5 March 2015updated 05 Oct 2023 8:54am

The rise of the SNP is a phenomenon without precedent – new predictions are guesswork

Like the US housing crisis, the rise of the SNP is an ‘out-of-sample’ event. It’s unclear how forecasters should react.

(Photo By Jim Murphy reads to children on World Book Day. Photo: Getty.)

If you’ve driven your car 20,000 times and never crashed, does that mean you won’t crash if you drive it drunk?

You can’t answer this question with any basis. Without any past data, you just have blind confidence or innate doubt, depending on your disposition. This is the prototypical example of an ‘out-of-sample’ event, used by Nate Silver in his 2012 book The Signal and The Noise. We don’t have any idea how to predict what will happen because we’ve never driven drunk (in this hypothetical).