More or Less

To find out where a virus comes from, researchers compare it to other viruses to try to trace its origin. This leads to claims like SARS-CoV-2 is 91 or even 96% similar to other known viruses. But what does that really mean? Tim Harford talks to the virus ecologist Marilyn J Roossinck.

The official number of deaths attributed to Covid 19 around the world in the whole of 2020 is 1.88 million. The global toll this year surpassed this figure on 11th of June. We look at how things are worse worldwide, despite vaccines and lock downs. Does the UK have the worst bathing sites in Europe? That’s certainly a claim made by a number of newspapers. We show why this is not the case. Health S...

Steven Johnson, author of Extra Life, tells the fascinating history of life expectancy, and the extraordinary achievements of the last century, in which it has practically doubled. It’s a story that has data at its heart, from the ground-breaking invention of the category itself in 17th century London to the pioneering social health surveys of W.E.B. Du Bois in 1890s Philadelphia. Tim Harford spok...

Covid cases are rising again in the UK – should we be worried about a third wave? Tim Harford speaks to David Spiegelhalter, Winton Professor of Risk at the University of Cambridge. How safe are smart motorways? Many listeners have concerns that they seem more dangerous than conventional motorways. We take a look at the numbers. What proportion of adults in England have been vaccinated? Listeners...

Health Minister Matt Hancock recently told the House of Commons that: “The number of vaccinations happening in Bolton right now is phenomenal - tens of thousands every single day.” We explain why this is not the case. The recent SNP election success has turned attention to the question of independence. We compare Scotland’s finances to the comparably sized Yorkshire and Humber region. How do you w...

Popular Netflix documentary Seaspiracy has sparked a lot of debate recently, including some controversy over some of the claims the documentary makes and the numbers behind them. One of the most striking is that: “if current fishing trends continue we will see virtually empty oceans by the year 2048.” Although overfishing is a global problem, we take a look and find that this scenario is unlikely.

Wales has given one vaccination dose against Covid 19 to a larger proportion of their population than any other country except a couple of super tiny ones. They’ve given one vaccine dose to over 80% of their adult population. We explore some reasons why they seem to be doing so well. The UK continues to do poorly at Eurovision – we take a look back over the years to examine why the UK used to do w...

The Recovery Trial, a nation-wide clinical study in the UK, helped identify treatments for Covid 19 in the early months of the pandemic. Tim Harford speaks to Professor Martin Landray of Oxford University whose team established the randomised trial.

Tim Harford interviews Milo Beckman - a young mathematician, still in his twenties, who has written a book called ‘Math without Numbers’. Milo explains why he wanted to strip out digits to make it easier to describe the beauty of mathematics.

Mexico City’s official Covid 19 death toll did not seem to reflect the full extent of the crisis that hit the country in the spring of 2020 - this is according to Laurianne Despeghel and Mario Romero. These two ordinary citizens used publicly available data to show that excess deaths during the crisis - that’s the total number of extra deaths compared to previous years - was four times higher than...

Bayes’ Rule has been used in AI, genetic studies, translating foreign languages and even cracking the Enigma Code in the Second World War. We find out about Thomas Bayes - the 18th century English statistician and clergyman whose work was largely forgotten until the 20th century.

In 2020 there were 1.8 million reported Covid deaths. So far this year, we’ve had 1.2 million. We’re currently seeing around 12,000 deaths a day across the world. But while some areas are seeing falls in numbers, others such as India are seeing a surge. This week Tim Harford tries to answer the question: Will there be more global deaths this year from Covid 19 compared to last year?

If we brought together all the Covid 19 vaccine needed for the whole world, how much space would it fill up? An Olympic size swimming pool? We do some back of the envelope sums. Plus - we look at the increased risk of clots from pregnancy. Last week we looked at the increased risk of getting a clot from taking the combined contraceptive pill and compared it to risk of possible rare clots identifie...

The Astra Zeneca Covid 19 jab remains in the headlines because some regulators have concluded that it may raise the risk of a very rare type of blood clot, albeit to a risk that is still very low. In the past few weeks a number of countries have said they will limit its use to older age groups. But people are drawing comparisons to the contraceptive pill which is well-known to increase the risk of...

The impressive speed records of a well-known gamer called Dream for the video game Minecraft have come under scrutiny. Many say that Dream has completed speed runs in such a fast time that it doesn’t seem possible. Are these suspicions correct? We speak to stand-up mathematician Matt Parker who has looked at the probabilities on the elements of chance in the game to see if these records seem plaus...

On this week’s programme we talk to Clare Griffiths from the UK’s coronavirus dashboard and Alexis Madrigal from the Atlantic Magazine’s Covid Tracking Project in the US.

Many countries recently decided to suspend the use of the AstraZeneca coronavirus vaccine over fears it was increasing the risk of blood clots. The European Medicines Agency and the WHO called on countries to continue using the vaccine but regulators in individual countries opted to be cautious, waiting for investigations to take place. But why? Tim Harford explores the risks of blood clots and we...

A widely reported study claims that 90% of Covid 19 deaths across the world happened in countries with high obesity rates. While an individual’s risk of death is increased by having a high Body Mass Index, the broader effect on a country’s death rate is not what it seems.

Tim Harford explores the chances of becoming a saint, inspired by a throw away comment by the detective on the TV drama ‘Death in Paradise.’ Plus, a listener has a question about the recent Europa League Draw for the final knockout round. He spotted that none of the teams face a rival from their own country. What were the chances of that happening?

Cases of Covid 19 began to soar in the US in the autumn. By early January there were around 300,000 new cases a day. But since then the numbers have fallen steeply. What caused this dramatic drop? From herd immunity to the weather, Tim Harford explores some of the theories with Derek Thompson of The Atlantic magazine and Professor Jennifer Dowd, deputy director of the Lever Hume Centre for Demogra...

Are different countries counting deaths from Covid 19 in the same way? Tim Harford finds out if we can trust international comparisons with the data available. We discover Peru currently has the most excess deaths per capita over the course of the pandemic, while Belgium has the highest Covid death count per capita. Tim speaks to Hannah Ritchie from Our World in Data and John Burn Murdoch, senior...

The UK was the first European country to surpass 100,000 deaths from Covid 19. The UK has one of the worst death rates. But can we trust the numbers? Many of our listeners have asked us to investigate. Long Covid is widely acknowledged as being a growing problem, but what are the numbers involved? Just how many people have longterm symptoms after their initial infection? There have been reports th...

If we brought all the virus particles of the Sars-CoV-2 virus from every human currently infected, how much would there be? This was a question posed by one of our listeners. We lined up two experts to try to work this out. YouTube maths nerd Matt Parker and Kit Yates, senior lecturer in mathematical biology at the University of Bath, UK give us their best estimates. One believes the particles wou...

Are exports to the EU from the UK down 68% since Brexit? This apocalyptic statistic is being widely reported, but does it really tell us what’s happening at Dover and Folkstone? Ministers are tweeting reassuring numbers about flammable cladding on high rise buildings. We’re not so sure. Is it really true that one in five people are disabled? Plus, if you assembled all the coronavirus particles in...

Tim explores a shocking claim that life expectancy in some parts of Glasgow is less than it is in Rwanda. But is that fair on Glasgow and for that matter is it fair on Rwanda? And a listener asks whether loss of smell is a strong enough symptom of Covid that it might be used to help diagnose the virus, replacing rapid testing. Presenter: Tim Harford Producer: Chloe Hadjimatheou (Left: Rwanda refug...