Nobel laureate Daniel Kahneman of Princeton University talks to Romesh Vaitilingam about wellbeing as an indicator of social progress, arguing that we need at least two measures of happiness – one that comes when you ask people how they feel right now (‘experience happiness’) and one that comes when you ask people how they think about their life (‘life evaluation’). The interview was recorded at a workshop on happiness research at the Centre for Economic Performance in London in October 2008.