David Spiegelhalter Quotes

There is a way... which comes from economics and social science. It was developed by... Frank Knight, and Keynes used this... The distinction between risk and uncertainty...
[R]isk is about things... we... understand... known unknowns, to use Donald Rumsfeld's... great phrase... [something] we can put numbers on, things within... circumscribed situations... A lot of medicine is like this... repetition, a lot of data. ...[I]nsurance is like this ...We know roughly what the chances are, and we can talk about the numbers.
Uncertainty is when... we don't know the numbers, or... deeper... we don't even know... the problem... the options... the possible outcomes...

(DVTs) [normally] happen to around one person per 1,000 each year... out of 5 million people getting vaccinated, we would expect... 5,000 DVTs a year, or... 100 every week. So it is not at all surprising that there have been 30 reports.

We need to think slow instead of fast, and resist drawing causal links between events where none may exist.

This was discovered by Gompertz in 1825. There's something about our bodies, the way that we age, that means that every year our chance of dying increases by the same amount, 9%.

In the trials that led to the vaccines... adverse events were reported by 38% of those receiving the real vaccine... 28% of those who received the control [dummy, or fake vaccine, of which some were meningitis vaccine] also reported a side-effect. ...[F]ewer than 1% reported a serious adverse event, and of these... slightly more had received the dummy than the active vaccine. ...So there was no evidence of increased risk ...

If you go to the English Parachuting Association web site... you find this lovely Excel spreadsheet which has got all the deaths... [F]or the last 20 years, 4.6 million jumps, 48 deaths... or 10 in a million. On average, with going up in a plane... I thought there's around 7 or 10 in a million chances of me dying. There's 50 million people in England and Wales... Every day 50 of them have accidental or violent deaths... not to do with their health. So a couple are murdered a day, a few are run over, some people fall off ladders, etc... So that's 1 in a million... Our daily dose of acute risk is a [a 1 in a million chance of dying]. So jumping out of a plane is only about a week's worth. ...[I]n terms of overall mortality... at my age, 59, it's 7,000 micromorts a year in terms of my chances of dying. So an extra 7 or 10 on top of that... [I]t's worthwhile doing... it once....So I did it [parachuted], and I survived.

[W]e tend to think... of something that's going to happen... soon, or is well understood as risk, but if we're talking about what will happen in the world in ten years time. Who's going to start putting chances on this. You'd be... deluded... There's much... deeper uncertainty or... radical uncertainty...

[S]easonal flu—average year—kills 6,000 people in this country. Mainly old... vulnerable... frail...[etc.] So we are hit by this, year after year... epidemics... we've got to put this into perspective... [T]o an extent it is a trade-off between massive disruption... [I]f you say everyone has to stay in their home for 4 weeks... that's not just economic loss. It has a massive... health... [detriment] in terms of... mentality and fitness. Norsemen of harm will be done... so it's not just a matter of... "Minimize the number of deaths."

The most serious problem is anaphylactic reactions, and the advice is not to inject anyone with a previous history of allergic reactions to either a prior [vaccine] dose... or its ingredients.

[W]hen... there have been 30 "thromboembolic events" after around 5m vaccinations, the crucial question... is: how many would be expected anyway, in the normal run..?

Life-expectancy reduced by 1 year = about 30 minutes off your life expectancy for each day with the habit = 1

So we've been trying to think of another metaphor... and the one we caught hold of is... speed of aging. So it's turning these numbers, rather bold numbers quite difficult to understand, into stories, and the story we've got is, "Getting older quicker" or "Aging Slower"...

What we use in the book... are ways which we think might... provide gripping narratives, and yet provide a realistic way of communicating small risks...

So... in the book we make all these comparisons... That's acute timing risk, things that are going to kill you on the spot. ...What about the other sort of risks? ...You can have your spam ...[T]hat is not going to kill you on the spot. Well, it might. ...You might choke on...[it]... but it's... unlikely...

Framing is absolutely vital. ...All the work in communications is driven by the work of psychologists like Kahneman, Tversky...[etc.] The simplest one... is not always to talk about s, but to talk about s, and preferably... to give both. Our predict systems are almost always... positively framed, all in terms of survival. So we draw survival curves, not mortality curves... How long can you be without this condition. ...In a way you should give both, but ...it makes a big difference ...whether you talk about 2% mortality or 98% survival. ...2% mortality sounds rather terrifying while 98% survival sounds rather good, and we don't want to unnecessarily upset people... [W]e are all going to die ...It's 100% mortality in the end, but you want to show a decline in survival ...because it's just fairer and more likely to get people engaged rather than frighten them off immediately. ...[W]hen we ...provide an icon array that shows everybody, it shows the deaths ...patients like it. ...They like seeing out of 100 people ...in 10 years time, how many people are going to be alive ...because they have the chemotherapy now, or dead because of breast cancer...[etc.]