Availability bias in action

Phil went on vacation to Panama (among other places). I said, Panama? Who goes to Panama? Phil said, What do you mean, who goes to Panama? I said, people go to Costa Rica, they go to Guatemala, who goes to Panama?

Phil replied:

According to http://www.thinkpanama.com/panama-weekly/category/panama-tourism and http://www.travelime.com/news/533/ the number of tourists that visited Panama last year was almost exactly the same as the number that visited Guatemala, 1.6M in each case.

OK.

2 thoughts on “Availability bias in action

  1. I would think that of all people, a Bayesian statistician would call that ignorance, not bias. Let's say you have observed is that 4 people you know have gone to Costa Rica, 3 people have gone to Guatemala and 0 have gone to Panama. To not believe that more people probably go to the former two, you would have to know the way in which your sample was unrepresentative or know the actual stats. Just because you were wrong doesn't mean you were biased!

    I realize this is a case of the word "bias" meaning two different things in statistics and psychology, but their definition has a misleading connotation of irrationality. The appropriate baseline for evaluating bias is the information you have and a tractable model of how that relates to an unknown state of the world, not the true state of the world itself. If it were the latter, all incorrect beliefs would be cases of bias!

  2. Ben,

    Yes, but I do know the way in which my sample is unrepresentative, and I had that information available to me ahead of time, had I thought about it. That's the point. Bias is prospective, variance is retrospective. I could've recognized this particular error ahead of time, hence I call it bias.

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