Future Life Expectancies in Ireland

Abstract

Mortality forecasts for the Irish population are published following each census by the Central Statistics Office (CSO) as part of their labour force and population projections. The projections rely on identifying and extrapolating past trends in mortality improvements. However, since the calendar year 2011, there has been a significant slow-down in mortality improvements and, in fact, mortality rates observed at ages above 90 years increased in Ireland - a reversal of the long-term trend decline that must cause much unease to public health policy-makers. The recent change in trend poses challenges when forecasting mortality rates. This paper sets out the approach eventually adopted by the CSO in the recent mortality projections, and contrasts it with other extrapolative methods including the increasingly popular stochastic and coherent methods. Comparing the outputs with these models gives a measure of the uncertainty of the future mortality forecasts for Ireland. The mortality projection for Ireland is also compared with the cohort-adjusted approach employed by the Office of National Statistics (UK) for mortality projections for Northern Ireland, Scotland, and England & Wales. We report that there are only minor differences in projected life expectancies, despite the differences in approaches and assumptions used, so we can conclude that the official mortality rates for Ireland (Central Statistics Office, Ireland (CSO, 2018)) and Northern Ireland (Office for National Statistics (ONS, 2017b)) are not inconsistent. Previous CSO mortality projections have been adopted by the actuarial profession in Ireland and others over the last decade for reserving for pension liabilities, for estimating the value of pensions, and to help judge the sustainability of the Social Insurance Fund. This detailed analysis of the CSO’s most recent projections, and comparison with other mortality projections for Ireland, will help those considering its adoption for their purposes and gives a measure of the uncertainty surrounding the forecast. We conclude by setting out the implied cohort life expectancy in Ireland, based on the CSO mortality projections, to help individuals’ planning for their future lifetime.