Healthy self-interest? Health dependent preferences for fairer health care

• We test how health affects preferences for healthcare financing fairness. • Novel IV strategy uses BCG vaccination timing across 22 countries ( N = 73,452). • Healthier individuals show 11 % and 8 % higher support for fair access and financing. • Effects operate through economic pathways: health improves income and employment. • Health improvements may generate stronger support for equitable health policies. Health status can alter individuals' social preferences, including individuals' preferences regarding a fair financing of health care. If individuals follow a healthy self-interested rationale , health improvements can weaken individuals' support for fairer health care financing, insofar as they perceive a reduced need for healthcare. Conversely, healthier people might anticipate facing greater opportunity costs if their health declines in an unfairly funded system, and hence may endorse fairer financing in anticipation of future health challenges—which we label as the ' unhealthy self-interest ' hypothesis. We draw on a dataset of 73,452 individuals across 22 countries and a novel instrumental variable strategy that exploits variation in health status resulting from cross-country and cohort-specific exposure to the national childhood Bacillus Calmette–Guérin (BCG) vaccination schedules. We document causal evidence consistent with the unhealthy self-interest hypothesis , namely that better (worst) health increases (reduces) preferences for a fairer health care system. We estimate that a one-unit increase in self-reported health increases support for fair health care access by 11 % and the willingness to support fair financing by 8 %. Our findings suggest that improving population health may give rise to stronger support for interventions to improve equitable health system access and financing.