The idea of when to step down is front and centre in American politics as 81 year old Joe Biden continues in the Presidential race despite concerns about his mental agility. His performance in a recent TV debate has sown doubt among supporters with polls suggesting some are losing faith in his abilities. ‘Pass the torch Joe’ said one placard as he declared his intention to keep going.

Are the elderly blcoking the young if they cling on to powerful and influence ? Does it skew society even more in favour of older people who seem to have had it better when it comes to pensions, homeownership and the opportunity to save money? Gerontologists say that society is ageist, that most people are not like Biden and will hit barriers to staying in work once they get older. That these barriers have to be cleared because as the population gets older we all need to stay in the workforce for longer.

Wisdom is said to come with age but if you have a fulfilling job, how do you check that you are still capable of continuing? Will those around you tell you the truth ? Is it pride that keeps elderly people in powerful positions, a sense that they are irreplacable, an unwillingness to give up something that defines them and take on another role. What's the morality of stepping down?

Witnesses: Dorothy Byrne, President of Murray Edwards College Mary-Kate Cary, Professor of Politics at the Univeristy of Virginia David Sinclair, Chief Executive of the International Longevity Centre Dr Erica Benner, Political Philosopher and Historian

Panel: Inaya Folarin-Iman, Mona Siddiqui, Matthew Taylor,Ella Whelan

Presenter: Michael Buerk Producer: Catherine Murray Assistant Producer: Ruth Purser Production Co-ordinator: Nancy Bennie Editor: Tim Pemberton