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A Piecewise Linear Cohort Extension to the Cairns-Blake-Dowd Model

Sweeting, Paul and Zhao, Yiwei (2016) A Piecewise Linear Cohort Extension to the Cairns-Blake-Dowd Model. Discussion paper. Pensions Institute, Kent, UK (KAR id:58408)

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Age-Period-Cohort (“APC”) models have been criticised on a number of grounds. One area of concern is in relation to projecting future cohorts. However, we would argue that such projection is unnecessary in some key cases, such as for closed defined benefit pension schemes.

More fundamental issues relate to the fit itself. APC models typically use at least one parameter for each cohort, in addition to those used for parameters age and period. This leads to a large number of parameters which are not necessarily independent.

However, the model we propose here uses a potentially far smaller number of parameters that essentially describe times where a new type of cohort emerges. This is similar to the trend-change models of mortality improvement discussed by as described by Sweeting (2011), Coelho and Nunes (2011), and van Berkum et al (2014). Because this cohort approach identifies a small number of changes in cohort rather than imposing a new cohort parameter for each year of birth, this reduces the risk of interdependence.

Item Type: Monograph (Discussion paper)
Uncontrolled keywords: Mortality modelling
Subjects: Q Science > QA Mathematics (inc Computing science) > QA273 Probabilities
Q Science > QA Mathematics (inc Computing science) > QA276 Mathematical statistics
Q Science > QA Mathematics (inc Computing science) > QA297 Numerical analysis
Divisions: Divisions > Division of Computing, Engineering and Mathematical Sciences > School of Mathematics, Statistics and Actuarial Science
Depositing User: Paul Sweeting
Date Deposited: 04 Nov 2016 17:28 UTC
Last Modified: 08 Dec 2022 23:00 UTC
Resource URI: (The current URI for this page, for reference purposes)
Sweeting, Paul:
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