Information Matrix
Filter Information matrix
Posts feedSignificantly 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?
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.
COVID-19 mortality and age
When faced with a pandemic disease, such as the ongoing Covid-19 crisis, a multi-layered approach is useful.
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:
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.
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.
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
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.
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.
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.