Canaries in the Mine: A Second Update
by Rudolph Kalveks For several weeks now, I have been tracking the fate of the “Canaries in the Mine” to see what the Coronavirus death statistics (courtesy of Worldometer) can tell us about the progress of the epidemic in the UK, along with a selection of other countries. The method used is to fit the evolving historic death statistics to a simple Susceptible Infected Recovered/Resolved (“SIR” ) epidemiological model, as explained in the first article in this series. This data fitting exercise identifies four essential parameters that govern an archetypal epidemic in a given country or region. These correspond to the early rate of spread of infections, the rate at which infected individuals recover (or expire), the size of the (fatally) susceptible sub-population, and the date at which the epidemic starts. Historic death statistics are augmented daily, and so we should not generally expect the parameters obtained from such a data fitting exercise to remain constant over time. The circumstances where the parameters do remain stable are those where the new death statistics match those extrapolated from the historic statistics under the simple model. This requires (i) that an epidemic conform to a simple SIR profile, (ii) that there is no material change in the combined effects of the many surrounding factors that influence the parameters of the SIR model ...
