Donald MacKenzie rejoins the show to talk about his book An Engine, Not a Camera, which is about how financial models aren't designed to reflect the world economy, like a camera, but drive the world economy, like an engine. This means that a large part of economics is driven by trading that resembles a Reiner Knizia or 18XX game. It also means that trading and gambling can be pretty hard to differentiate.

You can read more about Donald's book here: https://mitpress.mit.edu/9780262633673/an-engine-not-a-camera/