Salpy Kanimian

"Spatial Disparities, Selection, and Segmentation in Health Insurance". JOB MARKET PAPER 

Abstract: Most U.S. means-tested programs use uniform eligibility thresholds that ignore regional cost-of-living differences. I study whether indexing eligibility to local costs improves coverage and targeting in Medicaid and health insurance marketplaces—two adjacent programs serving low-income individuals without employer insurance. I develop and estimate a model where the regulator sets eligibility rules, insurers compete on price and quality, and consumers choose or are assigned to plans. I find that adjusting eligibility thresholds for cost-of-living creates competing effects: it improves coverage by crowding low-income families into insurance in high-cost areas, but also reshuffles risk pools across both programs in ways that change premiums and plan quality. Counterfactual simulations using administrative data from California show that partial cost-of-living indexing yields higher welfare per public dollar than either uniform thresholds or full indexing. These results demonstrate how eligibility design interacts with market structure and insurer incentives in segmented health insurance systems.