The linked story doesn’t cite another paper, so it’s hard to guess their actual source. Generally, academic research takes a while to be written and get published; the 2015 version of the paper seems to be the latest draft in circulation. It’s not uncommon to share and cite papers before they get published.
So to be clear, in his November 1, 2013 article, David Ignatius had access to forecasting data from the period August 1, 2013 through May 9, 2014!! (See section 5 of the Seth Goldstein paper underlying your analysis).
The linked story doesn’t cite another paper, so it’s hard to guess their actual source. Generally, academic research takes a while to be written and get published; the 2015 version of the paper seems to be the latest draft in circulation. It’s not uncommon to share and cite papers before they get published.
Thanks for the clarification, @Misha-Yagudin.
So to be clear, in his November 1, 2013 article, David Ignatius had access to forecasting data from the period August 1, 2013 through May 9, 2014!! (See section 5 of the Seth Goldstein paper underlying your analysis).
That, my friend, is quite the feat!!
Good catch, Tim! Well, at least Good Judgement Inc. (and some papers I’ve seen) cite Goldstein et al (2015) straight after David Ignatius’s 30% claim: https://goodjudgment.com/resources/the-superforecasters-track-record/superforecasters-vs-the-icpm/
If you by any chance have another paper[1] or resource in mind regarding the 30% claim, I would love to include it in the review.
Note that Goldstein et al don’t make that claim themselves, their discussion and conclusion are nuanced.
Christian Ruhl confirms that results from ACE were leaked early to Ignatius.