With about two weeks to go until Election Day, a number of the forecasters have been investigating the potential accuracy of polling averages. See the discussion by Mark Blumenthal, Nate Silver, and Sean Trende, as well as the earlier analysis by Josh Katz at The Upshot. The main conclusion is that poll averages where one candidate leads by more than about three points are likely to call the winner correctly, but closer races are still up in the air.