Tags
BBC Evening Extra, BBC GMU, BBC Northern Ireland Education Correspondent, BBC Talkback, Belfast Live, Guerra et al 2017, Jing Blakely and Smith 2011, Justin McCampbell, Michael McBride, NASUWT, Northern Ireland Assembly, Northern Ireland Education Minister, Professor Ian Young, Robin Swann, SPI-M, Stephen Elliott, The Belfast Newsletter, The Belfast Telegraph, The Daily Mirror, The Failure of R0, The Irish News, The Royal Statistical Society, The Scientific Pandemic Influenza Group on Modelling
The use of the R number in the Assembly’s release-of-evidence points to a profound misunderstanding of the limitations of that number. In particular, R is not an additive variable; one cannot meaningfully add the contribution to R of hair salons to the contribution to R of pubs and then compare with 1. This strategy makes no arithmetic sense.
Unfortunately, the R number changes with the model used to measure it. The Scientific Pandemic Influenza group on Modelling is a standing group that advises government on preparations to manage the risk of pandemics and keeps emerging evidence and research under review. SPI-M use approximately ten different models to arrive at an R number for the UK. This R number is calculated by attempting to somehow reconcile these differing values, each calculated with great uncertainty.
How can our MLAs possibly justify basing decisions which impact on people’s livelihoods, on the tiny R-related percentages published in the Assembly’s evidence? The uncertainty of R renders this unjustifiable.
These concerns about R are clear in the literature. Guerra et al. (2017) could only locate the R number for measles somewhere between 3.7 and 203.3.
Jing, Blakely and Smith (2011) published a paper entitled The Failure of R0, in which the authors conclude, “Rarely has an idea so erroneous enjoyed such popular appeal”.
Coming right up to date, The Royal Society’s report entitled Reproduction number (R) and growth rate (r) of the COVID -19 epidemic in the UK (on page 53) struggles to make the case for R: “Given the suggested wide bounds of uncertainty that surround estimates of R in particular … are they still of value in policy formulation? The answer is definitely, yes … this is certainly a much better place to be in than just making a guess through verbal argument.”
Northern Ireland’s Health Minister and his two shields, the Chief Medical Officer and the Chief Scientific Advisor attempt to see off detractors by urging them to look at the “evidence in the round.” I am confident that no amount of additional evidence produced by the Minister and his two advisors will see off the criticisms set out in this letter.