In Health Economics, LDI Fellow Amelia Bond and colleagues raise important questions about potential positive effects of provider and insurer concentration on primary care appointment availability for new Medicaid patients. The study assesses whether the two health care industry trends of expanding Medicaid and greater integration and consolidation among insurers and providers may have implications for each other.
Using “secret shopper” data on primary care physicians' real-world behavior, the authors observed provider willingness to accept new privately insured and Medicaid patients across 10 states. They combined this measure with detailed information on physician and commercial insurer market structure.
They find that insurer and provider concentration are each positively associated with relative improvements in appointment availability for Medicaid patients. The former is consistent with a smaller price discrepancy between commercial and Medicaid patients and suggests a beneficial spillover from greater insurer market power. The findings for physician concentration do not align with a simple price bargaining explanation, but do appear driven by physician firms that are not vertically integrated with a health system.