Working Papers

Sorting on Plan Design: Theory and Evidence from the ACA

[PDF] [Video Presentation]

Health insurance plans often differ in coverage levels and the combinations of cost-sharing attributes to achieve that level. In this paper, I show that the proliferation of plan designs can result from distortion under asymmetric information. Though optimal risk protection requires concentrating coverage in large loss states (i.e., straight-deductible plans), low-risk types signal by sorting into plans with more coverage for smaller losses. Standardizing plans to vary only along a single dimension may exacerbate welfare loss from asymmetric information. Consistent with the model, I show that a large variation in plan designs exists in the ACA federal exchange and that straight-deductible plans attract individuals with significantly higher ex-post medical spending and ex-ante risk scores. I calibrate the potential welfare effects of standardizing plan designs in the ACA when asymmetric information and consumer confusion exist.

Hospital Mergers and Service Repositioning

with Yu Ding. [PDF]

Horizontal mergers are often associated with product reshuffling, which may have important anti-trust consequences. This article shows that hospitals merging with local competitors reposition service lines after the merger. We use hospital-level service lists data from American Hospital Association 2002 - 2012. To avoid endogenous selection into mergers, we estimate difference-in-differences models comparing hospitals merged later to those merged earlier. We find that merging hospitals eliminate duplicate services without reducing patient volumes. Hospitals within a system become more differentiated in service positioning after the merger. However, there is limited evidence that repositioning leads to significant cost reductions.

Publications

Dominated Options in Health-Insurance Plans

with Justin Sydnor. American Economic Journal: Economic Policy (February 2022)

[Paper] [Online Appendix] [The New York Times Coverage]

Alternative Payment Models and Physician Treatment Decisions: Evidence from Lower Back Pain

with Yu Ding. Journal of Health Economics (December 2021). [PDF]