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Another look at the Gompertz model

The year 1825 was a significant one not only for actuaries but for the wider scientific community: Benjamin Gompertz published his landmark paper on the graduation of human mortality (Gompertz, 1825). There were at least three completely new ideas in his paper. First, he gave his famous law of mortality. To quote Gompertz:

Written by: Iain CurrieTags: Gompertz

Separation as a service

During the current Covid-19 pandemic, and in common with many service providers, we're dealing with support requests from users working at home. This isn't a huge upheaval for us, since we've always been a SaaS provider, and SaaS is intrinsically decentralised.
Written by: Gavin RitchieTags: technology, coronavirus, public health

Wash your hands, live longer

As the coronavirus circles the globe, the only thing spreading faster is disinformation on so-called "social media".  In addition to ridiculous conspiracy theories, quack preventions range from the ineffective to the downright dangerous.
Written by: Stephen RichardsTags: coronavirus, influenza, hygiene

Best practice in mortality work - regulatory comments

In a letter to the Chief Actuaries of UK insurance businesses, Malik (2019) highlighted two aspects of what the regulator regards as good practice in mortality work
Written by: Stephen RichardsTags: season, mortality improvements, cohort effect

Mortality crossover

In a previous blog I discussed the importance of mortality convergence to actuaries, i.e. how mortality differentials narrow with age and how this interacts with discounting of cashflows.
Written by: Stephen RichardsTags: mortality convergence, crossover

The sound of progress

A while back we discussed the important role existing licensed medications could play when applied to the diseases of aging. A comparable discussion can be had about existing non-drug interventions and treatments, such as, in this case the venerable ultrasound.
Written by: Gavin RitchieTags: longevity, ultrasound

Model selection

When fitting a mortality model, analysts are faced with the decision of which risk factors to include or exclude.  One way of doing this is to look for the improvement in an information criterion that balances the fit against the number of parameters.  The bigger the improvement in the information criterion, the more strongly the model with the smaller value is preferred.

Written by: Stephen RichardsTags: information criterion, AIC, relative likelihood

Constraints and the R language

This is the fourth and final blog on the use of constraints in the modelling and forecasting of mortality. The previous three blogs (here, here and here) demonstrated that there is no need to worry about which linear constraints to use: the fitted values of mortality and crucially their forecast values always come out the same.

Written by: Iain CurrieTags: identifiability constraints, R language

From magical thinking to statistical thinking

The Institute and Faculty of Actuaries in the UK has recently added mortality projection to its syllabus, so this year I have been teaching the subject for the first time to students at Heriot-Watt University.
Written by: Angus MacdonaldTags: mortality projections, deterministic models

Matrix repair

When fitting a statistical model we want two things as a minimum:

Written by: Stephen RichardsTags: information matrix, covariance matrix