CMI Working Paper 119 is issued alongside the updated version of the CMI Mortality Projections Model, CMI_2018. An updated version of Working Paper 119 was released in April 2019 to correct text on pages 26 and 37.

More recent versions of the CMI Mortality Projections Model have subsequently been released. A full list of the versions of the Model is available on the mortality projections page.

Important note: updated version of CMI_2018 software

An updated version of the CMI_2018 software, v02, was released in April 2019 to address an issue with the user interface that may lead to incorrect results.

The issue is that if a user:

  • opted to use the Advanced parameters and specified any non-zero value for the constant additions to mortality improvements by age, and
  • reselected the Core parameters,


  • the resulting projection used the values from the Advanced parameters, not the Core value of nil at all ages, and
  • the output from the Model in this scenario would state invalidly that it is from the Core version.

We have also corrected a separate issue that would have prevented the Model from running if the user chose to enable automatic adjustment of smoothing parameters for other populations.

Release of CMI_2018 v3 

We have released CMI_2018 v3, which makes a number of enhancements to the interface to the software since CMI_2018 v2, which do not affect the calculations. The key change, in response to requests from Subscribers, is to allow the initial addition to mortality improvements (“A”) to be used alongside Advanced parameters, rather than only as an Extended parameter, as in CMI_2018 v2.

We previously made CMI_2018 v3 available as a “beta” version. The updated version corrects the calculation of deviance and deviance residuals in cases where age/year cells in the calibration datasets have no deaths. This does not affect the Core dataset, and only has a marginal impact on the fitted model for other datasets that we have tested. We have also amended the formatting of smoothing parameters to show more decimal places.

The new features of CMI_2018 v3 are included in CMI_2019.

The software, and the updated user guide, which describes the various changes, can be obtained using the links. 

A Briefing note on CMI_2018 has also been issued and is publicly available alongside this paper. It provides an overview of the latest version of the Model and is aimed at those receiving advice based on the Model, such as pension scheme trustees and Non-Executive Directors of insurance companies.

The latest version of the Model is calibrated to England & Wales population mortality data up to 31 December 2018. The calibration dataset is constructed in a similar way to the CMI_2017 dataset, but estimates of populations at high ages now incorporate the method proposed in Working Paper 106.

Following a proposal published in Working Paper 114 and confirmed, following consultation, in Working Paper 116, the Core value of the period smoothing parameter, Sk, has been reduced from 7.5 in CMI_2016 and CMI_2017 to 7 in CMI_2018. A new Extended parameter, the “initial addition to mortality improvements”, has been added to the Model software. This allows users to adjust the age-period component of initial mortality improvements more easily to reflect their views on appropriate improvements for specific populations. 

Core Projections generated by CMI_2018 produce lower expectations of life than those produced by CMI_2017 (with other parameters held constant) for all ages for both males and females.

Working Paper 119 contains numerical results from CMI_2018 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. These are updated versions of the methods paper and user guide published alongside Working Paper 105 for CMI_2017. Two additional spreadsheets have been released to show the derivation of the CMI_2018 dataset for males and females. The adjustments to population estimates at high ages are carried out in a separate spreadsheet

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 the button to proceed is disabled preventing you from running the software than please let us know at


View the previous versions of the CMI Mortality Projections Model

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