Tyler Cowen points to a fascinating paper that measures prosperity by looking at how much light shows up on a satellite image. It turns out that Nick Schulz was thinking along the same lines when he suggested that the cover for our new book should contrast a satellite photo of North Korea (dark) with one of the U.S. (lots of lights). (You may find a different cover pictured on some sites, but that was before the official cover was chosen.)
I really am excited about the book. I still don't know the exact publication date.