Nobel prize: Why are some countries so much richer than others?

The question of why some countries are rich and some poor has been described as the most important question in economics. Perhaps that is why the Royal Swedish Academy of Sciences awarded the Nobel Memorial Prize in Economics to Daron Acemoglu, Simon Johnson and James Robinson for their work on the importance of institutions in the economic fortunes of nation states. Tim Harford explains the economic theory that underpins their award.Presenter: Charlotte McDonald Reporter: Tim Harford Producer: Bethan Ashmead Latham Series producer: Tom Colls Production co-ordinator: Katie Morrison Sound mix: Giles Aspen Editor: Richard Vadon