Genetics and Prevention of Alzheimer's Disease

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