The Continuous Mortality Investigation (CMI) has proposed structural changes to the CMI Mortality Projections Model, CMI_2024, set to be released in the second quarter of 2025.
If implemented, the updates would result in cohort life expectancies at age 65, increasing by approximately five weeks for males and decreasing by about one week for females compared with the current CMI_2023 model.
The first proposed change involves explicitly accounting for the impact of the pandemic on mortality.
In previous versions, the CMI excluded data from 2020 and 2021, treating them as outliers unlikely to reflect future trends. Instead, a smooth trend was fitted to other years.
This approach was initially effective, but with five years of data now available, the CMI suggested a revised method, with the proposed model incorporating an explicit mortality shock for 2020, with waning effect in subsequent years.
The second proposed change aims to improve the model’s ability to adapt to varying mortality trends across different age groups.
The current structure of the CMI_2023 model applied similar trend changes across all ages. However, recent data indicates that mortality trends have not followed a uniform pattern.
In 2024, mortality rates for individuals aged 75 to 100 were lower than in any previous year, while mortality rates for those aged 20 to 44 were significantly higher than before the pandemic.
Reforms on death certification implemented in September 2024 also influenced the data from that point onward. The CMI indicated that the cumulative standardised mortality rate for 2024 may be around 0.25% lower, and the reported mortality improvement may be about 0.25% higher than it would have been without the reforms.
The updated model would allow for separate trend adjustments across young, middle, and older age groups, aligning more closely with recent mortality patterns, the company said.
The CMI Model is widely used by pension schemes, insurers and reinsurers in the UK and internationally to inform assumptions about future mortality rates.
