CMI Working Paper 177

CMI Working Paper 177 is issued alongside the updated version of the CMI Mortality Projections Model, CMI_2022.

A frequently asked questions (FAQ) page on CMI_2022 has also been issued and is publicly available alongside this paper. It provides a brief overview of mortality improvements and the latest version of the Model. 

The latest version of the Model is calibrated to England & Wales population mortality data up to 31 December 2022. The exceptional nature of mortality during the pandemic means that “business as usual” updates to the Model would have shown larger falls in projected mortality improvements and cohort life expectancy than most users of the Model would have considered reasonable. Because of this, we modified the calibration process for CMI_2020 so that users could choose to place more or less weight on data for individual years. We have retained this feature for CMI_2021 and CMI_2022. For the Core version of CMI_2022, we use a weight of 0% for 2020 data and 2021 data, a weight of 25% for 2022 data, and weights of 100% for other years.

We have revised the population estimates we made in the CMI_2022 dataset to reflect the results of the 2021 census. Our method means that:

• The CMI_2022 exposures for 2021 match the ONS population estimates exactly for single years of age up to 84 and for the combined 85+ age group. The split of population at ages 85 and above reflect our use of the Kannisto-Thatcher method in CMI_2021.
• Population estimates differ between CMI_2021 and CMI_2022 for 2012 to 2020. The difference between the ONS estimate and the CMI_2021 dataset in 2021 is assumed to decrease linearly, by cohort, to nil in 2011.
• The CMI_2022 exposures match the CMI_2021 exposures for 2011 and earlier. 

Core projections generated by CMI_2022 produce lower cohort life expectancies than those produced by CMI_2021 (with other parameters held constant) for most ages. 

Working Paper 177 contains numerical results from CMI_2022 and commentary. It also contains analysis of recent mortality in the general population and illustrations of the sensitivity of the Model to new data.

The Model is accompanied by a methods paper, containing technical details of the calculations, and a user guide, describing how to use the software. Three additional spreadsheets have been released:

• Two spreadsheets show the derivation of the CMI_2022 dataset for males and females. 
• A spreadsheet that includes the values used in the charts in the results working paper. 

The software has been tested and found to work properly using Excel 2010 and Excel 2016 in a Windows environment. If you see a yellow banner in Excel with buttons saying e.g. ‘Enable Editing’ or ‘Enable Content’ then you will need to click on these buttons in order to run the software. If however, you see a red banner and you are unable to solve the issue following Microsoft's advice under the "Learn more" button, then please let us know at projections@cmilimited.co.uk.

The Mortality Projections Committee hosted a meeting on 19 July 2023, in conjunction with the Staple Inn Actuarial Society (SIAS), discussing the outlook for future mortality improvements. The presentation slides can be accessed here. 

Documents

• CMI Working Paper 177
• Frequently asked questions (FAQs)
• CMI_2022 methods
• CMI_2022 software user guide
• The updated Model, CMI_2022
• Spreadsheet of values used in the chart in Working Paper 177
• Derivation of the CMI_2022 male dataset
• Derivation of the CMI_2022 female dataset

Note: The previous versions of the CMI Mortality Projections Model can all be accessed on the mortality projections page.