David Spiegelhalter Quotes

We spent ages... working... for child heart surgery... such a delicate area, trying to find the wording for... random error or binomial variability... [Y]ou can give a percentage... 95% . Well, am I going to be one of the 5% or one of the 95%? We don't know. It's just chance or luck, fortune. We can't... use those words in... delicate situations... operating on children... Then we came up with a good phrase... which we used and tested on parents... It's "unforeseeable factors," not "unforeseen factors," because that would suggest someone's to blame... [T]he unforeseeable factors could lead some people to... not survive the operation, and some to survive. So... we can put you in a group, but we can't go beyond that... [O]nly what develops over time, in terms of complications, or something like that, could... put... you in one group or another. "Unforeseeable factors," I really like that phrase. I try to use it all the time, I recommend it.

One of the other things we do in the book is talk about radiation... [Y]ou can say exposure to radiation, you can talk in terms of micro-lives or cigarette equivalents. So... a flight to New York, the radiation you get from that is equivalent to smoking a couple of cigarettes, about 1/2 hour of your life... The whole body CT scan... exposing yourself... to possibly an unhealthy dose of radiation... 150 microlives, smoking about 300 cigarettes, about the same as standing about 1 1/2 miles from the Hiroshima explosion. ...[W]hen they advertise these things for a thousand quid, they don't tell you that.

I do math and statistics. That's what I do, so I come at the whole business of turning numbers into stories. ...How can we turn numbers into stories?

When it comes to trying to prevent you endangering other people, I don't see anything wrong with persuasion. ...[Y]ou shouldn't be... [endangering people] and you should be trying to be persuaded, if not forced... I get quite Stalinist on these things because... it's so irresponsible for some people to endanger the health of others. If they wanted to make their own decision that only affects them, it's very different, and I wouldn't want to persuade anyone...

Misleading anecdote is someone smokes 20 a day and lives to 110, [or] who buys some tablets off the web and their cancer goes away... These are not representative... stories... [T]his is an active area of research, and it's been shown that if you present information in the way that Michael was presenting, as icon arrays, show both the good and the bad, show the totality, [it's been] shown empirically that you can make people less influenced by misleading anecdotes.

When it comes to vaccines and infectious diseases, nobody is an individual... [With] [i]nfectious diseases... measles when it comes to vaccine decisions, or COVID-19 when it comes to taking precautions, we're not individuals. We are members of society, and there's no... "optimize your individual situation." You have... an absolute responsibility... to protect the people around you, particularly the vulnerable... [T]hat's why... people who avoid vaccinating their kids is outrageous and irresponsible... they are endangering weaker kids who might not be able to have the vaccines because their immune system is compromised or for some [other] reason... [S]imilarly, if young... healthy people... not... harmed by the virus, go around being irresponsible, they are endangering the lives of older people surrounding them, in particular, their own family.

This is called a hazard curve. ...This is the chance of dying before your next birthday, on average. ...[I]t's... on a , so 10%... (1 in 10) 83 year olds will not see 84... 1 in 100 people like me [age 59] will not see their next birthday. 1 in 1,000 thirty-two year olds, and 1 in 10,000 7 year olds... and there is a... lump, sadly jumping up at 17, as you can imagine... boys... a risk-taking lump, but if you ignore that lump... it's a... straight line between... 7 and 90.

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 ...

This current COVID-19 virus... is a classic situation... of... an uncertainty problem, rather than a risk problem because we... don't know the parameters. We don't know... how it might spread in Great Britain. We don't know the effectiveness of the interventions that are going to be made. So... when you're making projections... over the next 6 months, there's a massive range of possibilities, up to 1/2 million deaths... from about 5... the most optimistic... [A]ny quantification, giving any probabilities would be... very ambitious...

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

[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."

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...

When epidemiologists... do studies, when they follow lots of people for years, they measure the effects of various habits, in terms of s. This is what it does to your hazard every year. So if you have a daily sausage or a bacon sandwich, this goes up by about 10%, a fixed amount... as your... annual risk. 10% increase in your annual risk of death, of not making it to your next birthday.

Psychologists got hold of this lovely idea of why we're trying to do it. I don't care what people do, so I'm not trying to change what they do, particularly. ...It would be nice if they could remember it... get the gist of something... learn something, but I don't even care too much about that. Psychologists have got this great scheme of what, perhaps, we're really trying to do, which is trying to breed some immunity to misleading anecdote, which is... the fact that we're so influenced by idiotic stories we hear on the web, or from our friends and neighbors.

The point is... that you can make these comparisons quite easy... is... 8 [micromorts], running a marathon is... 7, ... 5, 's going to be 400...