## COVID by numbers [not a book review]

Posted in Books, Kids, Statistics with tags , , , , , , , , , on October 13, 2021 by xi'an

David Spiegelhalter and Anthony Masters have made a book out of their COVID related columns in The Observer. Here are ten key figures extracted from that book:

1. The UK was hit by more than 1,000 separate outbreaks (…) [with] far more imports of Sars-CoV-2 from France, Italy and Spain than from China
2. Reported Covid deaths depend on the day of the week (due to delayed reporting, and a weekend effect, but smoothing is very rarely applied)
3. In the first year of Covid, over-90s had 35,000 times the risk of dying of Covid-19 as young children (with no relevance of the figure per se since an extra death of a young child would have moved it from 35,000 to 32,000, since there were thankfully so few deaths of young children)
4. 2020 saw the highest number of deaths since 1918 in England and Wales (even when correcting for population increase or population ageing)
5. The UK has led the World in testing Covid treatments (like dexamethasone and hydroxychloroquine, thanks to the centralised NHS, making me wonder why France with another centralised and public health structure was not able to do the same)
6. People who have died with Covid have on average lost about 10 years of life (contrary to the authors’ intial hunch, and mine as well, to oppose to the less relevant loss of life expectancy across the entire population)
7. Most people died “of” Covid rather than “with” it, but most have also had other medical conditions (with 91% of pre-COVID conditions)
8. Alcohol consumption stayed the same during lockdown (which came as a surprise, given the general feeling for the opposite, and still as a worrying indicator of alcoholism)
9. Most people with Sars-CoV-2 don’t infect anyone (which would need more details, as the figure should be weighted by the base probability to infect someone)
10. The pandemic has been a net lifesaver for young people (with 300 fewer deaths for 15-29 year old, but it also has had a potentially negative impact on their life expectancy).

## postdoc on COVID-19 modelling in Lugano

Posted in pictures, Statistics, Travel, University life with tags , , , , , , on July 24, 2021 by xi'an

A new call for postdoctoral applications from my friend Anto: a postdoctoral position is opening this Fall at the Università della Svizzera italiana (USI) in Lugano, Switzerland, under her direction, for conducting interdisciplinary approach to modelling the consequences of the COVID-19 pandemic and responses to it on other outcomes, such as mortality.

## Medellin

Posted in Kids, pictures, Travel with tags , , , , , , , on June 15, 2021 by xi'an

My nephew Paul and a fellow student made this nice mute video as a final project of his cinema degree in Rennes:

## COVID-19, the musical

Posted in Kids, Statistics, University life with tags , , , , , , , on May 16, 2021 by xi'an

## hands-on probability 101

Posted in Books, Kids, pictures, Statistics, University life with tags , , , , , , , , , on April 3, 2021 by xi'an

When solving a rather simple probability question on X validated, namely the joint uniformity of the pair

$(X,Y)=(A-B+\mathbb I_{A

when A,B,C are iid U(0,1), I chose a rather pedestrian way and derived the joint distribution of (A-B,C-B), which turns to be made of 8 components over the (-1,1)² domain. And to conclude at the uniformity of the above, I added a hand-made picture to explain why the coverage by (X,Y) of any (red) square within (0,1)² was uniform by virtue of the symmetry between the coverage by (A-B,C-B) of four copies of the (red) square, using color tabs that were sitting on my desk..! It did not seem to convince the originator of the question, who kept answering with more questions—or worse an ever-changing question, reproduced in real time on math.stackexchange!, revealing there that said originator was tutoring an undergrad student!—but this was a light moment in a dreary final day before a new lockdown.