No calculations are necessary to see that we missed badly in our forecast of the U.K. election. … The most obvious problem for all forecasters was that the polling average had Labour and the Conservatives even on the night before the election. This was not just the average of the polls, it was the consensus. …
It’s our job as forecasters to report predictions with accurate characterizations of uncertainty, and we failed to achieve that in this election. We are not trying to make excuses here; we are trying to understand what went wrong. If we can find a few clear methodological culprits, that enables us to do better next time. CONT.
Ben Lauderdale (LSE), FiveThirtyEight