Geographic Rating Area Redesign and Health Insurance Market Outcomes: Evidences from Washington State
Abstract
This paper examines the effects of rating area redesign in the Affordable Care Act (ACA) exchange market, where insurers are mandated to offer uniform premiums to individuals of the same age within a given geographic rating area. This pricing rule and the design of the rating areas are crucial in determining market size, risk pools, and overall market dynamics. Leveraging a 2019 legislative change in Washington State as a source of exogenous variation, I investigate how rating area redesign(fragmentation) influences insurer participation, plan offerings, and premium settings. The results show a significant decline in the number of participating insurers and available plans following the redesign. Additionally, the average premiums are influenced by changes in the health risk distribution caused by redrawn lines. Using comprehensive enrollment records, I estimate the impact on consumer welfare and find that reconfiguration of rating areas reduces average annual consumer surplus by $773 per individual in affected counties, leading to an estimated annual market-wide loss of $267 million in the post-2019 period.
Presentation: MSU Applied Brown-bag seminar 2023; APPAM 2023, 2024; Southern Economic Association 2023, 2024; ASHEcon 2024
The Impact of Copay Caps on Mortality: Evidence from Diabetic Patients (with Narae Park)
Abstract
We evaluate state-level insulin copay cap policies and their impacts on diabetes mortality. As rising insulin costs create financial burdens on diabetic patients, numerous states have implemented copay caps to improve affordability. We investigate whether these policies reduce diabetes mortality among the population under 65. We exploit variation in both the staggered timing of the policy adoption and cap levels across states, and use county-level mortality data from 2018-2023 for analysis. We find that copay caps are associated with meaningful reductions in diabetes mortality, though differences by cap amounts are not statistically significant. The mortality reductions concentrate in counties with high diabetes prevalence, high poverty rates, or limited physician access, while other counties experience little change. These results suggest that the local characteristics shape their effectiveness in reducing diabetes mortality.
Presentation: ASHEcon 2024; APPAM 2024; Southern Economic Association 2024
Facilitators and Barriers to Doctor of Nursing Practice Nurse Practitioner Program Implementation: A Mixed Methods Study (with Marcy Ainslie, Mary Beth Bigley, Susan Buchholz, Shannon Idzik, and Kara Schrader). Journal of Doctoral Nursing Practice (forthcoming)