Would you be willing to spend more money to avoid unlucky numbers? American consumers don’t have the same beliefs as Taiwanese, but they do think 13 is an unlucky number. Many American buildings don’t have a 13th floor, and U.S. businesses lose a large amount of money every Friday the 13th because people avoid important transactions on that day. Tom Kramer and I studied whether superstitious beliefs about Friday the 13th influence the choices American students make. Students were asked to choose between two bets: In the first bet students knew they could win a small sum of money and in the second bet students had to gamble