The O-Ring of Trust: Aggregating Entity-Specific Trust and Preventive Care

Trust is widely viewed as central to health care, yet “trust in the health care system” is not a single relationship: patients rely on many distinct entities (doctors, nurses, pharmacists, hospitals, insurers, and public health and regulatory bodies), and trust in these entities can diverge sharply. We ask how trust in a system’s constituent entities combines into overall trust, and what this composition implies for care-seeking. We develop an economic model in which overall system trust is produced from entity-specific trust through a nested CES “trust technology” that allows components to act as complements or substitutes, and we field a nationally representative U.S. survey to estimate it. In reduced form, higher trust is robustly associated with more preventive care and less avoidance, comparable in magnitude to education and income gradients. Structurally, trust is relatively substitutable across the system’s broad domains (individual providers, institutional providers and payers, and broad institutions), so high trust in some components can partially offset low trust in others. Counterfactual simulations, which we interpret as descriptive implications of the estimated model, show that among individual entities, trust in doctors is the most consequential: reducing it produces the largest declines in preventive care and the largest increases in planning no care, while comparable losses for insurers and the CDC imply smaller changes. However, a simultaneous erosion of trust across federal health institutions (CDC, FDA, and Medicare/Medicaid) carries the largest behavioral implications, underscoring the systemic stakes when trust declines broadly rather than in any single entity.