Wealth on its own does not guarantee a healthy population, according to new joint research led by the University of Surrey alongside several international collaborators. Their work, which evaluates how 38 OECD (Organisation for Economic Co-operation and Development) nations are progressing towards global health benchmarks, challenges long-held assumptions about the relationship between affluence and national well-being. Published in Annals of Operations Research, the study reveals that some of the world’s wealthiest countries, including the United States and Canada, fall behind smaller and less affluent nations in meeting the United Nations’ Sustainable Development Goal 3 (SDG 3), which aims to secure healthy lives and promote well-being for all. By contrast, countries such as Iceland, Japan and Norway are shown to excel, supported by comprehensive healthcare systems and wide-ranging access to essential services.

Central to the research is a new analytical model developed in collaboration with Surrey academics, designed to measure how effectively each country transforms investment in health into tangible outcomes. These outcomes include life expectancy, disease prevention and the availability of accessible healthcare. The results indicate that nations with cohesive public health systems and those that emphasise preventive care consistently achieve better overall results for every unit of currency invested. This contrasts with countries that depend heavily on private healthcare structures, where high spending does not always translate into strong population health.

Professor Ali Emrouznejad, one of the study’s co-authors and Professor and Chair in Business Analytics at the University of Surrey, emphasised that the findings challenge simplistic assumptions about health spending. He noted that financial resources alone are not enough to secure good health outcomes, and that the strategic use of those resources is far more critical. Countries that prioritise prevention, universal coverage and social fairness, he observed, tend to outperform wealthier nations that allocate substantial sums without a coherent long-term vision.

The researchers employed a sophisticated Joint Variable Selection Directional Distance Function model, a data-driven technique that assesses how efficiently nations convert economic and health-related inputs into well-being. This model also accounted for exposure to climate-related risks, showing that countries with strong environmental health policies consistently rank higher in overall health efficiency. The inclusion of climate considerations further underscores that the pressures on modern health systems extend beyond traditional medical challenges.

The study’s conclusions underscore the need for healthcare systems that are both equitable and efficient, integrating climate resilience into their design and everyday operation. Rather than simply increasing budgets, the evidence suggests that a greater focus on preventive measures, sustainability, and universal access would yield more meaningful improvements in population health. For policymakers, the insights offer guidance on how best to allocate resources and develop strategies that deliver substantial long-term benefits.

Professor Emrouznejad highlighted that the model provides governments with a practical framework for identifying where improvements can be made. By revealing which countries make the most effective use of their resources, it points to examples others can learn from. The overarching message is that thoughtful investment, strategic planning and an emphasis on equity can lead to stronger, more resilient and more sustainable health systems, even in countries with comparatively modest levels of wealth.

More information: Ali Emrouznejad et al, Assessing health and well-being (SDG 3) in OECD countries: a joint variable selection directional distance function approach, Annals of Operations Research. DOI: 10.1007/s10479-025-06837-9

Journal information: Annals of Operations Research Provided by University of Surrey