The US presidential election campaign is fertile ground for anyone interested in the misuse of numbers. So this week's More or Less is devoted to examining questionable claims made by both sides.

The US presidential election campaign is fertile ground for anyone interested in the misuse of numbers.

So this week's More or Less is devoted to examining questionable claims made by both sides.

And – in a campaign which is being scrutinized more closely than ever by fact-checking websites – we ask - who fact-checks the fact-checkers?

Presenter: Yan Wong

Producer: Richard Knight