Predicting is hard, especially about the future, runs an old joke. Does the “wisdom” of crowds help? There’s a long line of research suggesting it does. Combining forecasts from several models, for example, has an encouraging track record of outperforming any one model as a general rule. The latest twist on this idea arises from betting markets. As researchers study these sites and compares their forecasts with the usual suspects, the results reaffirm the value of the crowd’s view.