The Continuous Mortality Investigation (CMI) Mortality Projections Committee (MPC) published annual updates to the CMI Mortality Projection Model. This blog summarises the latest version, CMI_2021. There is more detail in the CMI_2021 FAQs (open access) and Working Paper 160 (restricted to CMI Subscribers).
The CMI Model is used by UK pension schemes and insurance companies which need to make assumptions about future mortality rates. The CMI Model projects mortality improvements (i.e. annual reductions in mortality rates) by interpolating between current mortality improvements and assumed long-term improvement rates. The current mortality improvements are calibrated to historical data for the general population, but users are encouraged to consider adjusting the Model’s parameters so that it reflects the specific population that they are using it for. Users must also form their own view of long-term improvements.
Standardised mortality rates in England & Wales in 2021 were on average 5% lower than in 2020. However, both years had significantly higher mortality than before the coronavirus pandemic: mortality in 2021 was 8% higher than in 2019, and mortality in 2020 was 14% higher than in 2019.
While mortality experience in 2020 and 2021 will affect actuarial calculations, it is not likely to be indicative of the future path that mortality rates will follow. For this reason, the standard version of CMI_2021 places no weight on the data for 2020 or 2021 when projecting mortality rates. However, users can modify the Model to take account of data for 2020 and 2021, fully or partially, if they choose. This is consistent with the approach taken for the previous version of the CMI Model, CMI_2020, which places no weight on data for 2020.
Because we place no weight on data for 2020 or 2021, differences in results between CMI_2019, CMI_2020 and CMI_2021 are relatively modest. CMI_2021 produces cohort life expectancies at age 65 that are about two weeks lower (about 0.2% lower) for both males and females, than in CMI_2020.
We are minded to place full weight on data for 2022 in CMI_2022 if mortality in 2022 is not deemed to be exceptional. We are currently publishing weekly updates on mortality, and our latest mortality monitor shows that mortality for the first eight weeks of 2022 has been broadly similar to the corresponding periods in 2019 and 2020, before the pandemic.
We would normally expect to release the next version to the CMI Model, CMI_2022, in March 2023. However, we are conscious that the ONS may re-state historical population estimates in early 2023, as a result of the 2021 census in England & Wales. We may delay the release of CMI_2022 to take account of such revisions.
