Diane Coyle talks with EconTalk host Russ Roberts about the ideas in her new book, The Soulful Science: What Economists Really Do and Why it Matters. The discussions starts with the issue of growth--measurement issues and what economists have learned and have yet to learn about why some nations grow faster than others and some don't grow at all. Subsequent topics include happiness research, the politics and economics of inequality, the role of math in economics, and policy areas where economics has made the greatest contribution.