Information Matrix

In criminal investigation, it is well known that passing time obscures the facts, making what happened more difficult to discern. Eventually, the case turns cold - unlikely to be solved unless we discover new evidence. In some ways for over a century, epidemiologists have been dealing with just such a cold case, picking through the rubble of the 1918 Influenza pandemic and trying to make sense of what they find. But as we will see, debate continues in a number of areas.

Humanity has suffered from many pandemics in the past, but the SARS-Cov-2 virus is the first to have its genome studied so extensively while the pandemic is ongoing.  In a previous blog I looked at how the Delta variant displaced all other variants in the UK due to its increased infectiousness.  Unfortunately, the increased infectiousness of Delta was not accompan

This blog discusses misinformation - including deliberate disinformation - during the SARS-COV-2 pandemic. I won't link directly to anti-vaccine content to avoid adding search-engine credibility to material best left unfound.

The UK Health Security Agency recently issued a press release, warning that too few children were vaccinated against measles.  With the benefits of vaccination and a developed healthcare system, it is easy to forget that measles was often a fatal disease for young children.  Table 1 shows just how deadly measles was at the start of last century without vaccination:

Everyone is familiar with the idea of a forecast. You have data on a phenomenon up to the current time, and want to forecast the phenomenon at some point in the future.  The most obvious example is the weather forecast, but forecasting is also required in pension and annuity work.  For example, when calculating reserves for pension payments, some kind of projection is required for future mortality improvements.

The title of this blog is the opening of A Visit from St.

A spline is a mathematical function.  They are used wherever flexibility and smoothness are required, from computer-aided design and cartoon graphics, to the graduation of mortality tables (McCutcheon, 1974).  There are numerous different types of spline, but the most common is the spline proposed by Schoenberg (1964).  Figure 1 shows Schoenberg splines of degrees 0–3, all of which start in 2015: