The influence of selective mortality on poverty rates in later life: evidence from a Swedish cohort born in 1926.

Aims: Mortality influences the composition of the surviving population. Higher mortality among low-income individuals than high-income individuals may result in lower poverty rates in the surviving population. The objective of this study was to describe poverty rates for both survivors and deceased individuals in a cohort born in 1926.

Methods: We used Swedish total population data on the 1926 birth cohort (n = 83,382), calculating annual poverty rates from 1991 to 2016. We compared poverty rates for the entire cohort, those who died the next year, and those who survived for 5, 10, or 20+ years, measuring the impact of selective mortality as the differences in poverty rates between the cohort and these subgroups.

Results: Individuals who died the following year had higher poverty rates than the cohort at ages 65-90. Conversely, individuals who survived 5, 10, or 20+ years had lower poverty rates, with relatively small differences (1.1% to 6.9% lower) for survivors of 5 years or longer, and larger differences (26.4% to 32.8% lower) for those who survived 20+ years.

Conclusions: Despite differences in mortality rates by income, selective mortality had only a modest impact on poverty rates. If life expectancy rises for all, and a more diverse population reaches old age, our findings indicate a potential slight increase in poverty rates due to reduced mortality as a selective factor. These findings emphasise the need to consider mortality selection when addressing future poverty rates in older adults.