuses across the Sun Belt—produce the vast majority of doctoral recipients simply because they educate the vast majority of undergraduates. These institutions are the workhorses of the American research pipeline.

But on a per-student basis, the story is about intensity: small, highly selective liberal arts colleges and elite private research universities channel a far greater share of their graduates toward doctoral study. Caltech, Harvey Mudd, Swarthmore, Carleton, Reed, and Williams send students to PhD programs at rates that dwarf even the most productive publics.

And between these two poles lies a third story—the story of the hidden gems. HBCUs like Spelman, Morehouse, and Xavier produce PhDs at rates that rival or exceed far more selective institutions, reflecting deep institutional commitments to academic excellence and mentorship. Large, accessible public universities like Michigan State, Iowa State, Kansas, and New Mexico serve as critical on-ramps to doctoral education for students who might never have considered it otherwise.

All three stories matter. The volume story ensures that doctoral programs have enough students to sustain the nation’s research enterprise. The intensity story shows where the per-student investment in cultivating future scholars is highest. And the hidden-gems story reminds us that the pipeline’s health depends not only on the most prestigious institutions but on the continued vitality of a diverse ecosystem—one that includes HBCUs, women’s colleges, accessible publics, and small liberal arts colleges, each making distinctive and indispensable contributions to the nation’s intellectual life.

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Data Sources & Methodology

PhD production data from the National Center for Education Statistics, Survey of Earned Doctorates (2015–2024). Institutional characteristics from NCES institutional data panels. Per-capita calculations use the most recent reported undergraduate enrollment figures. Selectivity classifications follow NCES definitions. Institutions are matched across datasets using name reconciliation; some institutions may not appear in the per-capita analysis if they could not be matched. Per-capita rates are calculated as total PhDs (2015–2024) per 1,000 current undergraduates—an approximation that uses a 10-year cumulative count against a snapshot enrollment figure.