As we are all aware from Thinking, Fast and Slow, one of the largest decision-making errors we make is the Base Rate Fallacy. Just to remind you—the error is that we don’t correctly apply probability reference classes to ourselves. Two examples:
-
The likelihood of winning the lottery is x, but I am more likely to win than x.
-
1 in x people will get lung cancer from smoking, but I won’t. This is all well and good, but my question is where you go about actually finding x. In other words—where do you find your base rates? Any particular repositories of knowledge that we should know about? Any processes that we should follow? Let’s say you’ve decided you want to reduce your risk of getting Coronary Heart Disease. Is your first stop to go to WHO and gather their list of recommendations, or something else?
I often use the Office for National Statistics (UK)
Comment
Interesting. So let’s say you wanted to minimise your risks of CHD as the OP mentioned—you would just go here and find out the highest correlates and trust them enough to base your whole gamble on?
Comment
To be honest I’d just google that one but that didn’t seem like very useful advice! My googling got me almost straight to this risk calculator used by NHS Scotland. Cross check this with a few other references from google and that’s probably as good as anything I’d work out myself by going to the data—it’s a well studied issue. ONS is useful for base rates where google fails me.