More or Less

Tim Harford investigates some of the numbers in the news. On the programme:
Last week, Annunziata Rees-Mogg took to X to post a claim about the proportion of sex offences in Dorset that are committed by asylum seekers, writing that “asylum seekers make up 0.8% of Dorset’s population and 44% of alleged sex offenses. So unbelievable I had to check.” We checked too, and the number isn’t right.
In the last series of More or Less we suggested that nuclear power plant Hinkley C was spending so much on protecting the fish population that it would cost something like £250,000 per fish saved. We’ve had to take a look at that one too.
Last year, we looked at a report by the Bible Society based on polling from YouGov. The Quiet Revival suggested that churchgoing was on the rise in the UK, with young men leading the trend. YouGov now have an update on that survey.
How many caterpillars does a blue tit chick eat before it leaves the nest? In a recent nature documentary, Sir David Attenborough said the right number was 20,000. We’re not so sure.
If you’ve seen a number in the news you think we should take a look at, email the more or Less team: [email protected]
CONTRIBUTORS:
Madeleine Sumption, Director of the Migration Observatory at Oxford University
Professor David Voas, Emeritus Professor of Social Science in the UCL Social Research Institute
Annette Jäckle, Professor of Survey Methodology at the University of Essex and a Deputy Director of the UK Household Longitudinal Study
Dr Malcolm Burgess, Principal Conservation Scientist at the RSPB
CREDITS
Presenter: Tim Harford
Reporter: Lizzy McNeill
Producer: Nathan Gower and Josh McGinn
Series producer: Tom Colls
Production co-ordinator: Brenda Brown
Sound mix: James Beard
Editor: Richard Vadon

It’s said that AI could soon be coming for the jobs of artists, lawyers, and software engineers. But it might now also be threatening a role at the height of academia – are pure mathematicians safe?

Last month, a Stanford mathematician woke up to an email, claiming to have the solution to a problem he'd been working on for seven years - a 60-year-old conundrum known as "Erdos Problem 1196".

The answer had been generated in just 80 minutes - by ChatGPT.

Since the end of last year, AI has been providing solutions to a number of novel maths problems, but Problem 1196 is the first to raise eyebrows within the mathematical community.

In this episode, we talk to the mathematicians who've worked on Problem 1196 and find out what the rise of AI could mean for the future of their field.


CONTRIBUTORS:
Katie Steckles, Mathematician and communicator
Jared Duker Lichtman, Szegő Assistant Professor of Mathematics at Stanford University
Liam Price, amateur mathematician

Credits:
Presenter: Charlotte McDonald
Producer: Josh McMinn
Series producer: Tom Colls
Production co-ordinator: Brenda Brown
Sound mix: Dave O'Neill
Editor: Richard Vadon

According to the World Health organisation, smoking kills some 7 million people every year. It is one of the world’s leading causes of preventable death.
Because smoking causes lung cancer and other awful health conditions, many smokers switch to vaping - using nicotine-based e-cigarettes.
But the World Health organisation is also concerned about vaping. Last year they said 100 million people around the world are now using e-cigarettes, including millions of children, and warned that they were fuelling a new wave of nicotine addiction.
But how do the health risks of these two means of getting nicotine into your bloodstream compare?
According to a recent headline in the Daily Mail, they’re basically the same. Here’s the headline:
“Vaping is linked to lung and mouth cancer in major study, as experts warn: 'It is NOT safer than smoking’”
But is vaping really just as bad for you as smoking?
CONTRIBUTOR:
Professor Lion Shahab, Co-Director of the UCL Tobacco and Alcohol Research Group
CREDITS:
Presenter: Charlotte McDonald
Reporter/producer: Tom Colls
Production co-ordinator: Brenda Brown
Sound mix: Dave O’Neil
Editor: Richard Vadon

If you spend much time on social media, and we don’t necessarily recommend it, then you’ve probably come across a strange fascination with water consumption.
Mainly, this is people telling you that using AI is terrible for the planet because of how much water it uses. We’ve already made a couple of programmes about the numbers in those arguments and, long story short, they probably aren’t saying what you think they’re saying.
But on platforms like X, BlueSky, and TikTok, an opportunity to keep an argument going is rarely missed

And one of the numbers that’s been enlisted in that glorious cause concerns the water that’s used for a seemingly unrelated past-time - eating beef. Here’s an example from a user on X:
“A kilogram of beef requires over 15,000 litres of water to produce,” they wrote. “A vegan who uses ChatGPT every day is living a more sustainable lifestyle than someone who regularly eats beef while boycotting AI.”
Ignoring the AI part, is that true? Does it actually take 15,000 litres of water to produce a kilogram of beef?

It turns out that the number isn’t wrong, but it probably isn’t saying what you think it’s saying.
If you’ve seen a number you think we should take a look at, email the More or Less team: [email protected]
CONTRIBUTORS:
Mesfin Mekonnen, Assistant Professor at the University of Alabama
Mark Mulligan, Professor of Physical and Environmental Geography at King's College London
Tim Hess, Professor of Water and Food Systems at Cranfield University

CREDITS:
Presenter: Charlotte McDonald
Producer: Mhairi MacKenzie
Series producer: Tom Colls
Production co-ordinator: Brenda Brown
Sound mix: Emma Harth
Editor: Richard Vadon

Vaccine policy in the US is something of an ideological battleground.
Health Secretary Robert F Kennedy Jr is a vaccine sceptic, and since taking office he has attempted to remake US vaccine policy.
In March a judge blocked his proposal to cut the number of jabs that are recommended for kids.
At the same time, last year saw the worst measles outbreak in the US in decades. There were more than 2000 cases last year, and three people died. There have been more than 1500 cases so far in 2026.
There’s a lot going on, so it’s possible the public’s views on vaccination are shifting.
A new poll published by online news site Politico added a big claim into the mix. According to the headline “more Americans doubt vaccine safety than trust it”.
But is that what the survey actually found?
Dr David Higgins, a paediatrician and public health assistant professor who writes a Substack called Community Immunity, explains why he believes the headline is misleading.
If you've seen a number in the news you think we should take a look at, email [email protected]
Presenter: Charlotte McDonald
Series producer: Tom Colls
Production co-ordinator: Brenda Brown
Sound mix: Neil Churchill Editor:
Richard Vadon