In the second of two provocative programmes, we look at pay, asking why there is still a pay gap several decades after the Equal Pay Act. Presenters Sophie Raworth and Justin Rowlatt want to find out why the average pay gap is 17 per cent. And it is not just professional curiosity; as parents of girls, the pair really want to know.

On their journey Sophie and Justin meet professionals, mums and academics, and do some of their own tests, asking whether it is just sexism at play or if there are more complex reasons. Could it be that women are actually choosing to earn less? And they find some shocking facts: in the US thin women earn more than fat women; girls who go to single-sex schools go on to earn more; and hundreds of thousands of women in the UK are illegally being paid less than their male counterparts.

The programme also features specially commissioned surveys that throw new light on the debate. There are plenty of arguments along the way, but Sophie and Justin do manage to reach a conclusion. Show less