The Wealth–Health Gradient Across Adulthood: A Cross-National Comparative Analysis

Prior research documents a robust wealth–health gradient, yet comparative evidence is largely confined to older adults and offers limited insight into how wealth–related health inequality is patterned across adulthood and institutional contexts. Drawing on life–course perspectives on age–graded stratification and a healthcare–system typology, we examine how the wealth–health gradient varies across age groups in seven OECD countries. Using harmonized microdata from the Luxembourg Wealth Study (LWS), we pool 30 repeated cross–sections from Australia, Germany, Italy, Luxembourg, Spain, the United Kingdom, and the United States (2002–2022), yielding 450,233 adults aged 25–80. Wealth is measured as gross non–financial and financial assets (ranked into within country–year quintiles), and health is measured with self–rated health. We assess wealth–health inequality by age using Wagstaff–normalized concentration indices and country–specific OLS models with wealth–by–age interactions and covariate adjustment. Across all countries and age groups, health is consistently concentrated among wealthier individuals. Inequality typically rises from ages 25–35 to a late–midlife peak (often 56–65) and attenuates at ages 66–80, with this rise–and–fall pattern most evident in the United States, Australia, and the United Kingdom. Cross–national differences broadly align with Reibling et al.’s OECD healthcare–system typology: private systems show the steepest gradients and regulation–oriented systems more compressed gradients, yet the United Kingdom is a notable outlier, and Italy and Spain show comparatively sustained gradients into older ages. Comparing wealth–health gradients across age groups reveals systematic age–graded patterns that are central to life–course perspectives on stratification.