(In the spirit of GiveWell, only less obsessive.)
This lists major mistakes I’ve made in my posts that were objectively wrong, that somewhat affected my conclusions about things, and that required correction. It doesn’t list times I changed my opinion about things, times other people thought I was wrong but after reading all the arguments I still stand by my original position, or minor corrections of typos/details.
1. (10/20/13) In The Anti-Reactionary FAQ, I claimed that there was likely not much difference in crime between the distant past (especially Victorian England) and today, because although the reported burglary rate was up, the reported murder rate stayed the same, and murder is the most accurately recorded crime. Michael Anissimov points out that medical care has improved since that time, so that many things that would have been murders in the past are now only attempted murders, lowering the apparent murder rate by as much as five times. Discovering the mistake caused me to reverse my conclusion that crime has not been increasing since the Victorian age.
2. (6/29/14) In Invisible Women, I pointed out a paradox – how come women are joining the workforce, but GDP has not gone up proportionally to the increased number of workers? Pseudoerasmus explained that men were working less often and working fewer hours in a way that counterbalanced increased female employment. Discovering the mistake did not affect any “conclusion” since I was just asking the question, but the question turned out to be much easier and less weird than I had expected.
3. (4/22/15) In Growth Mindset 3: A Pox On Growth Your Houses, I claimed that a graph showed that most conditions of an educational experiment deteriorated over time, and that since this was very strange the study probably couldn’t be trusted. In fact, the graph was standardized in a way I didn’t notice, and showed only that those conditions did worse than the other conditions, without deteriorating outright. This made the study much more believable than I had thought. The author of the original study corrected me and I explained the correction in detail here. Discovering the mistake lessened my confidence in my conclusion (growth mindset isn’t very impressive and often fails outright) without entirely reversing it.
4. (12/1/15) In College And Critical Thinking, I claimed that a graph showed a u-shaped relationship between time spent in college and critical thinking, which suggested that the relationship between the two was too confusing and unpredictable to be very strong. In fact, commenter PSJ pointed out that this was only true of a small sample of two-year college students, and that most college students showed the expected linear relationship. Discovering the mistake strengthened my conclusion (that college probably does improve critical thinking skills at least in the short term).
5. (1/1/15) In my January 2016 links post, I noted that according to an article in Mother Jones, OxyContin abuse kills three times more people than homicide. Although the article was about OxyContin abuse, the specific statistic cited was about all fatal drug overdoses. This wouldn’t have been such a big deal except that it was linked by Marginal Revolution. Sorry, Marginal Revolution.
6. (3/26/16) In my March 2016 links post, I linked to a Wikipedia page about a radar detector detector detector detector. Rational Conspiracy has looked into it further and believes that was a hoax and there was no such thing. The hierarchy of radar detection most likely ends at radar detector detector detectors.
7. (8/26/16) In A Whiter Shade Of Candidate, I wrote that Donald Trump was doing relatively well among minorities in the Republican primary and so it was unfair to describe him as running a campaign based around “white power”. Although Trump did go on to do relatively well among the small subset of minorities who voted in the Republican primary, after winning the nomination he polls very poorly among minorities overall, and has run what seems to be an unusually racially tinged campaign. I do believe that some of this came from being forced into it – get called “the white supremacy candidate” enough times and eventually minorities will desert you, racists will flock to you, and you’ll be forced to make do with the base you have – but the claim that Donald Trump is not doing unusually badly among minorities no longer seems defensible.
8. Listing Mistake #7 above was itself a mistake. The exit polls show that Trump’s coalition was less white than Romney’s, and that he exceeded Romney in his share of both the black and Hispanic votes. The early polls that I was looking at when I declared Mistake 7 to be a mistake were wrong, and my original prediction was confirmed. As George Bernard Shaw once said, “The longer I live, the more I realize that I am never wrong about anything, and that all the pains I have so humbly taken to verify my notions have only wasted my time.”
Probably many other mistakes, but these are the ones I remembered to record. If you know of an objective mistake (not subjective disagreement!) that is not listed here, please let me know.