What exactly is economics? Science or art? An explanation of our society based on observable, demonstrable law or is it an attempt to systematise the unknowable: the mysteries of the human mind?

Peter Day puts these questions to the economist and bestselling author of Nudge, Professor Richard Thaler, one of the founding fathers of behavioural economics. This relatively new branch of the dismal science tries to shed light on the way people make choices in their everyday lives and why subtle changes in the way options are framed can make big differences in how we behave.