Water used to cool nuclear reactors at the stricken Fukushima nuclear power plant in Japan is being released into the Pacific Ocean by Japanese authorities. The move has sparked protests and concerns about safety in the region and met with retaliation from near neighbour China. But how safe is the water that’s been released? Presenter Charlotte McDonald and reporter Calum Grewar investigate, with the help of Professor Jim Smith of the University of Portsmouth and Professor Gerry Thomas, formerly of Imperial College London and the Chernobyl Tissue Bank.Presenter: Charlotte McDonald Reporter: Calum Grewar Producer: Jon Bithrey Editor: Richard Vadon Sound Engineer: James Beard Production Co-ordinator: Brenda Brown

Butterflies are a much-loved feature of summer in many parts of the world. But how many of them are there on Earth? That’s the question a young listener to More or Less wanted an answer to – and she couldn’t find the answer no matter how hard she searched the internet.Presenter Daniel Gordon enlists Professor Jane Hill, a butterfly expert at York University, England, who’s also President of the Royal Entomological Society, to try and help solve the mystery.He also consults Holly Mynott, International Officer of Butterfly Conservation, who describes the techniques used to run The Big Butterfly Count in the UK – the biggest event of its kind in the world.Producer/Presenter: Daniel Gordon Series Producer: Jon Bithrey Editor: Richard Vadon Production Co-ordinator: Brenda Brown Sound Engineer: Graham Puddifoot

Football competitions are kicking off all around Europe in the coming days and weeks, including the world’s most watched division: The English Premier League. We might make our predictions on who we think is going to win a sporting competition but what factors are we considering? In this programme we look at some of the most popular variables that are taken into account when making sporting predictions and why even these have drawbacks. From upcoming football leagues to the Olympic Games, Head Analyst from Nielsen Gracenote, Simon Gleave tells us what are some of the most difficult sports to predict and why.Presenter: Paul Connolly Producer: Natasha Fernandes Editor: Richard Vadon Production Co-ordinators: Debbie Richford and Janet Staples Sound Engineer: Graham PuddifootImage: Premier League Trophy, Credit: Carl Recine/Reuters

Reports on heatwaves across the globe have dominated our newsfeeds over the last few weeks, with temperatures said to have soared over the 40C mark in many parts of Europe. But across social media, not everyone is buying it. A trickle of scepticism swelled to a tidal surge, with people questioning whether temperatures are being hyped up by the wider media to drive fear and scare-monger. In this programme, we unpick allegations made about how these temperatures are recorded - and if they are accurate. We hear from Samantha Burgess at the Copernicus Climate Change Service; Alessandro Delitala from the Sardinia Environmental Protection Agency; and Sean Buchan from Climate Action Against Disinformation. Presenter: Paul Connolly Producer: Natasha Fernandes Editor: Richard Vadon Production Co-ordinator: Brenda Brown Sound Engineer: Rod Farquhar

Recent global headlines have been dominated by record temperatures across Europe, North America and parts of Asia. As extreme weather events have happened for decades, how are links to climate change made? In this programme we look at how scientists use data to draw climate conclusions and hear how that data isn’t always available, with a focus on severe flooding earlier this year in part of Central Africa. With Joyce Kimutai, principal meteorologist and climate scientist at the Kenya Meteorological Department and researcher at the Grantham Institute for Climate Change, Imperial College.Presenter: Kate Lamble Producer: Nathan Gower, Jon Bithrey Editor: Simon Watts Production Co-ordinator: Brenda Brown Sound Engineer: Graham Puddifoot

Official information on the numbers of dead and injured in the Ukraine war has been in short supply. Little has come from either the Ukrainian or Russian sides, with estimates from western governments and intelligence agencies filling the information void. But some Russian journalists have been documenting war deaths and have come up with a new way of estimating fatalities using probate records. With contributions from David Frenkel, reporter at Mediazona and the BBC’s Russian Service correspondent Olga Ivshina.

Japan has one of the highest rates of life expectancy and one of the lowest birth rates. But does that mean that a widely circulated claim – that more nappies aimed at adults are sold in Japan than those made for babies – is true? With guests Sarah Parsons, Senior Teaching Fellow at SOAS in London and Dr Mireya Solis, Knight Chair in Japan Studies at the Brookings Institution.Presenter: Charlotte McDonald Reporter: Isobel Gough Producers: Isobel Gough, Jon Bithrey Sound Engineer: James Beard Production Co-ordinator: Brenda Brown

Various claims have been made about how much water is used in the production of a pair of jeans, that cornerstone of casual clothing. With growing worries over the environmental impact of denim production, More or Less decided to investigate - with the help of journalist and researcher Elizabeth L. Cline who has written extensively on sustainability and the fashion industry. This programme was first broadcast in July 2022. Presenter: Tim Harford Producers: Lizzy McNeill, Jon Bithrey Programme Coordinator: Brenda Brown Sound engineer: Neil Churchill Editor: Richard Vadon (A worker sews blue jeans in a textile company in Xintang, China, dubbed the 'denim jeans capital of the world'. Photo: Lucas Schifres/Getty images)

More than 1.2 million people came into the country to stay for more than 12 months in 2022. As only 560,000 left the country, this means net migration is at an all-time high. Both the Prime Minister and Home Secretary have said the number of people coming needs to come down. But who counts as an immigrant? How are the figures worked out? Charlotte McDonald will be finding out what the numbers tell us about who is coming to the UK and why. Plus - what about the people who left in 2022?

An article on the UK’s Telegraph newspaper website claimed that there would be just 6 grandchildren for every 100 South Koreans today. We ask whether that figure is correct and look at why South Korea’s birth rate has fallen to one of the lowest in the world, with the help of author and mathematician Rob Eastaway and journalist and author Hawon Jung.Presenter: Tim Harford Producers: Bethan Ashmead Latham, Jon Bithrey Editor: Richard Vadon Production Co-ordinator: Brenda Brown Sound Engineer: James Beard

One of Rishi Sunak's five priorities for 2023 is to halve inflation. Given prices are still rising, we discuss whether it's going be possible. Also does Scotland have more tidal power capacity than the rest of the world combined, as has been claimed? We look at competing claims about how prepared the NHS was before the pandemic, ask whether scrapping VAT on products like tampons and e-books has actually benefitted consumers and look at the claim that one in three women in the UK has had an abortion.

‘This episode was updated on 26th June to remove an error in how we quantified 32 trillion dollars’ The level of US government debt has just surpassed 32 trillion dollars. Negotiations over raising the borrowing limit once again went down to the wire a few weeks ago. But how concerned should we all be about how much the US government borrows? We investigate with the help of Kent Smetters, professor at the Wharton School of the University of Pennsylvania and Betsey Stevenson, Professor of Economics and Public Policy at the University of Michigan.

Mortgage rates have risen to 6%. But are things as bad as when rates were much higher in the 1970s and 80s? We look at just how much pain today's rises mean. Also will there be just 6 grandchildren for every 100 South Koreans today? And we look into a claim that the space industry supports 18% of the UK's economy.Presenter: Tim Harford Series Producer: Jon Bithrey Reporters: Beth Ashmead Latham, Nathan Gower, Charlotte McDonald Sound Engineer: James Beard Production Co-ordinator: Brenda Brown

A new study by researchers at Oxford University has linked better exam results at school with being breastfed as a baby. But how much faith can we put in the findings? Tim Harford speaks to Emily Oster, professor of economics at Brown University in the US and the author of three books about pregnancy and parenting.

There's been a lot of coverage about the risks electric cars may pose to infrastructure like bridges and car parks. We look at how much heavier EVs are. Plus we look at a new study that suggests a link between breastfeeding and improved grades at GCSE level. Also is throat cancer now primarily caused by a sexually transmitted disease - and are 600 million bottles going to litter Scotland because of disagreements with the UK government over the new Deposit Return Scheme?

How prevalent is hunger and malnutrition in India? With Indian data journalist Rukmini S, we interrogate recent claims that hunger has worsened dramatically in recent years, and explore how malnutrition affects child mortality in the world’s most populous country.Presenter: Tim Harford Producer: Nathan Gower Editor: Richard Vadon Programme Coordinator: Brenda Brown Sound Engineer: Neil Churchill

The Liberal Democrats say 120 people a day in England died last year whilst waiting for an ambulance. We investigate whether the claim stands up to scrutiny. Also Rishi Sunak's pandemic-era scheme Eat Out To Help Out is back in the spotlight. How much did it really contribute to a second wave of infections? We look at a claim that no single woman in England on an average salary can afford to rent a home of her own. And Jonathan Agnew said on Test Match Special that goat is the most eaten meat in the world. Is he right?Presenter: Tim Harford Series Producer: Jon Bithrey Reporters: Jo Casserly, Nathan Gower Editor: Richard Vadon Sound Engineer: James Beard Production Co-ordinator: Brenda Brown(Woman looking for a flat to rent. Credit: Oscar Wong/Getty images)

We live in a world where data is everywhere – informing if not governing our lives. But this wealth of data didn’t just turn up overnight. Tim Harford talks to academics Chris Wiggins and Matthew Jones, whose new book How Data Happened aims to explain how the world we know today has been shaped by not just technological developments but battles around how emerging sources of data should be utilised.

Does Britain really have the most affordable food in Europe? That's a recent claim of the President of the National Farmers' Union. We ask if it's true and look in detail at what is driving rising food prices in the UK. We also try and make sense of the latest net migration figures, ask if dating apps are making Gen Z more single and explain why a correction to a correction on Radio 4's Farming Today wasn't quite right.

What’s the definition of being single – and how easy is it to measure? There’s a perception that young people today are more single – in a relationship sense - than ever, and dating apps are to blame. But how true is that? Ellie House investigates, with the help of Marina Adshade of the Vancouver School of Economics. Presenter: Ellie House Producers: Ellie House, Jon Bithrey Editor: Richard Vadon Sound Engineer: Rod Farquhar Production Co-ordinator: Brenda Brown

The government has trumpeted a big fall in those waiting over 18 months for hospital treatment in England. But total numbers on waiting lists have hit a new high. Also we look at how much impact the introduction of Voter ID had on turnout in May's English local elections. We ask whether Portugal really has a divorce rate of 94%. And we remember mathematician Dr Vicky Neale of Oxford University, who has died at the age of 39. The government has trumpeted a big fall in those waiting over 18 months for hospital treatment in England. But total numbers on waiting lists have hit a new high. Also we look at how much impact the introduction of Voter ID had on turnout in May's English local elections. We ask whether Portugal really has a divorce rate of 94%. And we remember mathematician Dr Vicky Neale of Oxford University, who has died at the age of 39.Presenter: Tim Harford Series Producer: Jon Bithrey Reporters: Josephine Casserly, Octavia Woodward, Ellie House Sound Engineer: James Beard Production Co-ordinator: Brenda Brown

For more than a decade there’ve been longstanding concerns about the credibility and reliability of science research. This “bad science” has often stemmed from poor data practice or worse. But statistics can also help us identify and understand some of what’s going wrong, whether that’s selective data-slicing or outright fabrication.Tim Harford talks to writer and broadcaster Michael Blastland about his new BBC radio documentary ‘The Truth Police’, which hears from the outsiders who are calling out fraud, malpractice and incompetence in science.Presenter: Tim Harford Producer: Nathan Gower Editor: Richard Vadon Programme Coordinator: Brenda Brown Sound Engineer: James Beard

Portugal has a divorce rate of 94% and India just 1%, according to a social media post about divorce in 33 countries that has gone viral. But how are these figures calculated and what do they really tell us about the quality and endurance of marriage? We investigate with guests Marina Adshade, assistant professor at the Vancouver School of Economics and Dr Cheng-Tong Lir Wang of the Institute for the Future in San Francisco.Presenter: Ben Carter Producers: Octavia Woodward and Jon Bithrey Editor: Richard Vadon Production Co-ordinator: Brenda Brown Sound Engineer: Neil Churchill

The average life expectancy of Americans is shrinking at an alarming rate. Between 2019 and 2021, a staggering 2.7 years has been shaved off, leaving the revised figure at 76.1 years - the lowest it’s been in more than two decades. It also sees the U.S. rank 46th in the global life expectancy charts, behind Estonia and just a nose ahead of Panama. Paul Connolly is joined by John Burn Murdoch, Mary Pat Campbell and Dr Nick Mark to discuss why, on average, citizens of the world’s richest country are dying so young.

Consisting of 2 kilograms of gold and 444 gemstones, the iconic St Edward’s Crown will play a central role in the coronation of King Charles III, as it has for many of his predecessors. There has been much speculation as to what the value of the centrepiece of the Crown Jewels really is. Charlotte McDonald talks to Dr Anna Keay, historian and author of The Crown Jewels - the Official History, and Alan Hart, CEO of the Gemmological Association of Great Britain. Together they break down what we know about the crown’s cost to make in the 17th century and what it might be worth today.

The leaking of US intelligence documents and the arrest of a 21 year old airman who authorities believe to be responsible has caused a media and diplomatic storm. We look at how the leaks were reported by primetime Fox News host Tucker Carlson, who said seven Ukrainian troops are dying for every one Russian, contrary to most estimates. And we examine an advert Fox News took out claiming to be the American TV network most trusted for news. With guests Aric Toler from investigative journalism site Bellingcat, data journalist and author G. Elliott Morris and BBC correspondent Olga Ivshina.

Paul Connolly is expecting his second child, and the due date is just under two weeks away. In hopes of easing his anxiety every time the phone rings , he is joined by Professor Asma Khalil, Professor Chris Pettker and Doctor Melissa Wong to discover exactly how accurate his baby's due date is...Presenter: Paul Connolly Researcher: Octavia Woodward Editor: Richard Vadon Sound Engineer: Graham Puddifoot Production Co-ordinator: Brenda Brown

The covid-19 pandemic has brought the use of statistics into everyday life in a way never seen before. Tim Harford talks to Professor Oliver Johnson, author of Numbercrunch: A Mathematician’s Toolkit for Making Sense of Your World, about his visual presentation of covid-19 related figures on Twitter and how we can all improve our understanding and use of numbers.

Pythagoras’ Theorem, explaining the relationship between the three sides of a right angled triangle, is one of the most famous in maths. It’s been studied and put to use for thousands of years. Now two US high school students say they’ve found a new trigonometric proof for the theorem, something many in the mathematical community believe to be impossible. We discuss Pythagoras’ Theorem, the importance of proofs in maths and the chances of this being a real breakthrough with mathematician, author and YouTuber Matt Parker.

Misinformation around covid-19 and vaccines is rife and as the data available increases, so do often misleading and even wild claims. This week More or Less examines multiple viral claims that the Covid 19 mRNA vaccines increase the risk of miscarriage. To explain where these incorrect figures come from and what the science actually tells us, we are joined by Dr Viki Male, senior lecturer in reproductive immunology at Imperial College London. Presenter: Charlotte McDonald, Producers: Octavia Woodward and Jon Bithrey Editor: Richard Vadon Sound Engineer: John Scott Production Co-ordinator: Helena Warwick-Cross(Photo by Matthew Horwood/Getty Images)

After the collapse of Silicon Valley Bank sent jitters through the financial system, Duncan Weldon explains how it’s just the latest in the long history of bank runs.He talks to financial analyst and former banking regulator Dan Davies - author of ‘Lying for Money’ - to understand how bank runs happen, and what the repercussions of this very modern bank run might be for the global financial system. Presenter: Duncan Weldon Producer: Nathan Gower Editor: Richard Vadon Programme Coordinators: Helena Warwick-Cross Sound Engineer: Neva Missirian(Photo credit: Reuters)

The smash hit TV show and video game ‘The Last of Us’ has spawned lots of curiosity about how worried we should be about the relatively unknown world of fungi. A figure in a recent BBC online article stated that fungal infections kill around 1.7 million people a year, about three times as many as malaria. In this episode we look at the both the global fight against malaria and David Denning, Professor of Infectious Diseases and Global Health at the University of Manchester explains the risks posed by fungal infections globally.

The Brink’s-Mat robbery remains to this day one of Britain’s biggest and most audacious heists. Six armed men stole diamonds, cash and three tonnes of gold bullion from a warehouse close to London’s Heathrow Airport in November 1983. It’s now the subject of a BBC television drama, The Gold, which includes the claim that most gold jewellery bought in the UK from 1984 onwards will contain traces of that stolen gold. But how true is that? Tim Harford and team investigate, with the help of Zoe Lyons from Hatton Garden Metals and Rob Eastaway, author of Maths on the Back of an Envelope.

Does the UK really have by far the highest domestic energy bills in Europe? We debunk a viral social media claim suggesting just that. Also the number of excess deaths has been falling in the UK - how positive should we be that we’re through the worst? Plus do we really have access to only 3% of rivers and 8% of the countryside in England – and after the conviction of former MP Jared O’Mara we ask whether 5 grams of cocaine is a lot.

How environmentally destructive is our thirst for coffee? Tim and the team investigate a claim that 29,000 coffee pods end up in landfill globally every minute with the help of Dr Ying Jiang, a senior lecturer in bioenergy from Cranfield University in the UK.

The Justice Secretary Dominic Raab says crime reoffending rates in England and Wales have fallen significantly since the Conservatives came to power. We ask whether he’s right and look more broadly at crime and conviction rates with former BBC home affairs correspondent Danny Shaw. Also we look at how much taxes in Wales might have to rise to pay for increases in NHS funding. We ask whether 13 million women in the UK are really menopausal. And we return to the debate that has sparked consternation among loyal listeners everywhere – should the word data be treated as plural or singular.

Florence Nightingale became one of the icons of Victorian Britain for her work as a nurse during the Crimean War and the public health improvements she successfully campaigned for later on. Tim Harford discusses how she and her ‘Nightingale Circle’ used spectacular diagrams to explain health statistics persuasively with RJ Andrews, editor of “Florence Nightingale, Mortality and Health Diagrams”.

How much do nurses in the UK earn compared with those elsewhere in Europe? Tim Harford and the team investigate. Also we have an update on ambulance response times, which were the worst on record in December but are showing signs of improvement. Should we use the word data in the singular or plural? The Financial Times has just changed its policy and Tim’s not happy. We look back at women who have made a key contribution to economics but have often been forgotten. And we hear how a spreadsheet error by the Office for National Statistics made the UK’s productivity appear to be one of the fastest improving in Europe.

The UK’s Office for National Statistics recently published some dramatically incorrect data - all because of a spreadsheet slip-up. But that’s just the most recent in a long list of times when spreadsheets have gone wrong, often with costly consequencesStand-up mathematician Matt Parker takes us through a short history of spreadsheet mistakes.

The International Monetary Fund says the UK will be the only major economy to shrink in size this year. We ask how much faith we should put in the IMF’s forecasts and look at some of the big economic challenges facing the UK. Also why the headline number of job vacancies in the NHS in England doesn’t tell the whole story of staff shortages. And why has there been such a dramatic change in whether people describe themselves as British or English?

A new study led by Imperial College in London suggests that data from loyalty card spending in supermarkets and pharmacies could be used as a way of detecting ovarian cancer much earlier. Tim Harford discusses the findings with Professor Hannah Fry, who was most recently on the show talking about her own experience with cancer.

Has trade with the EU increased since Britain left the European Union? Tim Harford and the team look at a claim suggesting just that. There’s a row over the renaming of a street in North London previously called Black Boy Lane – but how much has it really all cost? Also are there more pensioners in “millionaire households” than pensioners in poverty. And mathematician Hannah Fry talks about a new study suggesting cases of ovarian cancer can be detected by looking at spending on loyalty cards.

A widely respected and cited study says humans and livestock account for 96% of all mammals on Earth. We ask how the study was carried out and what hope there might be for the future. Plus we answer another listener question about whether most mammals are in fact rodents. With the help of Dr Hannah Ritchie, Deputy Editor at Our World in Data and Dr Axel Rossberg, Reader in Theoretical Ecology at Queen Mary University of London.

Jeremy Hunt has pledged in a new social media video to halve the UK’s high rate of inflation. Tim Harford and the team fact check the Chancellor’s claims. Also – CPI, CPIH, RPI – which measure of inflation is best for assessing the impact of the rising cost of living? Plus has the number of GPs in England gone up or down since the start of the pandemic. And does toilet paper cause 15% of global deforestation?Presenter: Tim Harford Series Producer: Jon Bithrey Reporters: Josephine Casserly, Nathan Gower, Louise Hidalgo, Charlotte McDonald Sound Engineer: James Beard Production Co-ordinator: Helena Warwick-Cross Editor: Richard Vadon

A British company has claimed that the production and use of toilet paper is responsible for 15% of deforestation globally. We investigate the claim and ask what the true environmental cost of toilet paper is. Charlotte McDonald talks to climate change scientist Professor Mary Gagen, chief adviser on forests to the World Wide Fund for Nature, the WWF.Presenter: Charlotte McDonald Producer: Louise Hidalgo and Jon Bithrey Editor: Richard Vadon Production Coordinator: Helena Warwick-Cross Studio Engineer: Rod Farquhar

How long are people really waiting when they call 999 for an ambulance? Tim Harford and the team examine in detail the sheer scale of delays in responding to emergency calls. We also ask why the NHS is facing a crisis when it’s got more funding and more staff than before the pandemic, with the help of Ben Zaranko from the Institute for Fiscal Studies. Plus we fact check a claim from one of Britain’s leading teaching unions about pay. And are there more pubs in Ireland or Irish pubs in the rest of the world?Presenter: Tim Harford Series producer: Jon Bithrey Reporters: Josephine Casserly, Nathan Gower, Paul Connolly Sonic Landscape: James Beard Production Co-ordinator: Helena Warwick-Cross Editor: Richard VadonImage: Andy Rain/EPA-EFE/REX/Shutterstock

How did an edition of More or Less from 2017 end up influencing the choice of official names for extremely large numbers? We tell the tale of how an interview between presenter Tim Harford and maths whizz Rob Eastaway did just that. Also featuring Professor Richard Brown, head of metrology at the UK’s National Physical Laboratory.Presenter: Tim Harford Producer: Jon Bithrey Editor: Richard Vadon Production Coordinator: Janet Staples Sound Engineer: James BeardImage: Large number, Credit: Getty Images

Tim Harford and the team return for a new series of the number crunching show. With the huge pressures facing the NHS we ask how many people may be dying because of treatment delays in A&E. We hear what the latest census tells us about changing religious identity in Northern Ireland. We look at misleading claims about covid vaccines after the collapse of American football player Damar Hamlin. And we hear how More or Less has wielded its influence over how we all describe very large numbers.Presenter: Tim Harford Series producer: Jon Bithrey Reporters: Nathan Gower, Louise Hidalgo, Charlotte McDonald Production Coordinator: Brenda Brown Sound Engineer: James Beard

When the pandemic took hold, the Chinese government imposed a zero-Covid policy that aimed to contain the virus through mass-testing and strict lockdowns. But early in December, amidst widespread public protests and the spread of the omicron variant to more than 200 cities, those draconian, highly restrictive measures were lifted almost entirely. For the first time in just under two years, the majority of the country’s near one-and-a-half billion citizens were free to meet, mix and mingle where they pleased, triggering what experts believe is a gargantuan wave of covid infections and related deaths. Some analysts say death rates could be as high as15,000 per day. But the Chinese authorities are reporting five or fewer deaths a day. The numbers don't stack up so More or Less's Paul Connolly speaks to some of the world's leading experts and epidemiologists to work out if China's data on covid deaths can be trusted - and, if not, what the real death toll could be.