In his heyday, Irving Fisher was perhaps the most famous economist on the planet.
If remembered at all today, it is for one statement, days before the great Wall Street Crash: "Stock prices have reached what looks like a permanently high plateau."
The thing about Irving Fisher, however, is that he's not alone. John Maynard Keynes made much the same error.
Keynes, however, died rich - while Fisher was ruined by his mistake.
What explains the difference? Well, to reduce to the length of a tweet: John Maynard Keynes changed his mind, and Fisher did not.
The question of how and why we change our minds is a fascinating one. I recommend "Superforecasting" by @PTetlock and @dgardneramzn.to/3tlo56v
and...
But it's the closing rule in "The Data Detective" because it's so important. As Keynes never actually said - but lived - "When the facts change, I change my opinion. What do you do?"
The facts often change. New data comes in. Events develop. And yet, like poor Irving Fisher, we find it hard to take new information on board.
A rival of Fisher's, not without sympathy, said that Fisher's problem was "he thinks the world is ruled by figures instead of feelings".
In my book, I argue that it is ruled by both.
To be wise about statistics, we need to be wiser about ourselves.
Help me, hivemind! I have three related questions about your experiences of email: 1) What piece of email behaviour most annoys you?
(EG Sending pdfs and saying "please see attached document" instead of just putting it in the email.)
2) What fresh hell - some new, terrible fad - have you seen with respect to email?
(EG "Just re-sending this to get it to the top of your inbox.")
3) Have you seen any pieces of email ettiquette that made you think, "ah, yes, that's the way to do it"?
(EG Moving someone to bcc, and saying you're doing it, to acknowledge that they should no longer be copied in to an irrelevant exchange.)
If you wanted to reduce the advice in "The Data Detective" / "How To Make The World Add Up" to a bumper sticker (although, please don't) this would be a strong candidate.
I argued back at Rule Zero that indiscriminate doubt was as harmful as indiscriminate belief. It's all too easy to let scepticism curdle into cynicism.
Phillips grew up in a rural part of New Zealand. Long bike ride / train ride to school. As a boy, he made a kind of music stand on his handelabrs and used to cycle to school with textbooks propped on it. Not a complete success.
More successful was when as a teenager (14, IIRC) he renovated a neighbour's abandoned truck. Insert your own metaphor about restarting economies after all hope is lost here.
RULE NINE
*Remember Misinformation Can Be Beautiful Too*
I love dazzle camouflage - century-old solution to the problem of camouflaging a ship with a smokestack on an ever-changing sea from u-boats...
The use of dazzling patterns broke up the outlines of the ship, making it hard for periscope operators peering through a tiny 'scope to discern speed and direction. Slow-moving torpedoes would then miss.
Modern dataviz reminds me of dazzle camouflage. Beautiful, yes - but often they misdirect, intentionally or unintentionally.
Adam Smith famously attributed the "wealth of nations" to the increasing division of labour. People specialised in narrower, more refined tasks, giving us three advantages...
Specialisation boosts output, said Smith, because 1) We perfect our skills; 2) We avoid the distraction of task-switching; 3) We use, and even invent, specialised equipment.
But modern office work fits uneasily into this picture.