About

William Phan is an Assistant Professor of Economics at NC State University, affiliated with the Department of Economics in Nelson Hall. He holds a Ph.D. in Economics from the University of Rochester. His research and academic focus are within the field of Economics, and he is recognized as a Research Associate Professor. Further details about his specific research interests or contributions are not provided on the page.

Research topics

• Computer Science
• Political Science
• Mathematics
• Mathematics education
• Mathematical economics
• Microeconomics
• Psychology
• Economics
• Mathematical optimization
• Law
• Combinatorics
• Developmental psychology

Selected publications

• Hajj Quota Allocation as a Market Design Problem

  SSRN Electronic Journal · 2026-01-01

  preprintOpen accessSenior author
  PublisherDOI

• Variations in Female Pelvic Anatomy via MRI: A Retrospective Study at Single Academic Institution

  Uro · 2025-09-11

  articleOpen access

  Background/Objectives: Pelvic floor disorders affect up to 30% of adult females in the United States. Misdiagnosis occurs in nearly 45% to 90% of cases. Standardized pelvic anatomical measurements could improve diagnostic accuracy and treatment planning. We aimed to evaluate pelvic anatomical variations using magnetic resonance imaging (MRI). Methods: We analyzed MRI pelvic measurements from 250 women aged 20–90 years. Exclusion criteria included prior pelvic surgery (except hysterectomy), pelvic cancer, and use of alternative imaging modalities. Key measurements included anterior vaginal wall thickness (AVWT), bladder wall thickness (BWT), vaginal epithelium to bladder urothelium (VWBU), urethral length (UL), and inter-ureteral distances. A comprehensive statistical analysis was performed, including corrections for multiple comparisons. Results: While several anatomical measurements were correlated, a comprehensive analysis was performed to identify markers for clinical diagnoses. After applying Bonferroni correction for multiple comparisons, we found no statistically significant association between any of the measured anatomical parameters and a diagnosis of incontinence. Notably, an uncorrected difference in Bladder Wall Thickness (BWT) (p = 0.041) did not hold up to rigorous testing. To further assess its clinical utility, a Receiver Operating Characteristic (ROC) curve analysis for BWT as a predictor of incontinence yielded an aArea Under the Curve (AUC) of 0.19, indicating poor predictive validity. Conclusions: In this cohort, static anatomical measurements derived from MRI, including BWT, do not appear to be reliable markers for incontinence. Our findings suggest that the pathophysiology of this disorder is likely more dependent on functional or dynamic factors rather than simple static anatomical variations. Future research should focus on standardizing dynamic imaging parameters to better assess pelvic floor function.

  PublisherOA PDFDOI

• Variations in Female Pelvic Anatomy via MRI: Retrospective, Nonrandomized Study

  Preprints.org · 2025-06-24

  preprintOpen access

  Background/Objectives: Pelvic floor disorders affect up to 30% of adult females in the United States. Misdiagnosis occurs in nearly 45% to 90% of cases. Standardized pelvic anatomical measurements could improve diagnostic accuracy and treatment planning. We aimed to evaluate pelvic anatomical variations using magnetic resonance imaging (MRI).Methods: We analyzed MRI pelvic measurements from 250 women aged 20-90 years. Exclusion criteria included prior pelvic surgery (except hysterectomy), pelvic cancer, and use of alternative imaging modalities. Key measurements included anterior vaginal wall thickness (AVWT), bladder wall thickness (BWT), vaginal epithelium to bladder urothelium (VWBU), urethral length (UL), and inter-ureteral distances. Results: AVWT correlated positively with VWBU (rs = 0.542, p < 0.001) and UL (rs = 0.168, p = 0.036). Decreasing VWBU was associated with reduced BWT (rs = 0.233, p = 0.001). Women with incontinence exhibited significantly thinner BWT (2.3 ± 0.6 mm) compared to those without (3.2 ± 0.9 mm, p = 0.041). AVWT declined with age (p < 0.001), and UL to the distal urethral sphincter was shortest among Caucasian women (p = 0.016). The tissue thickness between vaginal epithelium and bladder urothelium was 9.7 mm. AVWT was greater in those < 45 years of age (4.3 mm ± 1.5) compared to those >65 years (3.5 mm ± 1.4). Conclusions: MRI-derived BWT measurements may serve as a noninvasive marker for incontinence, while AVWT and VWBU may offer insights into pelvic support. Further multicenter studies are needed to standardize imaging parameters and validate predictive anatomical markers.

  PublisherOA PDFDOI

• Partitionable choice functions and stability

  Social Choice and Welfare · 2024-07-09 · 3 citations

  articleSenior author
  PublisherDOI

• Crowding in School Choice

  American Economic Review · 2024-07-30 · 4 citations

  article1st authorCorresponding

  We consider the market design problem of matching students to schools in the presence of crowding effects. These effects are salient in parents’ decision-making and the empirical literature; however, they cause difficulties in the design of satisfactory mechanisms and, as such, are not currently considered. We propose a new framework and an equilibrium notion that accommodates crowding, no-envy, and respect for priorities. The equilibrium has a student-optimal element that induces an incentive-compatible mechanism and is implementable via a novel algorithm. Moreover, analogs of fundamental structural results of the matching literature (the rural hospitals theorem, welfare lattice, etc.) survive. (JEL D47, H75, I21, I28)

  PublisherDOI

• Increasing the representation of a targeted type in a reserve system

  Mathematical Social Sciences · 2024-02-28 · 1 citations

  article
  PublisherDOI

• Dysfunction of the aging female mouse urethra is associated with striated muscle loss and increased fibrosis: an initial report.

  PubMed · 2023-01-01

  articleOpen access

  , ACVR1/FST signaling and CTGF/TGF-β signaling) leading to a decreased striated muscle mass and an increase in fibrous extracellular matrix in the process of aging deserve further investigation for their roles in the declined urethral function.

  PublisherOA PDF

• Some characterizations of Generalized Top Trading Cycles

  Games and Economic Behavior · 2023 · 10 citations

  • Computer Science
  • Mathematical economics
  • Computer Science
  PublisherOA PDFDOI

• Family ties: School assignment with siblings

  Theoretical Economics · 2022 · 16 citations

  Senior authorCorresponding
  • Computer Science
  • Political Science
  • Computer Science

  We introduce a generalization of the school choice problem motivated by the following observations: students are assigned to grades within schools, many students have siblings who are applying as well, and school districts commonly guarantee that siblings will attend the same school. This last condition disqualifies the standard approach of considering grades independently as it may separate siblings. We argue that the central criterion in school choice—elimination of justified envy—is now inadequate as it does not consider siblings. We propose a new solution concept, suitability , that addresses this concern, and we introduce a new family of strategy‐proof mechanisms where each satisfies it. Using data from the Wake County magnet school assignment, we demonstrate the impact on families of our proposed mechanism versus the “naive” assignment where sibling constraints are not taken into account.

  PublisherDOI

• Foreign body granuloma development after calcium hydroxylapatite injection for stress urinary incontinence: A literature review and case report

  Arab Journal of Urology · 2022-11-15 · 4 citations

  reviewOpen access

  Objectives: To present a case of foreign body granuloma (FBG) development after injection of calcium hydroxylapatite as a urethral bulking agent and to review all documented cases of this phenomenon in the literature. Methods: We analyzed a new case of calcium hydroxylapatite-induced FBG. We also conducted a literature review of the PubMed, Embase, CINAHL, and Web of Science databases through March 2022. Reports were included if they contained stress urinary incontinence patients that developed an FBG after calcium hydroxylapatite injection. The cases were reviewed for presenting symptoms, patient demographics, granuloma details, and surgical treatment. Results: We screened 250 articles and included six articles between 2006 and 2015 in addition to the present case. The median age of the patients was 65.5 years (range 45-93), and all patients were female. The most common presenting symptoms and the proportion of patients affected were difficulty voiding (4/8), recurrent urinary incontinence (3/8), and dyspareunia (2/8). The median time between the first CaHA injection and discovery of the FBG was 5 months (range 1-50). The median longest dimension of the FBGs was 1.85 cm (range 1.0-3.0). The 8 masses observed were evenly distributed throughout the urethra, with 3 in the bladder neck, 2 in the midurethra, and 3 in the distal urethra. Surgical excision was the predominant management choice, with some variation in technique. Conclusions: Severe, persistent lower urinary tract symptoms after calcium hydroxylapatite injection may indicate an FBG, which has been successfully managed with surgical excision.

  PublisherOA PDFDOI

Frequent coauthors

• Umut Dur

  North Carolina State University

  4 shared

• Thayer Morrill

  North Carolina State University

  3 shared

• Christopher Purcell

  2 shared

• Patrick Harless

  University of Arizona

  2 shared

• Xiaolin Zi

  University of California, Irvine Medical Center

  2 shared

• Açelya Altuntaş

  Deakin University

  2 shared

• Ji‐Soo Kim

  Dr Youth Clinic

  1 shared

• John Ha

  1 shared