Population Aging, Healthcare Expenditure and Public Debt Sustainability in OECD and EU Countries: A Systematic Review
Purpose: This study undertakes a systematic review of the empirical and theoretical literature to examine how demographic ageing and associated expenditure categories—most notably healthcare spending and pensions—shape public debt sustainability across OECD and European Union countries. Design/Methodology/Approach: The study is grounded in a systematic literature review following the six-step framework proposed by Durach et al. The search covers the period from 2000 to 2025 using Scopus and Web of Science. A final sample of 18 high-quality studies was analysed using narrative thematic synthesis. Findings: The review reveals three interconnected transmission mechanisms: direct expenditure pressures through age-related spending, indirect effects via intergenerational redistribution, and political economy dynamics crowding out public investment. The relationship between ageing and fiscal sustainability exhibits substantial nonlinearity conditional on institutional quality. Practical Implications: Reconciling fiscal sustainability with adequate social protection in ageing economies requires coordinated structural reforms embedding demographic constraints within medium-term fiscal frameworks while preserving intergenerational equity. Originality/Value: This review contributes a novel integrated framework bridging fragmented evidence across debt sustainability analysis methodologies, econometric approaches, and overlapping generations models, identifying convergence and divergence in empirical findings.