Determinants of life expectancy: evidence from World Bank income groups using a panel dummy interaction approach.

Purpose: Achieving optimal health outcomes is central to global health policies. This study examines the impact of out-of-pocket (OOP) health expenditures and other determinants on life expectancy across income groups classified by the World Bank.

Design/methodology/approach: Using panel data and a fixed-effects model with dummy interactions, the findings reveal that OOP expenditures reduce life expectancy more in low-income economies, underscoring the need to lower financial barriers to healthcare.

Findings: Gross domestic product (GDP) per capita is significant for improving life expectancy more in low-income economies, but diminishing returns suggest aligning growth with health policies. Immunization consistently improves life expectancy, highlighting preventive care's importance. Unemployment limits healthcare access, particularly in low-middle-income economies, requiring policies to address economic instability. Alcohol consumption adversely affects life expectancy in high-income economies, highlighting the impact of lifestyle changes and the need for regulatory interventions.

Practical implications: By exploring the interplay of health expenditures, socioeconomic factors and lifestyle risks, the study offers insights for equitable global health policies aimed at improving health outcomes across income groups.

Originality/value: (1) While previous studies have analysed the impact of various socio-economic factors on life expectancy in developed economies, little is known about the impact of these factors in Low and Middle Income Economies. (2) Moreover, the impact of out-of-pocket health expenditure on life expectancy has not been comprehensively analysed across different income groups. (3) Findings reveal that out-of-pocket expenditures negatively affect life expectancy more in low-income economies than in high-income economies, emphasizing the need for reducing the financial burden to improve healthcare access. (4) Alcohol consumption adversely impacts life expectancy in high-income economies, highlighting the need for regulatory interventions targeting lifestyle-related risks. (5) This study enhances understanding of how health expenditures, socio-economic factors, and lifestyle choices influence life expectancy across income groups, offering insights to guide equitable global health policies.