Working Paper 166: Fitting UK and US mortality projection models to each other’s data

Working Paper 166 compares two mortality projection models – the latest version of the CMI Mortality Projections Model, CMI_2021, and the latest Mortality Improvement Scale, MP-2021, produced by the Society of Actuaries (SoA) Retirement Plans Experience Committee (RPEC). We applied both models to data for England & Wales and the US and compared results.

The two models have similar principles – both project mortality improvements by interpolating between recent mortality improvements, estimated based on historical data, and assumed long-term rates of mortality improvement. However, the details of the models differ, including how they estimate current mortality improvements and the period over which mortality improvements converge to the long-term rate. 

Our analysis focusses on comparing how results for a given country vary between the two models, rather than how results vary between the countries. We find that for both datasets and most ages:

  • MP--2021 leads to higher cohort life expectancies than CMI_2021.
  • Life expectancy is more sensitive to the long-term rate for MP-2021 than for CMI_2021.

Events calendar

No results found.