Do not expect the unexpected

If you call up a random American and ask them to guess the demographics of America, here is what they’ll tell you, on average:

If you ask what Americans are likely to die of, they’ll tell you, on average:

And if you ask about corporations and government, they’ll tell you, on average:

From these guesses, what should you conclude?

Here is what I conclude:

If you ask people to estimate a low percentage that they don’t know, they’re going to overestimate it. Maybe they’re hedging toward 50%. Maybe it’s easier to imagine the specific thing being estimated than the amorphous remainder. Maybe rare events are amplified by a media system that feeds our desire for novelty, originating from an evolutionary environment where we had to learn about dangers without sufficient statistics. Or maybe it’s just the fact that if you guess a random percentage, it’s more likely to pull the average toward 50% than away.

Whatever the reason, remember that rare events are usually overestimated. Do not expect the unexpected.18


  1. Gallup (2001) 

  2. Kieran Healy reporting on the General Social Survey (2000)  2

  3. US Census (2019 estimate) 

  4. Gallup (2019) 

  5. Gallup (2018) 

  6. Perils of Perception 2016 

  7. Perils of Perception 2018 

  8. Pew (2013) 

  9. Perils of Perception 2020  2 3

  10. AEI reporting on data from Reason-Rupe (2013) and Yahoo!Finance 

  11. KFF (2013) 

  12. WorldPublicOpinion (2010) 

  13. PIPA (2001) 

  14. Ipsos (2020) 

  15. Gallup (2019) 

  16. Over many polls, something like 36%–62% of Americans profess to believe in ghosts. 

  17. Gallup (1983–2019) 

  18. In prediction markets and other aggregators of judgment, Tetlock and others have found that aggregated predictions are usually hedged toward 50% and can be improved by a bluntly ‘extremizing’ them away from 50% and toward 0% or 100%. Here’s a paper by Baron et al discussing two reasons why it makes sense to extremize aggregated beliefs. And here’s a reveiew of Superforecasting by Jason Collins that mentions the topic.