Assorted links by Tyler Cowen April 8, 2013 at 12:20 pm in 1. The world’s smallest robotic cleaner. 2. Henry on Fisman and Sullivan’s The Org. 3. Why don’t tech entrepreneurs buy more contemporary art? 4. The economics of witchcraft trials in the Congo. 5. The marketing of Magnus Carlsen. 6. Ian Cameron on the three-axes model, which I consider to be essentially true.