1. Neptune's Brood is more heavily based on David Graeber's work on Debt (notably Debt: The First 5000 years).

1a. If you feel inclined to read Neptune's Brood, I've got one big regret: I wrote it circa 2010-11, before BitCoin really took off in the public eye, and used the term "bitcoin" for a not-like-our-BtC-honest cryptocurrency. (If I'd known BtC was going to take off that way the year the book came out, I'd have come up with a different name.)

2. Paul Krugman is a cool person to go drinking with in a pub :)