this blog is girtby.net

Pedantry Ahoy

Consider the following (my emphasis):

As of this writing (only a few days before the election) we believe that the chances of a definitive “call” for who will be the president by 2 am Eastern Time is a 50/50 chance at best.

To me, this is saying that the person doesn’t know (or isn’t saying) the odds of a result by 2am ET, but whatever they are, they are less than 50/50. No justification is given as to why 50/50 would be the upper bound, or indeed why there is no actual estimate of the odds.

OK, so I’m being really pedantic, and it’s just one sentence anyway, and really, what does it matter?

Well, it matters because this quote is from a pollster, and frankly they should know (or explain) better.

It’s just a fancy pollsters way of saying “we think it’s more likely than not that we won’t get a result by [etc]”. Which isn’t very accurate, of course, but people do it all the time—and while pollsters may say they’re better than laypeople at predicting things, they’re clearly not!

People are famously terrible at probability, though—just yesterday in all the Melbourne Cup brouhaha I was listening to very smart business-types tell me that because pokies have a guaranteed payout of say 90% you can game them by waiting for someone to have a long losing streak and then getting on their machine (this may have more to do with people’s understanding of guaranteed payouts than of probability, but I don’t know). They looked at me like I was insane when I started in on the gambler’s fallacy.

Now that’s pedantry!