How do you count millionaires?

Can we be sure that thousands of millionaires are leaving the UK? How much do asylum seekers cost the state? Who will win a geeky bet on private school pupil numbers? What does a string quartet teach us about the woes of the National Health Service? Tim Harford investigates some of the numbers in the news. Presenter: Tim Harford Producers: Caroline Bayley, Natasha Fernandes and Bethan Ashmead-Latham Series producer: Tom Colls Production co-ordinator: Katie Morrison Sound mix: Sarah Hockley Editor: Richard Vadon