Calibrating the CMI Model for Ireland

The Demography Committee of the Society of Actuaries in Ireland (SAI) has co-written a paper with the Continuous Mortality Investigation (CMI) of the Institute and Faculty of Actuaries (IFoA). Working paper 141 explores ways of adapting the CMI Mortality Projection Model for Irish population data, areas to consider when doing so and the likely challenges of such work. The paper also considers the potential impact on life expectancy of adapting the Model to use Irish population data.

The paper considers two approaches:

  • a full recalibration of the Model using Irish data and associated changes to the smoothing parameters; and
  • a simpler approach, using the initial addition to mortality improvements to broadly reflect historical differences in mortality improvements between Ireland and England & Wales.

Working Paper 141 shows how the Model could be adapted for Irish population data, reflecting higher mortality improvements in Ireland than in England & Wales in recent years. The analysis presented demonstrates the importance of adjusting the Core Model when using it for Ireland. Tailoring mortality improvements to Irish lives increases life expectancy for male pensioners by up to 5% compared to the Core Model.

While the paper is primarily aimed at actuaries considering the Model for Irish lives, it may also be of interest to actuaries considering the application of the Model to other populations or particular subgroups.