Before the birth of a baby boy today to Kate & William, the probability that the baby would in fact be a boy was 1/2, but what is the probability that the boy’s grandfather, Prince Charles, will ever ascend the throne? That is, what is the probability that Queen Elizabeth II will outlive Prince Charles or that Charles will voluntarily abdicate the throne in favor of his son William? According to some scholars, like Robin Hanson, one way to find out is to create a prediction market and let people place bets on these outcomes. But do prediction markets really work? Why don’t we start one to find out?