Archive for Boris Johnson

the limits of R

Posted in Books, pictures, R, Statistics with tags , , , , , , , , , , , , on August 10, 2020 by xi'an

It has been repeated many times on many platforms, the R (or R⁰) number is not a great summary about the COVID-19 pandemic, see eg Rossman’s warning in The Conversation, but Nature chose to stress it one more time (in its 16 Jul edition). Or twice when considering a similar piece in Nature Physics. As Boris Johnson made it a central tool of his governmental communication policy. And some mayors started asking for their own local R numbers! It is obviously tempting to turn the messy and complex reality of this planetary crisis into a single number and even a single indicator R<1, but it is unhelpful and worse, from the epidemiology models being wrong (or at least oversimplifying) to the data being wrong (i.e., incomplete, biased and late), to the predictions being wrong (except for predicting the past). Nothing outrageous from the said Nature article, pointing out diverse degrees of uncertainty and variability and stressing the need to immediately address clusters rather than using the dummy R. As an aside, the repeated use of nowcasting instead of forecasting sounds like a perfect journalist fad, given that it does not seem to be based on a different model of infection or on a different statistical technique. (There is a nowcasting package in R, though!) And a wee bit later I have been pointed out at an extended discussion of an R estimation paper on Radford Neal’s blog.

politics coming [too close to] statistics [or the reverse]

Posted in Books, pictures, Statistics, University life with tags , , , , , , , , , , , on May 9, 2020 by xi'an

On 30 April, David Spiegelhalter wrote an opinion column in The Guardian, Coronavirus deaths: how does Britain compare with other countries?, where he pointed out the difficulty, even “for a bean-counting statistician to count deaths”, as the reported figures are undercounts, and stated that “many feel that excess deaths give a truer picture of the impact of an epidemic“. Which, on the side, I indeed believe is a more objective material, as also reported by INSEE and INED in France.

“…my cold, statistical approach is to wait until the end of the year, and the years after that, when we can count the excess deaths. Until then, this grim contest won’t produce any league tables we can rely on.” D. Spiegelhalter

My understanding of the tribune is that the quick accumulation of raw numbers, even for deaths, and their use in the comparison of procedures and countries is not helping in understanding the impacts of policies and actions-reactions from a week ago. Starting with the delays in reporting death certificates, as again illustrated by the ten day lag in the INSEE reports. And accounting for covariates such as population density, economic and health indicators. (The graph below for instance relies on deaths so far attributed to COVID-19 rather than on excess deaths, while these attributions depend on the country policy and its official statistics capacities.)

“Polite request to PM and others: please stop using my Guardian article to claim we cannot make any international comparisons yet. I refer only to detailed league tables—of course we should now use other countries to try and learn why our numbers are high.” D. Spiegelhalter

However, when on 6 May Boris Johnson used this Guardian article during prime minister’s questions in the UK Parliement, to defuse a question from the Labour leader, Keir Starmer, David Spiegelhalter reacted with the above tweet, which is indeed that even with poor and undercounted data the total number of cases is much worse than predicted by the earlier models and deadlier than in neighbouring countries. Anyway, three other fellow statisticians, Phil Brown, Jim Smith (Warwick), and Henry Wynn, also reacted to David’s tribune by complaining at the lack of statistical modelling behind it and the fatalistic message it carries, advocating for model based decision-making, which would be fine if the data was not so unreliable… or if the proposed models were equipped with uncertainty bumpers accounting for misspecification and erroneous data.

punch [him] back, Britain!

Posted in Statistics with tags , , , , , , , on December 12, 2019 by xi'an

total bullXit

Posted in pictures, Travel with tags , , , , , , , , , , , , , on October 31, 2019 by xi'an

“Of course there will be an attempt to try to obfuscate the effect of this Act, but it does – the capitulation act, or the surrender act or whatever you want to call it – it does, I’m sorry, but it greatly enfeebles, it greatly enfeebles this government’s ability to negotiate.”

“But what I will say is that the best way to honour the memory of Jo Cox and indeed the best way to bring this country together would be, I think, to get Brexit done.”

“There’s a terrible kind of collaboration as it were, going on between people who think they can block Brexit in Parliament and our European friends.”

“What will synthetic biology stand for – restoring our livers and our eyes with miracle regeneration of the tissues, like some fantastic hangover cure? Or will it bring terrifying limbless chickens to our tables?”

“I can hardly condemn Ukip as a bunch of boss-eyed, foam-flecked euro hysterics, when I have been sometimes not far short of boss-eyed, foam-flecked hysteria myself.”

“We will leave the EU on 31 October, deal or no deal. The way to get a good deal is to prepare for a no deal.”


Nature snippets

Posted in Statistics with tags , , , , , , , , , , , , , on October 1, 2019 by xi'an

In the August 1 issue of Nature I took with me to Japan, there were many entries of interest. The first pages included a tribune (“personal take on events”) by a professor of oceanography calling for a stop to the construction of the TMT telescope on the Mauna Kea mountain. While I am totally ignorant of the conditions of this construction and in particular of the possible ecological effects on a fragile altitude environment, the tribune is fairly confusing invoking mostly communitarian and religious, rather than scientific ones. And referring to Western science and Protestant missionaries as misrepresenting a principle of caution. While not seeing the contradiction in suggesting the move of the observatory to the Canary Islands, which were (also) invaded by Spanish settlers in the 13th century.

Among other news, Indonesia following regional tendencies to nationalise research by forcing foreign researchers to have their data vetted by the national research agency and to include Indonesian nationals in their projects. And, although this now sounds stale news, the worry about the buffoonesque Prime Minister of the UK. And of the eugenic tendencies of his cunning advisor… A longer article by Patrick Riley from Google on three problems with machine learning, from splitting the data inappropriately (biases in the data collection) to hidden variables (unsuspected confounders) to mistaking the objective (impact of the loss function used to learn the predictive function). (Were these warnings heeded in the following paper claiming that deep learning was better at predicting kidney failures?)  Another paper of personal interest was reporting a successful experiment in Guangzhou, China, infecting tiger mosquitoes with a bacteria to make the wild population sterile. While tiger mosquitoes have reached the Greater Paris area,  and are thus becoming a nuisance, releasing 5 million more mosquitoes per week in the wild may not sound like the desired solution but since the additional mosquitoes are overwhelmingly male, we would not feel the sting of this measure! The issue also contained a review paper on memory editing for clinical treatment of psychopathology, which is part of the 150 years of Nature anniversary collection, but that I did not read (or else I forgot!)