# So will anybody ever trust the polls again? **URL:** \ **Category:** Politics & Elections\ **Created:** [November 4, 2020, 5:49am UTC](https://boards.straightdope.com/t/so-will-anybody-ever-trust-the-polls-again/924714 "2020-11-04T05:49:40Z")\ **Posts on this page:** 1\ **Showing post:** 221
**Author:** ![Lance\_Turbo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lance_turbo/32/6156_2.png) [@Lance\_Turbo](https://boards.straightdope.com/u/Lance_Turbo)\ **Post date:** [November 9, 2020, 10:46pm UTC](https://boards.straightdope.com/t/so-will-anybody-ever-trust-the-polls-again/924714/221 "2020-11-09T22:46:16Z")
> [@DMC](#): > > So that I don’t keep assuming what it is that you are measuring, can you share (or link to) the data, preferably for multiple races? I’ll repost an easier to digest example that I [posted in a different thread](https://boards.straightdope.com/t/looking-at-the-2020-election-what-conclusions-should-we-draw-about-poll-analysis-sites-like-538-etc/925089/12). Here’s a slope chart of PredictIt probabilities (debiased for favorite/longshot bias) compared to 538 for races where either gave any party a 10% or greater chance to win. There were 18 such races and no surprises outside these 18. 538 is taken from when they froze their forecast early 11/3. PredictIt data was the average of several observations on up to midnight on 11/2. So roughly the same timeframe. [![Google Photos](https://lh3.googleusercontent.com/pw/AP1GczMA8rqzRdU0aVEPlkZ2BrVX9jGaClVUlE-K52hESFtK1exOtB6DlKFDhZ4pzlxvWqLmQHltLR7iUnMxGRP2_nqi2PpYzdIvpBvfFstKyg5fv7mGX4U=w600-h315-p-k "New item by Keith S") ](https://photos.app.goo.gl/j8eupqQzYFM6KjBw8) 538 was more Biden leaning than PredictIt pretty much across the board. Here’s that same info in table form with a column for results. | Race | EV | PredictIt | 538 | Result | | --- | --- | --- | --- | --- | | SC | 9 | 0.004 | 0.100 | 0 | | AK | 3 | 0.015 | 0.149 | 0 | | MT | 3 | 0.027 | 0.180 | 0 | | IA | 6 | 0.140 | 0.399 | 0 | | OH | 18 | 0.162 | 0.453 | 0 | | TX | 38 | 0.238 | 0.382 | 0 | | GA | 16 | 0.383 | 0.582 | 1 | | FL | 29 | 0.417 | 0.691 | 0 | | ME-02 | 1 | 0.520 | 0.573 | 0 | | NC | 15 | 0.561 | 0.639 | 0 | | AZ | 11 | 0.645 | 0.680 | 1 | | PA | 20 | 0.749 | 0.843 | 1 | | NE-02 | 1 | 0.837 | 0.717 | 1 | | MI | 16 | 0.849 | 0.947 | 1 | | NV | 6 | 0.876 | 0.878 | 1 | | WI | 10 | 0.887 | 0.944 | 1 | | MN | 10 | 0.897 | 0.958 | 1 | | NH | 5 | 0.910 | 0.891 | 1 | If you calculate [Mean Squared Error](https://en.wikipedia.org/wiki/Mean_squared_error) across these 18 races, you get: PredictIt → 0.0849 538 → 0.1225 Lower is better. --- _[View the full topic](https://boards.straightdope.com/t/so-will-anybody-ever-trust-the-polls-again/924714)._