Impact of personal income on mortality by age: biological versus socio-economic effects

TL;DR

This study investigates how personal income influences mortality across different age groups in France, the US, and South Korea, finding that income has limited impact on infant and elderly mortality, suggesting biological factors dominate at these ages.

Contribution

It provides comparative analysis across three countries showing weak income-mortality correlation at age extremes, challenging common assumptions about socio-economic effects on mortality.

Findings

Weak correlation between income and infant mortality

Income has limited influence on mortality in the elderly

Biological factors likely dominate at age extremes

Abstract

The influence of per capita income on life expectancy is well documented, mostly through studies of multinational samples. However, one expects fairly weak correlations at both ends of the life span, that is to say in early infancy and in age groups of elderly from 85 to 100 years. The reason is that at both ends mortality is largely controled by biological factors rather than by socio-economic conditions. In order to test this conjecture, we explore the influence of income on age groups, separately in France, the United States and South Korea. More precisely in each country we compare income and mortality data in as many regional subunits as possible. One noteworthy constatation is that, contrary to a common view, personal income is only weakly correlated with infant mortality (i.e. mortality under the age of one year). More broadly, we propose as a conjecture that the common pattern revealed by the analysis of the three countries is also valid in other developed countries.