In the 2012 presidential election, Silver correctly predicted the winner of all 50 states and the District of Columbia. Between his electoral and popular vote predictions, he was by some measures the most successful major forecaster of the presidential election. Silver's predictions of U.S. Senate races were correct in 31 of 33 states; he predicted Republican victory in North Dakota and Montana, where Democrats won. --WikipediaNate Silver joins Hal Varian (Google's Chief Economist) to talk about his book "The Signal and the Noise: Why So Many Predictions Fail-but Some Don't" and answer Googler questions.