The world's population is ageing. According to the UN the number of people aged 60 or over is growing faster than all younger age groups. This is putting new pressures on relationships between generations. In richer countries, younger people are not accumulating the wealth their predecessors did and that's causing tensions. In the developing world, urbanisation and technology are challenging traditional family dynamics. So, how can the young and the old stay connected in a fast changing world? As part of the BBC's Crossing Divides season, Carrie Gracie is joined by a panel of expert guests in front of an audience of international students.