“Betting markets are much more accurate historically than polls,” he said. “There is a lot of money at stake, so the bookmakers carefully select which polls are worth looking at and which ones have a political bias. The Rasmussen polls have a consistent 2% Republican bias, but you don’t need to discard them, just factor the bias in. Other polls are so feeble that it’s akin to wildly throwing darts and hoping one hit the bull’s eye.”

The bettors themselves also influence the odds. Experts who are more likely to make correct predictions tend to stake the largest sums. The bookmakers know to ‘follow the money’ and pay attention to these punters when they set the odds.

Betting Markets ‘Trump’ the Polls when it comes to Presidential Forecasting | Economy Watch