The fiasco in Iowa continues. It is now over 24 hours after the start of the caucuses and we have yet to receive a final count of the results. No word yet from the Iowa Democratic Party about when we will get the remaining 38% of precinct-level results (you can look at the 62% we do have online at the Washington Post).
But the results shouldn’t change that much between now and the final count, so I want to take some time to assess the accuracy of the polls released in the run-up to Iowa. The results are pretty revealing about both the current state and future of political polling.
To measure accuracy of each firm, I matched the current returns — Sanders 25%; Buttigieg 21%; Warren 19%; Biden 15%; Klobuchar 13% — with the last month of polls aggregated by FiveThirtyEight and compared each of the top 5 candidates’ projected vote shares in the polls versus their actual vote shares. I then took an average of those errors for each pollster. (In data analysis we call this the “mean average er…
