Everyday risks: when statistics can't predict the future
Statistics, it seems, can reveal our chances of being affected by anything from crime to serious illness. But number-crunching itself is a hazardous business
Michael Blastland and David Spiegelhalter The Observer, Saturday 8 June 2013
We love data. For the past two years we have crunched numbers about dangers of every kind. And there are plenty of dangers about.
But - a big but - we're certainly not calculating machines. In fact, if there were such a thing as a risk-calculating machine that claimed to give you objective odds on danger, we'd be the first to warn of malfunctions. That's partly because although we think the numbers matter, they can never be the final word: the stories people tell are big influences on their sense of where danger lies - and why shouldn't they be? - since neither source of evidence, neither numbers nor stories is perfect. Each has strengths and weaknesses.
This is a perhaps surprising conclusion from writers at times almost geeky enough to have two hoods on our anoraks; that we think risk is seldom objective, nor solely a property of the world out there, but intimately bound up with our own perspectives, and so personal perspectives on danger are, usually, perfectly reasonable. More than that, we think they're essential. In fact, we think that one of the hazards with hazards is the way that some people use risk numbers almost as if they can foretell your fate. We prefer to think of risk as typically more like an uncertain bet on a horse using scraps of imperfect information mixed with your own judgment: the horse might come in. Or it might not?
So there are plenty of ways in which our sense of risk can be distorted, plenty of ways in which people can get the dangers wrong, and plenty more in which the numbers can be deceptive, too.
In the end, if we had to offer advice to the wary about risk, it would be to try to get to know the data that matter to you, get to know your own mind and the stories that influence you, and so learn how both stories and numbers can help? and deceive. Then do what you feel like.
Here are just five more of the hazards about hazards.
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