More or Less

Tim Harford speaks to Persi Diaconis, top professor of maths and statistics and legendary magician. The Stanford University professor and co-author of the book "Magical Mathematics" has an enthralling story to tell of how he discovered magic as a boy, and then, as a consequence, a love of maths. And to illustrate how closely maths and magic are linked, Crossing Continents editor and the BBC's in-house magician, Hugh Levinson, performs a mathemagical card trick - see the performance below. This programme was broadcast on the BBC World Service. The interview was recorded in 2011.

If all the world’s population crowded together, where could we all fit? London? Texas? More or Less figures it out, and separates fact from fiction. And, as the soccer season returns, is it possible to measure the effectiveness of a team’s manager? We hear from David Sally, author of The Numbers Game. This programme was first broadcast on the BBC World Service.

This week we find out what the most visited country in the world is and ask why aren’t they capitalising financially as well as their rivals. Plus we also investigate the complex - and often controversial - web of international extradition treaties. The programme hears from extradition lawyer Anand Doobay, from Peters and Peters, and Ted Bromund, a senior research fellow in Anglo-American relations in Washington DC. This programme was first broadcast on the BBC World Service.

The winner of this year's Tour de France, British rider Chris Froome, faced numerous questions about doping during the course of his victory. More or Less assesses his performance stats, and asks whether maths can measure whether cycling really has cleaned up its act and whether Froome is simply a victim of the ghosts of cycling's past. Dr Ross Tucker from The Science of Sport website gives us his views and we hear from physiologist Fred Grappe - the only man to see Froome's tour data. This programme was first broadcast on the BBC World Service.

It’s claimed that Egyptians have taken part in the biggest uprising the world has ever seen. The nationwide demonstrations, which were followed by the removal of the president by the army, were certainly a massive show of people power. But were the crowds really as large as reported? Ruth Alexander assesses the evidence, and finds out why it is so difficult to count a crowd. This programme was first broadcast on the BBC World Service.

The world of porn is often exaggerated but does it really make up 37% of the web? And after some high profile cases we ask whether the American football league has a crime problem? This edition was first broadcast on the BBC World Service.

Life expectancy at birth around the world has increased by six years in the past two decades. But can this striking trend continue? Ruth Alexander looks at the data. This edition was first broadcast on the BBC World Service.

Ruth Alexander examines US Secretary of State, John Kerry’s claim that 40% of the world’s workforce will be in Africa by 2050 and talks to the chief of the United Nations’ population division about its projections for 2050 and 2100. The programme also examines the final scene in The Fast and the Furious 6, the global box office sensation. How long must that runway have been at the end of the film? This programme was first broadcast on the BBC World Service.

Ruth Alexander examines the claim that every 15 seconds a child dies of hunger. It’s a popular statistic used by celebrities and charity campaigners in support of the Enough Food for Everyone IF campaign. It conjures up the image of millions of young children starving to death. But is this really the case? This programme was first broadcast on the BBC World Service.

Parents take note – what can numbers reveal about bringing up children? Plus, Tim Harford explore if men really do think about sex every seven seconds. This urban myth will not go away and yet pinning down any evidence proves a challenge for the More or Less team.

A&E waiting times have been making the headlines - Tim Harford takes a look at some of the numbers and puts them into context. Today presenter Evan Davis explains his frustration with finding official statistics online. We explore if men really do think about sex every seven seconds. Plus, what are the chances of having twins?

In the wake of the Boston Marathon bombing and the killing of a British soldier on the streets of Woolwich in London, it emerged that the suspects were known to the security services. But how feasible is it for the authorities to keep track of everyone on their watch list? Tim Harford crunches the numbers, with the help of the former head of the UK intelligence service MI5, Dame Stella Rimington.

After the killing of a British soldier on the streets of Woolwich in London, it emerged that the suspects were known to the security services. But how feasible is it for the authorities to keep track of everyone on their watch list? Tim Harford crunches the numbers, with the help of the former head of MI5, Dame Stella Rimington. Plus: a listener requests a cost-benefit analysis of kidney donations; and Johnny Ball gives the Apprentices a maths lesson.

Tim Harford examines Ryanair’s claim that more than 90% of its flights land on time; and discovers that millions of scientific papers may be incorrect. Producer: Ruth Alexander

Tim Harford inspects the claims the UK Treasury and the Scottish government make about the economics of an independent Scotland; tests Ryanair’s claim that more than 90% of its flights land on time; re-runs the Eurovision song contest, excluding the votes of the former Soviet countries to test whether political alliances are affecting the final results; discovers that millions of scientific papers may be incorrect; and learns more about dog years – and cat years.

As Angelina Jolie announces that an 87% cancer risk has prompted her to have a double mastectomy, Tim Harford assesses the probabilities associated with the disease. Plus, has the UK been hit by a Romanian crime wave?

As Angelina Jolie announces that an 87% cancer risk has prompted her to have a double mastectomy, Tim Harford assesses the probabilities associated with the disease. Plus, has the UK been hit by a Romanian crime wave? Also in the programme: Education Secretary Michael Gove’s use of PR surveys; and why the UK’s poor growth has not had led to the high levels of unemployment that economists would expect.

It's often said that one dog year equals seven human years. But is it true? Tim Harford and Ben Carter unveil the More or Less Dogulator. Plus, 15 distant relatives of England’s King Richard III are petitioning the High Court about where the king should be buried. Some reporting has implied that the famous 15 are almost the only descendants of Richard III who exist. But mathematician Rob Eastaway figures out how many other relatives of Richard III might actually be out there.

Tim Harford makes sense of the numbers being used in the political battle about the UK and its membership of the EU. And, he looks at whether it’s true that more war veterans kill themselves than die in combat ; why you could well be a descendant of Richard III; and what Margaret Thatcher’s funeral really cost. Plus, is it true that one dog year equals seven human years? Tim unveils the More or Less Dogulator.

Birds + windows =? The BBC Quiz show The Unbelievable Truth reckons that more than 2 million birds die crashing into window panes every day in the US. Tim Harford finds this, well, unbelievable. Marcus du Sautoy explores the maths in Mozart's The Magic Flute; a student who uncovered a mistake in a famous economic paper, which has been used to make the case for austerity cuts, explains how he did it.

Birds + windows =? The BBC Quiz show The Unbelievable Truth reckons that more than 2 million birds die crashing into window panes every day in the US. Tim Harford finds this, well, unbelievable. Marcus du Sautoy explores the maths in Mozart's The Magic Flute; a student who uncovered a mistake in a famous economic paper, which has been used to make the case for austerity cuts, explains how he did it; and separating fact from fiction about Margaret Thatcher with a look at the numbers of her time in office.

More or Less creates the Alternative Premier League, with lead scorer goals chalked off to work out whether it’s true that Van Persie’s really single-handedly won Manchester United’s the League? And would Tottenham be challenging for a Champions League spot without Gareth Bale’s goals? And how much bite has Luis Suarez’s contribution given Liverpool’s season? There are surprises, and one player really stands out as player of the season. Can you guess who it is? And, as an Italian Court overturns the acquittal of Amanda Knox and Raffaele Sollecito, accused of killing student Meredith Kercher, mathematician and author of Math on Trial, Coralie Colmez, argues that one judge in the case failed to understand some of the probabilities attached to the forensic evidence – and, in doing so, has missed an opportunity to get to the truth of the matter.

Tim Harford tells the story of the student who uncovered a mistake in a famous economic paper that has been used to make the case for austerity cuts. In 2010, two Harvard economists published an academic study, which showed that when government debt rises above 90% of annual economic output, growth falls significantly. As politicians tried to find answers to the global economic crisis, “Growth in a Time of Debt” by Carmen Reinhart and Kenneth Rogoff was cited by some of the key figures making the case for tough debt-cutting measures in the US and Europe. But, in the course of a class project, student Thomas Herndon and his professors say they have found problems with the Reinhart-Rogoff findings. What does this mean for austerity economics?

Baroness Margaret Thatcher, who has died aged 87, was Britain’s first female prime minister and one of the most influential political figures of the 20th Century. She was a pioneer of free market economics, helping to spread the ideas around the world. But the Iron lady was a divisive figure with passionate supporters and critics. Both hold to strong beliefs about what she did. But what does the data tell us about the many claims made about Mrs Thatcher?

It’s the fourth anniversary of the earthquake which devastated the city of L’Aquila in Italy and which led to the conviction of six scientists and an official who failed to predict the disaster. Scientists and statisticians worldwide were alarmed at the six-year sentences for manslaughter the seven accused received. It was feared the prospect of being put on trial would put off scientists from even trying to communicate risk – a very difficult business. But the risk assessors’ pendulum seems to have swung the other way. Data and alarms about tremors are being issued regularly, triggering school closures and building evacuations. But how useful is this information? Ruth Alexander speaks to Ian Main, professor of seismology and rock physics at Edinburgh University in the UK, who puts the risks into context.

What if a super-villain took control of the world's gold a melted it in to a cube? How big would it be? Wesley Stephenson finds out.

With an avalanche of 2.5 quintillion bytes of data generated daily, could this be used to change our lives and does it have a darker side?

Only last week Ivory Toldson heard the speaker say there are more black men in prison in America than in college. ‘Here we go again’ he thought. Only the week before he had written his second article on why this statistic is not true. This week Ruth Alexander looks at where this ‘fact’ came from and why it is still being used. Also, why the opinion polls got the Kenyan elections wrong.

With the news that a baby has been ‘cured’ of HIV what do the numbers tell us about the epidemic. Ruth Alexander looks at the changes in the way that the disease has been measured. Also the Dow Jones hit an all-time high this week so is it party time for investors?

Kenya votes for its next President on 4th March. The opinion polls show that it is neck-and-neck between the two main candidates but an influential Kenyan political scientists has warned that the polls are wrong. Mutahi Ngunyi’s predicting a win for Uhuru Kenyatta and his Jubilee Coalition because of what he describes as ‘the tyranny of numbers’ - there are simply more registered voters from the ethnic groups that are likely to support Kenyatta than those for his rival Raila Odinga. But will Kenyans vote along ethnic lines – Ruth Alexander finds out. Also, was the Pope the subject of divine intervention when lightning struck St Peter’s Basilica at the Vatican just after he announced he was stepping down? Or was it just a coincidence. More or Less looks at the chances of this occurring.

This week Tim Harford asks how the figure of 1.2 billion Catholics world-wide is calculated. He also tests the claims of the controversial video, 'Muslim Demographics' shown at the Vatican by the Ghanaian Papal candidate Cardinal Peter Turkson.

This week Ruth Alexander looks at Manchester United versus Real Madrid in the last 16 of the Champions League. Real Manager Jose Mourinho says this was the match the "world has been waiting to see". It pitched two of Europe's biggest clubs against each other in what is a supposed to be a money spinner for broadcasters and sponsors alike. But how do we know how big the interest is? Manchester United claim 650 million fans worldwide, but how can we know? Nick Harris of SportingIntelligence.com and Richard Brinkman of KantarMedia help us look at the figures. Also: this round of the Champions League has been a statistical surprise. The rehearsal and the real draw threw up the same fixtures meaning that the same teams were picked to play each other in both draws. Statistician Michael Wallace helps us calculate the chances of this happening.

Canada has stopped distributing its smallest coin –the one cent or the penny. This week Ruth Alexander looks at why some countries get rid of their smallest coins and some just cannot part with them. Also which country has the coin with the smallest monetary value?

This week Ruth Alexander looks at the extraordinary case of Andreas Georgiou the head of the Greek statistics agency, Elstat. He is facing criminal charges for what amounts to statistical treason. It is a story that goes to the heart of the Greek debt crisis, that includes extreme office politics, alleged e-mail hacking and a statistician facing at least five years in prison. We speak to Economists Miranda Xafa and Professor Yanis Vourafafkis as well as Syriza MP Dimitris Tsoukalas. Also: do American football players die earlier than their fellow Americans?

A ‘new’ BMI calculation has been proposed by Oxford Mathematician Professor Nick Trefethen but does it really address the problem with a calculation that is over a century old. Body Mass Index was first calculated over 150 years ago and in recent years has become controversial for its imprecise nature. Ruth Alexander and Wesley Stephenson look at how it has developed and what it really tells us, if anything, about our health.

This week Ruth Alexander is looking at farmer suicides in India. But is it any more prevalent than in any other area of Indian society? Also what is the history behind the Lakh and the Crore in South Asia? It confused one contributor on the farmer suicide story and caused him to get the figures wrong by a factor of 10.

Episode 1 of Tim Harford's new series, Pop Up Economics, in which he tells a live audience short stories about fascinating people and ideas in economics.

Reports this week suggest that we are wasting 50 per cent of our food globally. It comes from a study by the Institute of Mechanical Engineers in the UK. Ruth Alexander discovers why this number is out of date and is likely to be much lower than half. Also are the values on Scrabble tiles correct? They were first assigned in the 1930s. With our changing language do we need to reassess the values. We speak to Joshua Lewis, a post-doctoral researcher at the University of California, San Diego about his new value system ‘Valetta’ and ask John Chew, Co-President of the North American SCRABBLE Players Association, what he thinks.

What does a 'guess the weight of the ox' competition tells us about a bloated and dysfunctional financial system? We find out in the Parable of the Ox written by John Kay of the Financial Times. The tale is told with the help of economics writer James Surowiecki as well as John Kay himself. It also features a brand new composition from the New Radiophonic Workshop.

What does a 'guess the weight of the ox' competition tells us about a bloated and dysfunctional financial system? We find out in the Parable of the Ox written by John Kay of the Financial Times. The tale is told with the help of economics writer James Surowiecki as well as John Kay himself. It also features a brand new composition from the New Radiophonic Workshop.

A special review of the year through the interesting, informative and idiosyncratic numbers of 2012.

A guide to 2012 in numbers - the most informative, interesting and idiosyncratic statistics of the year discussed by More or Less interviewees.

Tim Harford investigates the numbers in the debate on firearms deaths, and discovers the mathematics of juggling. This programme was first broadcast on the BBC World Service.

Tim Harford investigates gun crime statistics in the US. Plus, why death is not always the one hard fact that’s hard to fudge; the average age of first-time buyers; whether chocolate makes you clever; the statistical paradox of road collisions caused by deer; and the maths of juggling. Producer Ruth Alexander

This week: What is ‘rare’? When we say something is rare what do we mean? Lightning strikes which typically kill three people a year in the UK are often described as rare but how do we square that with a condition like motor neurone disease which is also described as rare yet kills 1500 people a year in the UK. Also we speak to Nassim Taleb about his book Anti-fragile.

Why was the estimate, in 2003, for Eastern Europeans coming to the UK so wrong? Which is better when communicating information words or numbers? Nassim Taleb explains anti-fragility And we'll debunk the oft quoted 'you're never more than 6ft from a rat'

Where does Nigeria’s plan to revise its GDP leave our understanding of growth in Sub-saharan Africa? And what is the chance of the Duchess of Cambridge having twins given she has severe morning sickness.

In light of the Royal pregnancy Tim Harford asks what severe morning sickness tells us about the chances of having twins. Yan Wong helps him look at the figures. We disentangle the Chancellor' Autumn Statement and ask: where is the economy really at? As Nigeria prepares to revise its GDP statistics with an expected jump of 40-60%, we ask how reliable are African GDP statistics? Another Daily Telegraph headline comes under scrutiny. And we return to our Lego tower and look at how Lego can be used to teach maths with Eugenia Cheng of Sheffiled University.

Kevin Pietersen has been widely praised as one of the best England batsmen of the current era and possibly of all time. But in the first test match he only scored 19. So can England really not do without him? Also why is Zero an even number?

On More or Less this week Tim Harford looks at three polls carried out to gauge the public’s opinion on press regulation gave vastly different answers despite being carried out by the same polling company. Tim talks to Peter Kellner, President of online polling company YouGov. Would you send Kevin Pietersen out to bat if your life depended on him scoring a century? Have two thirds of millionaires really left the country as claimed by the Daily Telegraph this week? What percentage of drinks might be affected by the introduction of a minimum price for alcohol. And how high could you build a Lego tower before the bottom brick collapses? Ruth Alexander dons her safety goggles to find out?