What's wrong with GDP?

We talk with economist Diane Coyle about what's wrong with our main measure of economic performance and how it impacts on politics. She tells us what we're missing in our measures of economic activity and she explains how we could do it better. Plus we discuss whether the unemployment figures still tell a true picture of the world of work and we ask whether the dollar's days as the global reserve currency may be coming to an end. Numbers and why they matter. With Helen Thompson and Chris Bickerton.