“Often wrong, always certain”, goes a saying I once heard about economists. Frankly, I hate admitting when I’m wrong or when I don’t know something (don’t try to use that against me in an argument, I’ll totally deny that it applies in that case). I force myself to do it, and I think I succeed most of the time, but it is very unpleasant.

I think the same thing applies to other people. We would rather take an “educated guess” than to say “I don’t know” and we would rather defend our original point in an argument even though halfway through we may have started wondering (very very deep down) if we’re wrong.

A few days ago, I realized that I actually have great data to test this hypothesis. In a survey experiment pilot my colleague Olga Shurchkovand I ran recently, we asked people two multiple choice questions: (1) what is the current concentration of CO2 in the atmosphere? and (2) what is the “albedo effect”? We included “I don’t know” as an answer option and used the number of correct answers as a gauge for objective knowledge about climate science (there was another question asking people to name greenhouse gases, but that one is more complicated because there are multiple correct answers).

Our sample was not necessarily representative of the US (Amazon MTurk workers), but there is definitely a wide range of various demographic and economic characteristics in our data. We never looked at what fraction of people answered “I don’t know”, but my prior was that it was low. I got really excited to have some data to test my hypothesis. I was even going to run an informal survey on Facebook, making up a fake city and asking people which continent it was located on to see how many of my friends would admit that they didn’t know.

But I decided to look at the survey data first, and frankly I was shocked. 224 out of 361 respondents (62%) admitted they didn’t know the CO2 concentration in the atmosphere (22% chose the right answer and the rest chose a wrong answer, if you’re wondering). 200 (55%) admitted that they didn’t know what the albedo effect was (20% got it right). Apparently the majority of people have no problem admitting when they don’t know something (at least on a survey). Even though my original hypothesis didn’t pan out, I thought the results might be interesting to some of my blog readers.

And there you go: I was wrong.