Sean Nicholson

· ProfessorVerified

Cornell University · Economics

Active 1997–2026

h-index44

Citations9.2k

Papers19817 last 5y

Funding$1.1M

Faculty page

See your match with Sean Nicholson — sign in to PhdFit.Sign in

About

Sean Nicholson is a professor in the Department of Policy Analysis and Management at Cornell University. He is also the Director of the Sloan Program in Health Administration and a Research Associate at the National Bureau of Economic Research. Prior to joining the PAM Department in 2004, he was a faculty member in the Health Care Systems Department at The Wharton School of the University of Pennsylvania. His academic background includes a B.A. from Dartmouth College obtained in 1986 and a Ph.D. in economics from the University of Wisconsin-Madison in 1997. His research focuses on three main areas: the causes of regional variations in medical spending, the value of new medical technologies, and innovation in the pharmaceutical and biotechnology industries. Sean Nicholson has contributed to understanding the factors influencing healthcare costs across regions, evaluating the benefits of emerging medical technologies, and analyzing industry innovation dynamics. His work is recognized within the fields of health economics and labor economics, and he has been actively involved in academic and policy discussions related to healthcare economics.

Research topics

Information Retrieval
Medicine
Computer Science
Pharmacology
Economics
Monetary economics
Emergency medicine
Internal medicine
Finance
Actuarial science
Data science
Pediatrics

Selected publications

Physician Competition: Entry and Substitution
SSRN Electronic Journal · 2026-01-01
preprintOpen accessSenior author
Publisher DOI
Strategic Selection And Pricing Power: Optum’s Acquisitions Of Ambulatory Surgery Centers And Physician Practices
Health Affairs · 2026-02-01
article
Vertical integration between insurers and providers is rapidly reshaping US health care, with acquisitions by UnitedHealth Group's Optum division playing a significant role. This study examined two dimensions of Optum's strategy: whether the physician practices it acquired shifted patients from hospital outpatient departments to less expensive ambulatory surgery centers (ASCs), and whether its ASC acquisitions affected prices charged to competing insurers. Analyzing 2013-21 Medicare claims, we found that acquisitions were not followed by a significant shift in ASC referral share. Our analysis of twenty-one acquired physician practices instead revealed a pattern consistent with strategic selection: Optum preferentially acquired practices that already had high rates of ASC use, a finding that held after we accounted for patient characteristics. Separately, using 2015-18 commercial claims, we found that Optum's acquisition of twenty-four ASCs was associated with an 11.0 percent price increase, an effect that comprised both a broad increase in facility fees and a rise in professional fees that occurred only among Optum-employed physicians. These findings highlight important issues for market competition and costs.
Publisher DOI
Physician Competition: Entry and Substitution
The Journal of Economic Perspectives · 2026-05-01
articleOpen accessSenior author
We describe competition in the physician market, focusing on how entry barriers and substitution possibilities have changed in recent decades. Regulatory caps on medical school seats and residency slots—especially for high-paying specialties—continue to ration entry, generate high returns for those who gain these slots, and direct the most academically accomplished trainees toward lucrative fields. But trained physicians increasingly compete with nurse practitioners, physician assistants, and other mid-level practitioners in the market for patients. Training of these substitutes has expanded far more rapidly than physician supply. We present key facts about the physician pipeline, a conceptual framework linking specialty earnings to entry barriers, and describe the rise of mid-level providers. These facts mean that effective competition policy in physician markets must look beyond conventional concentration measures and focus on the institutions and laws that govern who can provide medical care.
Publisher DOI
Physician Competition: Entry and Substitution
SSRN Electronic Journal · 2026-01-01
preprintOpen accessSenior author
Publisher DOI
Medicaid Expansion and Retail Pharmacy Availability
JAMA Health Forum · 2026-02-27
articleOpen access
This cohort study evaluates whether expanded Medicaid eligibility under the Affordable Care Act was associated with pharmacy availability, and how Medicaid coverage losses under the One Big Beautiful Bill Act may be associated with pharmacy availability.
Publisher OA PDF DOI
The Organization of Innovation: Incomplete Contracts and the Outsourcing Decision
American Economic Journal Microeconomics · 2025-01-01 · 2 citations
preprintOpen access
Why do firms outsource research and development (R&D) for some products while conducting R&D in-house for similar ones? An innovating firm risks cannibalizing its existing products. The more profitable these products, the more the firm wants to limit cannibalization. We apply this logic to the organization of R&D by introducing a novel theoretical model in which developing in-house provides the firm more control over the new product's location in product space. An empirical analysis of our testable predictions using pharmaceutical data concerning patents, patent expiration, and outsourcing at various stages of the R&D process supports our theoretical approach.
Publisher OA PDF DOI
The Impact of Health Insurer Acquisitions of Physician Practices on Prices and Patient Visits
Health Services Research · 2025-08-05 · 1 citations
articleOpen access
OBJECTIVE: To investigate whether the acquisition of physician practices by Optum, a subsidiary of United Health Group (UHG), influences patient volume and service prices, particularly, for patients enrolled in health insurance plans competing with UHG. STUDY SETTING AND DESIGN: We employed a novel database cataloging health insurer acquisitions of physician practices to identify those acquired by Optum-the nation's largest payvider (vertically integrated payer-provider)-from 2007 to 2023. These data were integrated with non-UHG commercial health insurance claims for practices acquired between 2015 and 2019. Using a stacked difference-in-differences design, we analyzed relative changes in prices and office visits across 12 Optum-acquired practices compared to a control group. Adjustments were made for physician profiles, practice characteristics, and calendar-year fixed effects to ensure robust estimates. PRINCIPAL FINDINGS: From 2007 to 2023, Optum acquired 44 physician practices, employing 7828 physicians by 2023. Postacquisition, we found no statistically significant average change in prices for most acquired practices relative to controls. However, the single largest acquisition was associated with a relative price increase of 4.5% (95% CI: [1.2%, 7.8%]; p = 0.02) for established patient visits. Preacquisition trends showed prices at acquired practices rising faster than controls. Additionally, Optum acquisitions were linked to suggestive declines in claim volume 1-1.5 years postacquisition, though this shift was predominantly driven by the largest acquired practice, indicating variability in outcomes across the sample. CONCLUSIONS: Optum's acquisition of physician practices did not broadly result in significant price changes for evaluation and management services provided to patients with competing insurance plans, despite higher baseline prices at acquired practices. Suggestive reductions in patient volume emerged postacquisition, but effects were inconsistent. Extended follow-up research is warranted to evaluate whether these acquisitions reshape local healthcare market dynamics over time.
Publisher OA PDF DOI
Complex implementation factors demonstrated when evaluating cost-effectiveness and monitoring racial disparities associated with [18F]DCFPyL PET/CT in prostate cancer men
Scientific Reports · 2023-05-23 · 15 citations
articleOpen access
Abstract Prostate cancer (PC) staging with conventional imaging often includes multiparametric magnetic resonance (MR) of the prostate, computed tomography (CT) of the chest, abdomen, and pelvis, and whole-body bone scintigraphy. The recent development of highly sensitive and specific prostate specific membrane antigen (PSMA) positron emission tomography (PET) has suggested that prior imaging techniques may be insufficiently sensitive or specific, particularly when evaluating small pathologic lesions. As PSMA PET/CT is considered to be superior for multiple clinical indications, it is being deployed as the new multidisciplinary standard-of-care. Given this, we performed a cost-effectiveness analysis of [ 18 F]DCFPyL PSMA PET/CT imaging in the evaluation of PC relative to conventional imaging and anti-3-[ 18 F]FACBC ( 18 F-Fluciclovine) PET/CT. We also conducted a single institution review of PSMA PET/CT scans performed primarily for research indications from January 2018 to October 2021. Our snapshot of this period of time in our catchment demonstrated that PSMA PET/CT imaging was disproportionately accessed by men of European ancestry (EA) and those residing in zip codes associated with a higher median household income. The cost-effectiveness analysis demonstrated that [ 18 F]DCFPyL PET/CT should be considered as an alternative to anti-3-[ 18 F]FACBC PET/CT and standard of care imaging for prostate cancer staging. [ 18 F]DCFPyL PET/CT is a new imaging modality to evaluate PC patients with higher sensitivity and specificity in detecting disease than other prostate specific imaging studies. Despite this, access may be inequitable. This discrepancy will need to be addressed proactively as the distribution network of the radiotracer includes both academic and non-academic sites nationwide.
Publisher OA PDF DOI
Elevated <scp>end‐of‐life</scp> spending: A new measure of potentially wasteful health care spending at the end of life
Health Services Research · 2022-10-28 · 8 citations
articleOpen access
OBJECTIVE: To construct a new measure of end-of-life (EoL) spending-the elevated EoL spending-and examine its associations with measures of quality of care and patient and physician preferences in comparison with the commonly used total Medicare EoL spending measures. DATA SOURCES AND STUDY SETTING: Medicare claims data for a 20% random sample of Medicare fee-for-service (FFS) patients, from the health care quality data for 2015-2016, from the Hospital Compare and the Medicare Geographic Variation public use file, and survey data about patient and physician preferences. STUDY DESIGN: We constructed the elevated EoL spending measure as the differential monthly spending between decedents and survivors with the same one-year mortality risk, where the risk was predicted using machine learning models. We then examined the associations of the hospital referral region (HRR)-level elevated EoL spending with various health care quality measures and with the survey-elicited patient and provider preferences. We also examined analogous associations for monthly total EoL spending on decedents. DATA EXTRACTION METHODS: Medicare FFS patients who were continuously enrolled in Medicare Parts A & B in 2015 and were alive as of January 1, 2016. PRINCIPAL FINDINGS: We found a large variation in the elevated EoL spending across HRRs in the United States. There was no evidence of an association between HRR-level elevated EoL spending and established health care quality measures, including those specific to EoL care, whereas total EoL spending was positively associated with certain quality of care measures. We also found no evidence that elevated EoL spending was associated with patient preferences for EoL care. However, elevated EoL spending was positively and significantly associated with physician preferences for treatment intensity. CONCLUSIONS: Our findings suggested that elevated EoL spending captures different resource use from conventional measures of EoL spending and may be more valuable in identifying potentially wasteful spending.
Publisher OA PDF DOI
2021 JADA Reviewers List
The Journal of the American Dental Association · 2022
- Information Retrieval
- Computer Science
- Information Retrieval
DOI