Daily catch-up: more forecasting and a futuristic view from old London

The 'I knew it all along' effect, and some bonfire night news

Love this 1926 London Transport poster, including the old spelling of "to-day". It looks as if several of my Top 10 Unbuilt Buildings are in there. By Montague B Black. Thanks to Colin Smith.

• Talking of visions of the future, I am still going on about Superforecasting, the book by Philip Tetlock and Dan Gardner. Tetlock cites a wonderful example of hindsight bias from his research in recording forecasts. He asked experts in 1988 how likely it was that the Communist Party would lose its monopoly on power in the Soviet Union in the next five years. Three years later, the Soviet Union itself was dissolved.

So in 1992-93 I returned to the experts, reminded them of the question in 1988, and asked them to recall their estimates. On average, the experts recalled a number 31 percentage points higher than the correct figure. So the expert who thought there was only a 10 per cent chance might remember herself thinking there was a 40 or 50 per cent chance. There was even a case in which an expert who pegged the probability at 20 per cent recalled it as 70 per cent – which illustrates why hindsight bias is sometimes known as the "I knew it all along" effect.

He illustrates the effect by quoting a Saturday Night Live skit from 1991 in which the presenter introduces "the first of a series of debates among the five leading Democrats who are trying to avoid being forced by their party into a hopeless race against President George Bush". An actor playing Senator Bill Bradley says: "I am not a candidate for president in 1992." Congressman Dick Gephardt says: "I do not seek the party's nomination." And so on.

Tetlock's work on predictions took a long time, partly because some of the predictions were made over periods of years. He comments: "I began the experiment when Mikhail Gorbachev and the Soviet Politburo were key players shaping the fate of the world; by the time I started to write up the results, the USSR existed only on historical maps and Gorbachev was doing commercials for Pizza Hut."

• Moose Allain is turning out good lines faster than I can use them, so here is a bonus catch-up:

I predict there will be light showers this evening – or fireworks as they are usually called.

People sometimes tell me I'd make a great French shoe, but I'm not chaussure.

My imaginary friend’s staying over tonight. I’ve made up a bed for him.

During the Soviet era, dissidents were often sent to the Naughty Steppe.

Ping-pong: the smell of elastic.

"I feel like I've been herbivore" – vegetarian déjà vu.

Russian dolls are so full of themselves.

• And finally, thanks to Papillon ‏for this timely news flash:

"Police arrested two kids yesterday: one was drinking battery acid, the other was eating fireworks. They charged one and let the other off."