HP X LDI Research Seminar: Riley League, PhD, MPH, Assistant Professor of Finance, University of Illinois Urbana-Champaign
12:00pm - 1:00pm • Colonial Penn Center Auditorium
2026-01-29 12:00:00 2026-01-29 13:00:00 America/New_York HP X LDI Research Seminar: Riley League, PhD, MPH, Assistant Professor of Finance, University of Illinois Urbana-Champaign Fragmented Insurance and Billing Frictions: Understanding Denied Health Insurance Claims Open to Penn Affiliates Please note: Registration for this event is required. Please register here: https://share.hsforms.com/1dAXFMDm7T9CYwjJW6RBjXQ5gwp1. This event is co-sponsored with the Leonard Davis Institute of Health Economics. Billing and insurance-related activities are a dominant driver of the high administrative costs of the US health care system. However, the economics claim denials—the most visible manifestation of billing frictions—remains poorly understood. We explain why the prevalence of claim denials is an economic puzzle and investigate why denials persist in equilibrium. Using data from the Massachusetts All-Payer Claims Database, we document that denials are prevalent even for private insurers and show that these denials are largely for low-cost, routine services. We then present evidence that insurance fragmentation is a key driver of claim denials: the rate of denials spikes when enrollees change insurers, and different insurers have very different equilibrium denial rates for the same service, suggesting providers do not narrowly tailor their billing across insurers. Together, these findings highlight how fragmented insurance structures and heterogeneous coverage rules can contribute to inefficiency and waste in the U.S. health care system. Riley League is an Assistant Professor of Finance at the University of Illinois Urbana-Champaign Gies College of Business. His research interests lie in health economics and industrial organization, with a focus on how administrative burdens shape the delivery, cost, and outcomes of health care in the United States. He also conducts research on the dialysis industry, where he and his coauthors examine the significant influence of financial, regulatory, and legal incentives. He holds a courtesy appointment in the University of Illinois Department of Economics and is a Faculty Research Fellow at the National Bureau of Economic Research (NBER). Prior to joining the faculty, he was a Postdoctoral Fellow in Health and Aging Research at the NBER, following the completion of his PhD in Economics at Duke University in May 2023. Colonial Penn Center Auditorium Penn Medical Ethics
Fragmented Insurance and Billing Frictions: Understanding Denied Health Insurance Claims
Open to Penn Affiliates
Please note: Registration for this event is required. Please register here: https://share.hsforms.com/1dAXFMDm7T9CYwjJW6RBjXQ5gwp1.
This event is co-sponsored with the Leonard Davis Institute of Health Economics.
Billing and insurance-related activities are a dominant driver of the high administrative costs of the US health care system. However, the economics claim denials—the most visible manifestation of billing frictions—remains poorly understood. We explain why the prevalence of claim denials is an economic puzzle and investigate why denials persist in equilibrium. Using data from the Massachusetts All-Payer Claims Database, we document that denials are prevalent even for private insurers and show that these denials are largely for low-cost, routine services. We then present evidence that insurance fragmentation is a key driver of claim denials: the rate of denials spikes when enrollees change insurers, and different insurers have very different equilibrium denial rates for the same service, suggesting providers do not narrowly tailor their billing across insurers. Together, these findings highlight how fragmented insurance structures and heterogeneous coverage rules can contribute to inefficiency and waste in the U.S. health care system.
Riley League is an Assistant Professor of Finance at the University of Illinois Urbana-Champaign Gies College of Business. His research interests lie in health economics and industrial organization, with a focus on how administrative burdens shape the delivery, cost, and outcomes of health care in the United States. He also conducts research on the dialysis industry, where he and his coauthors examine the significant influence of financial, regulatory, and legal incentives. He holds a courtesy appointment in the University of Illinois Department of Economics and is a Faculty Research Fellow at the National Bureau of Economic Research (NBER). Prior to joining the faculty, he was a Postdoctoral Fellow in Health and Aging Research at the NBER, following the completion of his PhD in Economics at Duke University in May 2023.