“One way to think of money is to use William Gibson’s famous description of cyberspace: a consensual hallucination. We accept it as payment because other people accept it as payment. We think that prices will be pretty stable because other people think that prices will be pretty stable. This takes us away from the mechanical quantity theory of money. Instead it suggests that there are multiple equilibria, one of which we happen to be experiencing. The behavior of prices is part of our consensual hallucination.”