To some on the internet, the cheap anti-parasitic drug Ivermectin is a potential wonder drug that could dramatically change the global fight against Covid-19. It has passionate proponents, from a small group of scientists to the more conspiratorially-minded. But with a scattered evidence base of varying quality, what - if anything - do we know for sure about Ivermectin? And is uncovering the truth a more complex process than some appreciate?With Gideon Meyerowitz-Katz from the University of Wollongong, Australia.Producer: Nathan Gower

The UK’s Covid cases are still rising and Scotland is being hit particularly hard - so are we speeding up our vaccination programme in response?Will many of the UK’s coastal towns, not to mention central London, be underwater in the next few years?Do the country’s poorest households really pay more than half their income in tax?What are the top five places with the best vaccination rates in the world? The answers may surprise you.We speak to Tom Chivers, a science journalist who has written a book called “How to Read numbers” with his cousin the economist David Chivers.

This year sees the delayed 400th anniversary celebrations of the Mayflower voyage, an event seen as a crucial moment in the history of the United States. But how many people alive today can trace back their lineage to those first 102 passengers? Tim speaks to Rob Eastaway and Dr Misha Ewen about maths and the Mayflower.

The Delta variant is behind the big increase in the number of new Covid 19 cases in the UK since April. We take a look at what impact vaccines have had on infections, hospitalisations and deaths.Chris Packham told viewers on the BBC’s Springwatch that blue tits eat 35 billion caterpillars a year. We get him onto the programme to explain.How much does Type 2 diabetes cost the NHS a year? While exploring a dubious claim we find out why its hard to work that out.Is it true that on in two people will get cancer? We’ve looked at this statistic before but listeners keep spotting it on TV.We also ask: if the SarsCov2 RNA is 96% similar to the RNA of a virus found in bats - is that similar, or not?

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 Secretary Matt Hancock has been in the news again with comments regarding care homes during the pandemic. Just how good was the government’s ‘ring of protection’ around care homes during the first wave - and the second? We speak to Steven Johnson about his book ‘Extra Life: A Short History of Living Longer.’

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 spoke to Steven about the numbers beneath possibly the most important number of all.

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 have spotted a potential discrepancy in the public data online.Are 80% of women wearing the wrong size bra? This frequently repeated statistic has been around for decades – could it possibly be true?

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 work out 28 + 47 in your head? We speak to mathematician Katie Steckles.A listener asked us to find out if it is true that the average age of a gamer is over 40.Plus, we take a look at this claim from Netflix documentary Seaspiracy: “if current fishing trends continue we will see virtually empty oceans by the year 2048.”

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 well, and why it doesn’t any more.Waiting lists for NHS treatment across the UK have grown – but why are things so bad in Northern Ireland?Is it true that 42% of young people are living at home with their parents? We find out what a young person is and why they haven’t flown the nest.

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 the confirmed Covid 19 deaths.

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 identified following the Astra Zeneca jab. How does pregnancy compare?

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 clots and asking why this level of risk is tolerated. Is this comparison fair? Tim Harford speaks to Professor Frits Rosendaal from the University of Leiden in the Netherlands and Susan Ellenberg, professor of biostatistics at the University of Pennsylvania.

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 plausible.

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 weighing up whether it was necessary to suspend using the vaccine.

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 Demographic Science at the University of Oxford.

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 data visualisation journalist at the Financial Times.

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 that we are drinking more in Lock Down. We examine the evidence. Dr Natalie MacDermott was one of the first guests invited on to More or Less to talk about the new coronavirus early last year. We revisit what she said then and what we know now. Plus, she tells of her own struggles with Long Covid.

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 would fit into a small can of coke, the other a spoonful.

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 the world into a pile - how big would it be?

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 refugee - photo Reza. Right: Glasgow homeless man - photo Christopher Furlong / both Getty images)

Prominent Labour politicians have claimed teachers are more likely to catch Covid-19, is that true?England’s Test and Trace programme has been widely criticised, has it raised its game in recent months? A ferocious row has broken out between scientists about how effective fast turnaround Lateral Flow tests are, and how they should be used. We examine the data.Plus, we examine a claim from Extinction Rebellion that British butterflies have declined by 50% since 1976.

A ferocious row has broken out among scientists about new coronavirus tests. Lateral flow tests provide results within minutes and some scientists believe they are offer accurate enough results at a speed that could allow us to resume business as usual. Others think they are so poor at detecting the virus that they could pose a huge danger.In this week’s More or Less, Tim Harford looks at the evidence and what we know about these new tests.

Since the start of the pandemic there have been many warnings that people might die not just from the coronavirus itself, but also if they didn’t seek medical help out of fear that hospitals might be dangerous. Is there any evidence that this has happened? David Spiegelhalter is on the case.The UK is in lockdown, but tens of thousands of people a day are still testing positive for Coronavirus. Where are they catching it? Grim data on drug deaths in Scotland has been called into question on social media. We ferret out the truth. Plus, what can venomous snakes tell us about the government's plan to increase the number of people self-isolating?

Since the start of the pandemic there have been many warnings that people might die not just from the coronavirus itself, but also if they didn’t seek medical help out of fear that hospitals might be dangerous. Is there any evidence that this has happened? David Spiegelhalter is on the case.The UK is in lockdown, but tens of thousands of people a day are still testing positive for Coronavirus. Where are they catching it? Grim data on drug deaths in Scotland has been called into question on social media. We ferret out the truth. Plus, what can venomous snakes tell us about the government's plan to increase the number of people self-isolating?

GDP figures for the period covering lockdown appear to show that the UK suffered a catastrophic decline, worse than almost any other country. But as Tim Harford finds out, things aren’t quite as bad for the UK as they might seem - though they might be worse for everywhere else. Also, alarming claims have been circulating in the UK about the number of suicides during lockdown. We look at the facts.There is support for the issues discussed in the programme at help.befrienders.orgPresenter: Tim Harford Producers: Nathan Gower and Chloe Hadjimatheou(Robots work on the MINI car production line at the BMW plant in Cowley, Oxford, UK. Credit: Tolga Akmen/ Getty Images)

The vaccine rollout continues: how long will it take before we see the benefits, and what benefits will we see? Figures suggest the UK’s economy performed worse than almost anywhere else in the world during the pandemic. But are the numbers misleading us? Alarming claims have been circulating about the number of suicides during lockdown. We look at the facts. Plus, will UK fishing quotas increase two thirds in the wake of Brexit? We trawl through the data.

A lot has changed since More or Less was last on air. We give you a statistical picture of the second wave: how bad is it, and is there hope? The new vaccine regime is to delay the booster shot of the Pfizer vaccine for up to 3 months. But is the first dose 52% or 90% effective? A new virus variant is meant to be 70% more transmissible, what does that mean? Plus, one of our youngest loyal listeners has a question about her classmates names.

What can ants tells us about whether something deserves to be popular? This is a question tackled in David Sumpter’s book – ‘The Ten Equations that Rule the World: And How You Can Use Them Too.’ He tells Tim Harford about some of the algorithms that you see in nature, and those harnessed by tech companies such as YouTube.

From the economic impact of Covid 19 to the number of people who have access to soap and water, we showcase figures that tell us something about 2020. Tim Harford asks a group of numbers-minded people to take a look back on the year and think of one statistic that really stands out for them. We speak to Razia Khan, the head of research and chief economist for Africa and the Middle East at Standard Chartered; Sana Safi, presenter for BBC Pashto TV at the BBC's Afghanistan Service; and Jennifer Rogers, vice president for external affairs at the Royal Statistical Society. Presenter: Tim Harford Producer: Charlotte McDonald

Tim Harford asks a group of numbers-minded people to take a look back on the year and think of one statistic that really stands out for them. From the spread of Covid-19 to the number of songs added to Spotify this year, we showcase figures that tell us something about 2020. We speak to Oliver Johnson, professor of information theory at the University of Bristol in the UK; Anne-Marie Imafidon, creator and CEO of social enterprise Stemettes; and economist Joel Waldfogel, of the University of Minnesota.

Tim Harford asks economist Joel Waldfogel how Covid 19 could affect spending at Christmas this year. They discuss the usual bump in sales and gift giving. The author of ‘Scroogenomics’ usually argues that presents are rarely as valued by the recipient compared to something they might buy for themselves. But what should people do this year?

Tim Harford looks at false statistical claims online about missing and trafficked children in the US. These numbers have resurfaced online in part due to conspiracy theorists following QAnon. In the past few months they have inspired protests under the banner - ‘Save Our Children’. We wade through some of the false numbers with the help of Michael Hobbes, a reporter for Huff Post and the co-host of the podcast called You're Wrong About.

The UK has become the first country in the world to approve the use of a vaccine for Covid 19. But some people are worried that the decision was taken too quickly - can we really know it’s safe yet? Tim Harford tackles these safety concerns. Plus, what is the best way to distribute the vaccine? How do you maximise the benefit of the first round of vaccines? Stuart McDonald, a fellow of the Institute and Faculty of Actuaries in the UK works out what groups would benefit most.

This year has shown us the importance of good robust data - as Covid-19 spread around the world it was vital to track where it was, how many people it was infecting and where it might go next. On More or Less we’ve spent months reporting on data inaccuracies and vacuums, but what makes for good or indeed bad data? I’ve been speaking to Amy Maxmen, Senior reporter at the scientific journal ‘Nature’ about which countries are getting data collection right and which aren’t.

If you go to a gathering of 25 or more people, what are the chances one of you has coronavirus?Imagine that you’re planning to hold some sort of gathering or dinner at your home. Take your pick of big festivities - it’s Thanksgiving in the US, we’ve just had Diwali and Christmas is on the horizon. In some places such a gathering is simply illegal anyway. But if it IS legal, is it wise?Professor Joshua Weitz and his team at Georgia Tech in the US have created a tool which allows people in the US and some European countries to select the county they live in, and the size of gathering they are intending on having, and then it calculates the chances that someone at that party, has Covid 19.Presenter: Tim Harford Producer: Charlotte McDonald

A vaccine which has shown in a clinical trial to be 90% effective against Covid 19 has been widely welcomed. But what does it mean and how was it worked out? Although experts and politicians urge caution, how excited can we be about the results of this trial of the vaccine developed by Pfizer and BioNTech? Tim Harford explores what we know about this new vaccine candidate with Jennifer Rogers, vice president of the Royal Statistical Society in the UK, and she also works for Phastar, a consultancy which specialises in analysing clinical trials. Presenter: Tim Harford Producer: Charlotte McDonald

Tim Harford explores what we know about mortality rates in the current pandemic. We discuss the differences between the risks to different age groups, and why that has an effect on a country’s Covid 19 fatality rate. We speak to Dr Hannah Ritchie from the University of Oxford and Dr Daniel Howdon of the University of Leeds in the UK.

A headline in a British tabloid newspaper claimed that ‘Staggering 86% who tested Covid positive in lockdown had NONE of the official symptoms’ but what does this mean and is it true?

Tim Harford hears about the sheer volume of false claims made during the campaign. President Trump is well known for making wild statements, but has his behaviour changed? And what about Joe Biden? So much attention is concentrated on Trump’s claims, how does the Democratic candidate fare? Glenn Kessler at the Washington Post and Katherine J Wu at the New York Times tell us about fact-checking during the run up to the election.

Paul Milgrom and his former tutor Robert Wilson worked together for years developing ways to run complicated auctions for large resources. This month the two Stanford University professors were awarded the Nobel memorial prize in economics for their work. The auction formats they designed facilitated the sale of goods and services that are difficult to sell in a conventional way, such as radio frequencies.