More or Less: Behind the Stats

What does the government mean when it commits to developing a “10-times more lethal” army? Why was the much-missed Sycamore Gap tree said to be worth a strikingly exact £622,191? Are there really twice as many people teaching Yoga as there are in the fishing industry? Is the number of workers per pensioner really falling from 4 to 3 to 2? And what did Donald Trump mean when he said the price of eggs had fallen by 400%? Tim Harford investigates some of the numbers in the news. If you want us to look at a number you think looks a bit suspicious, email the team - moreorless@bbc.co.uk Please note an earlier edition of the programme incorrectly stated that the new EU-UK fishing agreement would last 4 years. The agreement length is 12 years. More or Less is produced in partnership with the Open University. Presenter: Tim Harford Reporter: Lizzy McNeill Producer: Nicholas Barrett Series producer: Tom Colls Production co-ordinator: Brenda Brown Sound mix: Neil Churchill Editor: Richard Vadon

Exactly how many people live on our planet is one of those difficult-to-answer questions. The UN estimates is 8.2 billion, but that’s largely based on census data, which is certainly not a perfect measure. So when a recent study from Finland found that rural populations around the world had been underestimated by 50 to over 80%, the media got quite excited. This would be a big error - a 50% underestimate would mean the actual number of people in an area is double the number they thought there were. One newspaper in Spain - El Mundo - did its own sums and said this meant there were potentially 2 billion more people in the world than we currently think there are. But is it what the researchers in Finland actually meant? “Absolutely not,” says Josias Lang-Ritter, a researcher from University in Finland and a co-author of the study. Tim Harford speaks to Josias to figure out the right way of understanding the study. Presenter: Tim Harford Producer: Caroline Bayley Series producer: Tom Colls Production co-ordinator: Brenda Brown Sound mix: Nigel Appleton Editor: Richard Vadon

Tim Harford is here to sprinkle a refreshing shower of statistical insight over the parched lawns of misinformation. This week, we try to unpick the confusion over a claim made by London Mayor Sadiq Khan about the contribution skilled immigrants make to the nation’s finances. Mark Zuckerberg says that the average American has fewer than 3 friends. Is he right? Two doctors claim that up to 90% of Alzheimer’s disease can be prevented. Are they wrong? And Tim interviews an American, Catholic, philosopher of religion called Robert Prevost. Is he the pope? If you’ve seen a number in the news you think we should look at, email the team – moreorless@bbc.co.uk More or Less is produced in partnership with the Open University. Presenter: Tim Harford Reporter: Lizzy McNeill Producers: Nicholas Barrett and Nathan Gower Series producer: Tom Colls Production co-ordinator: Brenda Brown Sound mix: Nigel Appleton Editor: Richard Vadon

Picking Robert F. Kennedy Jr., a known vaccine sceptic, as the Secretary for Public Health might not be the most ‘out there’ thing the Trump administration has done but it certainly raised some eyebrows. Since his appointment Kennedy has been on a mission to ‘Make America Healthy again’ and has set his sights on finding ‘the cure’ for Autism. Autism Spectrum Disorder is a neurological and developmental disorder that can affect how someone communicates, socialises, learns and behaves. In the 1980’s one study estimated that 4 in 10,000 (1 in 2500) children in Wisconsin had an Autism diagnosis. Recent data from the Centres for Disease control states that 1 in 31 eight year olds in the US have the condition. Why have the numbers gone up? Is it due to environmental toxins as Robert Kennedy suggests or does the answer lie in the counting? Presenter/Producer: Lizzy McNeill Series Producer: Tom Colls Production Co-ordinator: Brenda Brown Studio Manager: Andrew Mills Editor: Richard Vadon

Every two years, the UN release their predictions for the future population of humanity – currently expected to peak in the 2080s at around 10.3 billion people. One of the things they use to work this out is the fertility rate, the number of children the average woman is expected to have in her lifetime. When this number falls below 2, the overall population eventually falls. In this episode of More or Less, we look at the fertility estimates for one country – Argentina. The graph of the real and predicted fertility rate for that country looks quite strange. The collected data – that covers up to the present day – shows a fertility rate that’s falling fast. But the predicted rate for the future immediately levels out. The strangeness has led some people to think that the UN might be underestimating the current fall in global fertility. To explain what’s going on we speak to Patrick Gerland, who runs the population estimates team in the United Nations Population Division. Presenter / producer: Tom Colls Production co-ordinator: Brenda Brown Sound mix: Sue Maillot Editor: Richard Vadon