Saturday, 8 January 2011

The Black Swan - book and movie

The philosophical use of the "black swan" relates to the "problem of induction" - perhaps the leading issue in Philosophy of Science. How many white swans would you need to see before it was acceptable to conclude that "all swans are white". The original statement of this occurred before the discovery, in Australia, of black swans, so when a philosopher argued for the generalisation, "all swans are white", it was supposed to a statement that everyone would have accepted as true.

The real significance, philosophically, of the discovery of black swans is that prior to that discovery, you had actually used all the evidence you had in a complete and correct way. Yet you are still incorrect in the generalised conclusion. It is not that generalised conclusions can sometimes be wrong - of course they can. It is more that you can correctly use all the information at your disposal and yet, still be wrong

An Australian Black Swan

Nassim Taleb has brought the phrase to a wider audience in respect of financial markets. There black swans occur regularly - the so-called 10-sigma events that pop up every few years. The credit crunch via sub-prime might be taken is such an event - not forcastable on the basis of all the evidence available to that point i.e. the 30% default rates that occured are 6x the previous high. How sensible is it to allow for such events? The answer is that it rarely makes for a good investment strategy - better to trade as if Black Swans don't occur, and hope one doesn't. And if it does, blame it on unforeseeable events

I was shocked to see the CEO of Heathrow describe the snow in December as a "black swan" event. Maybe if your airport is in Egypt, but snow in December in England is hardly unknown (or unknowable)

So when I heard about a movie called "The Black Swan", my initial though was that it might be a movie about the problem of induction, or maybe based on Taleb's book. Instead it is set in a New York ballet company and stars Natalie Portman. The current issue of Gorezone magazine (!!) has a long feature on it, comparing it to a David Cronenberg film. Apparently Natalie Portman's portrayal of the dancer forced to confront the experiences necessary to enable her to dance the black swan in Swan Lake, is possible Oscar-winning stuff

So though I am disappointed that the movie isn't a philosophical discussion, it is perhaps one we should try and see

The scary, red-eyed Natalie Portman.

Apparently Natalie Portman became quite ill filming the movie - such are the demands placed on a possible Oscar-winner

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