CMI Working paper 63

Working paper 63: The CMI Mortality Projections Model, CMI_2012

Note: The latest version of the model, 'CMI_2015', is now available here

Working paper 63 accompanies the updated version of the CMI Mortality Projections Model, CMI_2012, and is issued alongside the model and an updated user guide.

The structure of the CMI_2012 model is identical to that of the previous versions; however, the default parameters contained in the model have been updated to reflect the latest England and Wales population mortality dataset. On this occasion there are two elements to updating the dataset:

  • The first element is to incorporate a set of revised population estimates for England and Wales for mid-2002 to mid-2010. The revised estimates were released by the ONS following the 2011 Census and provide a consistent time-series of population estimates to mid-2011.
  • The second element is to extend the dataset to include population mortality rates for 2011.

This working paper illustrates the impact of both these elements.

The default Initial Rates of Mortality Improvement are significantly lower than those published in CMI_2011 at the oldest ages, particularly for males. In contrast, at the youngest ages the default rates are higher than those published in CMI_2011, for both males and females. The comparison is more complex between ages 40 and 85 with estimates higher at some ages and lower at others. The revised population estimates have led to some quite significant shape changes by age, particularly for males where we have seen the near-removal of the peak and trough previously apparent in the dataset around ages 85 to 90. Core projections generated by the CMI_2012 model produce expectations of life which are generally lower than those produced by CMI_2011 (with other parameters held constant). At most ages the reductions are small (less than 1%). However, there are more significant reductions for males at ages 80+, driven by the revisions to population estimates.

A modified version of CMI_2011 (incorporating the revised population estimates referred to above) was produced to help the CMI Mortality Projections Committee understand the progression of the CMI Mortality Projections Model, from CMI_2011 to CMI_2012. The modified version of CMI_2011 is available on request to The CMI does not endorse its use for any particular purpose nor does it accept any liability for its use.





The previous versions of the CMI Mortality Projections Model can be accessed as follows:

  • CMI_2011 and its user guide can be accessed alongside Working paper 55.
  • CMI_2010 and its user guide can be accessed alongside Working paper 49.
  • CMI_2009, its user guide and an Excel spreadsheet containing additional results for the parameter sensitivity tests, as described in the user guide, can be accessed alongside Working paper 41.