Norm Chronicles

Michael Blastland & David Spiegelhalter The Norm Chronicles: stories and numbers about danger Profile Books 2013

Michael is the creator and presenter of BBC Radio 4’s More or Less, a popular program on mathematics. David is the Winton Professor for the Public Understanding of Risk at Cambridge University, UK.  He takes a a much broader view than is usual in finance and economics, where risk is defined to be purely probabilistic, with a blog on understanding uncertainty.

Main Body

The book introduces  Norm, Prudence and Kevin who have various ‘attitudes to risk’, and argues – with examples –  that the usual norm of a ‘neutral’ attitude to risk is not always appropriate.

Judgement Day (Conclusion)

   It’s become fashionable to blame people for their cognitive biases or failures of reasoning, but we think that … their reasoning is usually reasonable, for all their human ways.

[Independent] , objective probability .. doesn’t exist.

Nor … does the average person exist to whom the average risk is supposed to apply.

[Numeric probabilities] should be considered only as reasonable betting odds given what we know. {The] potential degree of refinement is often infinite.

DS says he has spent many years trying to work out why people find probability intuitively difficult and confusing. He has concluded that it is because it is intuitively difficult and confusing.

Dave Marsay

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