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Turning the tables

Traditional actuarial mortality analysis was done by expressing a portfolio's mortality experience relative to a reference mortality table (a so-called A/E analysis).  In modern actuarial work the A/E analysis is supplemented (or even replaced) with a multi-factor statistical model; besides age and gender, common risk factors include pension size, geodemographic profile and early-retirement status.
Written by: Stephen RichardsTags: Filter information matrix by tag: A/E, Filter information matrix by tag: standard table

Modelling improvements in experience data - I

In the first of a pair of blogs we will look at how to allow for changes in mortality levels when calibrating models to experience analysis.  We start with time-varying extensions of traditional parametric models proposed by actuaries, beginning of course with the Gompertz (1825) model:

\[{\rm Gompertz}: \mu_{x,y} = e^{\alpha+\beta x + \delta(y-2000)}\qquad (1)\]

Written by: Stephen RichardsTags: Filter information matrix by tag: mortality improvements

Modelling improvements in experience data - II

In my previous blog I looked at the implied mortality improvements from time-varying traditional actuarial survival models.  In this blog we consider the implied improvements under the newer Hermite-spline model I proposed in Richards (2019).  This paper included an explicit attempt to model age-related mortality changes, as dis

Written by: Stephen RichardsTags: Filter information matrix by tag: mortality improvements

Piquing interest in improvements

When underwriting a pension scheme for a bulk annuity or longevity swap, the first concern is understanding what mortality levels are, especially differentials amongst sub-groups. The next concern is whether the recent mortality improvements in the pension scheme are in line with the pricing basis; if the scheme has experienced faster improvements, say, then this would be a valuable insight for pricing.

Written by: Stephen RichardsTags: Filter information matrix by tag: mortality improvements, Filter information matrix by tag: portfolio-specific underwriting

Seasoned analysis

The importance of seasonal analysis was underscored by a recent letter form the UK insurance regulator. In a previous blog, I looked at quarterly seasonal variation in a portfolio of defined-benefit pensions, and in a more recent blog I looked at monthly seasonal variation in mortality in England & Wales.

Written by: Stephen RichardsTags: Filter information matrix by tag: season

The renewed importance of place

In my previous blog I showed how suddenly the excess deaths rose in Scotland and England & Wales due to the ongoing COVID-19 pandemic.  I plotted the excess weekly mortality in two separate graphs because the two countries had such a similar experience that a single figure would have looked muddled.
Written by: Stephen RichardsTags: Filter information matrix by tag: coronavirus, Filter information matrix by tag: mortality

A week is a long time in a pandemic

According to British Prime Minister Harold Wilson, "a week is a long time in politics". As with politics, so also with the ongoing COVID-19 pandemic.
Written by: Stephen RichardsTags: Filter information matrix by tag: coronavirus, Filter information matrix by tag: mortality

Significantly enhancing your models

In building a mortality model (or any other kind of risk model) it is usually best to build a single, over-arching model rather than split the data into sub-groups (an approach called stratification, the disadvantages of which are discussed in Macdonald et al (2018)).  One obvious reason is to reduce the total number of parameters: why fit two parameters for age when one will do?
Written by: Stephen RichardsTags: Filter information matrix by tag: enhancement, Filter information matrix by tag: concealment, Filter information matrix by tag: stratification

COVID-19 mortality and sex

I recently looked at the progression of Covid-19 mortality risk with age.  As with all-cause mortality, another risk factor for Covid-19 is biological sex.
Written by: Stephen RichardsTags: Filter information matrix by tag: coronavirus, Filter information matrix by tag: mortality

COVID-19 mortality and age

When faced with a pandemic disease, such as the ongoing Covid-19 crisis, a multi-layered approach is useful.
Written by: Stephen RichardsTags: Filter information matrix by tag: coronavirus, Filter information matrix by tag: mortality