Reassessing socioeconomic inequalities in mortality via distributional similarities

Commonly used measures of socioeconomic inequalities in mortality, such as the slope and the relative index of inequality, are based on summary measures of the group-specific age-at-death distributions (e.g. life expectancy). While this approach is informative, it ignores valuable information contained in the group-specific distributions. We apply and evaluate a novel measure of socio-economic inequality in mortality. Leveraging a metric of statistical distance, our Population Total Variation (PTV) measure is sensitive not only to changes in the means or variances, but also to broader mortality changes that affect distributional shapes. The PTV also allow the levels and trends of socioeconomic inequalities in mortality to be decomposed into mortality changes versus changes in the composition of the population. We use mortality data by socioeconomic groups to assess mortality inequalities with both established measures and our proposed PTV. Our findings suggest that levels and trends in mortality inequalities computed with the PTV differ compared to other conventional summary-based measures. The method we propose can be applied to any context where mortality rates are available by socio-economic groups. We conclude that measuring distributional similarities in mortality enhances our understanding of between groups inequalities in mortality.